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  • Delegate performance of Roslyn Sept 2012 CTP is impressive

    - by dotneteer
    I wanted to dynamically compile some delegates using Roslyn. I came across this article by Piotr Sowa. The article shows that the delegate compiled with Roslyn CTP was not very fast. Since the article was written using the Roslyn June 2012, I decided to give Sept 2012 CTP a try. There are significant changes in Roslyn Sept 2012 CTP in both C# syntax supported as well as API. I found Anoop Madhisidanan’s article that has an example of the new API. With that, I was able to put together a comparison. In my test, the Roslyn compiled delegate is as fast as C# (VS 2012) compiled delegate. See the source code below and give it a try. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Diagnostics; using Roslyn.Compilers; using Roslyn.Scripting.CSharp; using Roslyn.Scripting; namespace RoslynTest { class Program { public Func del; static void Main(string[] args) { Stopwatch stopWatch = new Stopwatch(); Program p = new Program(); p.SetupDel(); //Comment out this line and uncomment the next line to compare //p.SetupScript(); stopWatch.Start(); int result = DoWork(p.del); stopWatch.Stop(); Console.WriteLine(result); Console.WriteLine("Time elapsed {0}", stopWatch.ElapsedMilliseconds); Console.Read(); } private void SetupDel() { del = (s, i) => ++s; } private void SetupScript() { //Create the script engine //Script engine constructor parameters go changed var engine=new ScriptEngine(); //Let us use engine's Addreference for adding the required //assemblies new[] { typeof (Console).Assembly, typeof (Program).Assembly, typeof (IEnumerable<>).Assembly, typeof (IQueryable).Assembly }.ToList().ForEach(asm => engine.AddReference(asm)); new[] { "System", "System.Linq", "System.Collections", "System.Collections.Generic" }.ToList().ForEach(ns=>engine.ImportNamespace(ns)); //Now, you need to create a session using engine's CreateSession method, //which can be seeded with a host object var session = engine.CreateSession(); var submission = session.CompileSubmission>("new Func((s, i) => ++s)"); del = submission.Execute(); //- See more at: http://www.amazedsaint.com/2012/09/roslyn-september-ctp-2012-overview-api.html#sthash.1VutrWiW.dpuf } private static int DoWork(Func del) { int result = Enumerable.Range(1, 1000000).Aggregate(del); return result; } } }  Since Roslyn Sept 2012 CTP is already over a year old, I cannot wait to see a new version coming out.

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  • Is it OK to repeat code for unit tests?

    - by Pete
    I wrote some sorting algorithms for a class assignment and I also wrote a few tests to make sure the algorithms were implemented correctly. My tests are only like 10 lines long and there are 3 of them but only 1 line changes between the 3 so there is a lot of repeated code. Is it better to refactor this code into another method that is then called from each test? Wouldn't I then need to write another test to test the refactoring? Some of the variables can even be moved up to the class level. Should testing classes and methods follow the same rules as regular classes/methods? Here's an example: [TestMethod] public void MergeSortAssertArrayIsSorted() { int[] a = new int[1000]; Random rand = new Random(DateTime.Now.Millisecond); for(int i = 0; i < a.Length; i++) { a[i] = rand.Next(Int16.MaxValue); } int[] b = new int[1000]; a.CopyTo(b, 0); List<int> temp = b.ToList(); temp.Sort(); b = temp.ToArray(); MergeSort merge = new MergeSort(); merge.mergeSort(a, 0, a.Length - 1); CollectionAssert.AreEqual(a, b); } [TestMethod] public void InsertionSortAssertArrayIsSorted() { int[] a = new int[1000]; Random rand = new Random(DateTime.Now.Millisecond); for (int i = 0; i < a.Length; i++) { a[i] = rand.Next(Int16.MaxValue); } int[] b = new int[1000]; a.CopyTo(b, 0); List<int> temp = b.ToList(); temp.Sort(); b = temp.ToArray(); InsertionSort merge = new InsertionSort(); merge.insertionSort(a); CollectionAssert.AreEqual(a, b); }

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  • MVC 2 Entity Framework View Model Insert

    - by cannibalcorpse
    This is driving me crazy. Hopefully my question makes sense... I'm using MVC 2 and Entity Framework 1 and am trying to insert a new record with two navigation properties. I have a SQL table, Categories, that has a lookup table CategoryTypes and another self-referencing lookup CategoryParent. EF makes two nav properties on my Category model, one called Parent and another called CategoryType, both instances of their respective models. On my view that creates the new Category, I have two dropdowns, one for the CategoryType and another for the ParentCategory. When I try and insert the new Category WITHOUT the ParentCategory, which allows nulls, everything is fine. As soon as I add the ParentCategory, the insert fails, and oddly (or so I think) complains about the CategoryType in the form of this error: 0 related 'CategoryTypes' were found. 1 'CategoryTypes' is expected. When I step through, I can verifiy that both ID properties coming in on the action method parameter are correct. I can also verify that when I go to the db to get the CategoryType and ParentCategory with the ID's, the records are being pulled fine. Yet it fails on SaveChanges(). All that I can see is that my CategoryParent dropdownlistfor in my view, is somehow causing the insert to bomb. Please see my comments in my httpPost Create action method. My view model looks like this: public class EditModel { public Category MainCategory { get; set; } public IEnumerable<CategoryType> CategoryTypesList { get; set; } public IEnumerable<Category> ParentCategoriesList { get; set; } } My Create action methods look like this: // GET: /Categories/Create public ActionResult Create() { return View(new EditModel() { CategoryTypesList = _db.CategoryTypeSet.ToList(), ParentCategoriesList = _db.CategorySet.ToList() }); } // POST: /Categories/Create [HttpPost] public ActionResult Create(Category mainCategory) { if (!ModelState.IsValid) return View(new EditModel() { MainCategory = mainCategory, CategoryTypesList = _db.CategoryTypeSet.ToList(), ParentCategoriesList = _db.CategorySet.ToList() }); mainCategory.CategoryType = _db.CategoryTypeSet.First(ct => ct.Id == mainCategory.CategoryType.Id); // This db call DOES get the correct Category, but fails on _db.SaveChanges(). // Oddly the error is related to CategoryTypes and not Category. // Entities in 'DbEntities.CategorySet' participate in the 'FK_Categories_CategoryTypes' relationship. // 0 related 'CategoryTypes' were found. 1 'CategoryTypes' is expected. //mainCategory.Parent = _db.CategorySet.First(c => c.Id == mainCategory.Parent.Id); // If I just use the literal ID of the same Category, // AND comment out the CategoryParent dropdownlistfor in the view, all is fine. mainCategory.Parent = _db.CategorySet.First(c => c.Id == 2); _db.AddToCategorySet(mainCategory); _db.SaveChanges(); return RedirectToAction("Index"); } Here is my Create form on the view : <% using (Html.BeginForm()) {%> <%= Html.ValidationSummary(true) %> <fieldset> <legend>Fields</legend> <div> <%= Html.LabelFor(model => model.MainCategory.Parent.Id) %> <%= Html.DropDownListFor(model => model.MainCategory.Parent.Id, new SelectList(Model.ParentCategoriesList, "Id", "Name")) %> <%= Html.ValidationMessageFor(model => model.MainCategory.Parent.Id) %> </div> <div> <%= Html.LabelFor(model => model.MainCategory.CategoryType.Id) %> <%= Html.DropDownListFor(model => model.MainCategory.CategoryType.Id, new SelectList(Model.CategoryTypesList, "Id", "Name"))%> <%= Html.ValidationMessageFor(model => model.MainCategory.CategoryType.Id)%> </div> <div> <%= Html.LabelFor(model => model.MainCategory.Name) %> <%= Html.TextBoxFor(model => model.MainCategory.Name)%> <%= Html.ValidationMessageFor(model => model.MainCategory.Name)%> </div> <div> <%= Html.LabelFor(model => model.MainCategory.Description)%> <%= Html.TextAreaFor(model => model.MainCategory.Description)%> <%= Html.ValidationMessageFor(model => model.MainCategory.Description)%> </div> <div> <%= Html.LabelFor(model => model.MainCategory.SeoName)%> <%= Html.TextBoxFor(model => model.MainCategory.SeoName, new { @class = "large" })%> <%= Html.ValidationMessageFor(model => model.MainCategory.SeoName)%> </div> <div> <%= Html.LabelFor(model => model.MainCategory.HasHomepage)%> <%= Html.CheckBoxFor(model => model.MainCategory.HasHomepage)%> <%= Html.ValidationMessageFor(model => model.MainCategory.HasHomepage)%> </div> <p><input type="submit" value="Create" /></p> </fieldset> <% } %> Maybe I've just been staying up too late playing with MVC 2? :) Please let me know if I'm not being clear enough.

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  • Auto-hydrate your objects with ADO.NET

    - by Jake Rutherford
    Recently while writing the monotonous code for pulling data out of a DataReader to hydrate some objects in an application I suddenly wondered "is this really necessary?" You've probably asked yourself the same question, and many of you have: - Used a code generator - Used a ORM such as Entity Framework - Wrote the code anyway because you like busy work     In most of the cases I've dealt with when making a call to a stored procedure the column names match up with the properties of the object I am hydrating. Sure that isn't always the case, but most of the time it's 1 to 1 mapping.  Given that fact I whipped up the following method of hydrating my objects without having write all of the code. First I'll show the code, and then explain what it is doing.      /// <summary>     /// Abstract base class for all Shared objects.     /// </summary>     /// <typeparam name="T"></typeparam>     [Serializable, DataContract(Name = "{0}SharedBase")]     public abstract class SharedBase<T> where T : SharedBase<T>     {         private static List<PropertyInfo> cachedProperties;         /// <summary>         /// Hydrates derived class with values from record.         /// </summary>         /// <param name="dataRecord"></param>         /// <param name="instance"></param>         public static void Hydrate(IDataRecord dataRecord, T instance)         {             var instanceType = instance.GetType();                         //Caching properties to avoid repeated calls to GetProperties.             //Noticable performance gains when processing same types repeatedly.             if (cachedProperties == null)             {                 cachedProperties = instanceType.GetProperties().ToList();             }                         foreach (var property in cachedProperties)             {                 if (!dataRecord.ColumnExists(property.Name)) continue;                 var ordinal = dataRecord.GetOrdinal(property.Name);                 var isNullable = property.PropertyType.IsGenericType &&                                  property.PropertyType.GetGenericTypeDefinition() == typeof (Nullable<>);                 var isNull = dataRecord.IsDBNull(ordinal);                 var propertyType = property.PropertyType;                 if (isNullable)                 {                     if (!string.IsNullOrEmpty(propertyType.FullName))                     {                         var nullableType = Type.GetType(propertyType.FullName);                         propertyType = nullableType != null ? nullableType.GetGenericArguments()[0] : propertyType;                     }                 }                 switch (Type.GetTypeCode(propertyType))                 {                     case TypeCode.Int32:                         property.SetValue(instance,                                           (isNullable && isNull) ? (int?) null : dataRecord.GetInt32(ordinal), null);                         break;                     case TypeCode.Double:                         property.SetValue(instance,                                           (isNullable && isNull) ? (double?) null : dataRecord.GetDouble(ordinal),                                           null);                         break;                     case TypeCode.Boolean:                         property.SetValue(instance,                                           (isNullable && isNull) ? (bool?) null : dataRecord.GetBoolean(ordinal),                                           null);                         break;                     case TypeCode.String:                         property.SetValue(instance, (isNullable && isNull) ? null : isNull ? null : dataRecord.GetString(ordinal),                                           null);                         break;                     case TypeCode.Int16:                         property.SetValue(instance,                                           (isNullable && isNull) ? (int?) null : dataRecord.GetInt16(ordinal), null);                         break;                     case TypeCode.DateTime:                         property.SetValue(instance,                                           (isNullable && isNull)                                               ? (DateTime?) null                                               : dataRecord.GetDateTime(ordinal), null);                         break;                 }             }         }     }   Here is a class which utilizes the above: [Serializable] [DataContract] public class foo : SharedBase<foo> {     [DataMember]     public int? ID { get; set; }     [DataMember]     public string Name { get; set; }     [DataMember]     public string Description { get; set; }     [DataMember]     public string Subject { get; set; }     [DataMember]     public string Body { get; set; }            public foo(IDataRecord record)     {         Hydrate(record, this);                }     public foo() {} }   Explanation: - Class foo inherits from SharedBase specifying itself as the type. (NOTE SharedBase is abstract here in the event we want to provide additional methods which could be overridden by the instance class) public class foo : SharedBase<foo> - One of the foo class constructors accepts a data record which then calls the Hydrate method on SharedBase passing in the record and itself. public foo(IDataRecord record) {      Hydrate(record, this); } - Hydrate method on SharedBase will use reflection on the object passed in to determine its properties. At the same time, it will effectively cache these properties to avoid repeated expensive reflection calls public static void Hydrate(IDataRecord dataRecord, T instance) {      var instanceType = instance.GetType();      //Caching properties to avoid repeated calls to GetProperties.      //Noticable performance gains when processing same types repeatedly.      if (cachedProperties == null)      {           cachedProperties = instanceType.GetProperties().ToList();      } . . . - Hydrate method on SharedBase will iterate each property on the object and determine if a column with matching name exists in data record foreach (var property in cachedProperties) {      if (!dataRecord.ColumnExists(property.Name)) continue;      var ordinal = dataRecord.GetOrdinal(property.Name); . . . NOTE: ColumnExists is an extension method I put on IDataRecord which I’ll include at the end of this post. - Hydrate method will determine if the property is nullable and whether the value in the corresponding column of the data record has a null value var isNullable = property.PropertyType.IsGenericType && property.PropertyType.GetGenericTypeDefinition() == typeof (Nullable<>); var isNull = dataRecord.IsDBNull(ordinal); var propertyType = property.PropertyType; . . .  - If Hydrate method determines the property is nullable it will determine the underlying type and set propertyType accordingly - Hydrate method will set the value of the property based upon the propertyType   That’s it!!!   The magic here is in a few places. First, you may have noticed the following: public abstract class SharedBase<T> where T : SharedBase<T> This says that SharedBase can be created with any type and that for each type it will have it’s own instance. This is important because of the static members within SharedBase. We want this behavior because we are caching the properties for each type. If we did not handle things in this way only 1 type could be cached at a time, or, we’d need to create a collection that allows us to cache the properties for each type = not very elegant.   Second, in the constructor for foo you may have noticed this (literally): public foo(IDataRecord record) {      Hydrate(record, this); } I wanted the code for auto-hydrating to be as simple as possible. At first I wasn’t quite sure how I could call Hydrate on SharedBase within an instance of the class and pass in the instance itself. Fortunately simply passing in “this” does the trick. I wasn’t sure it would work until I tried it out, and fortunately it did.   So, to actually use this feature when utilizing ADO.NET you’d do something like the following:        public List<foo> GetFoo(int? fooId)         {             List<foo> fooList;             const string uspName = "usp_GetFoo";             using (var conn = new SqlConnection(_dbConnection))             using (var cmd = new SqlCommand(uspName, conn))             {                 cmd.CommandType = CommandType.StoredProcedure;                 cmd.Parameters.Add(new SqlParameter("@FooID", SqlDbType.Int)                                        {Direction = ParameterDirection.Input, Value = fooId});                 conn.Open();                 using (var dr = cmd.ExecuteReader())                 {                     fooList= (from row in dr.Cast<DbDataRecord>()                                             select                                                 new foo(row)                                            ).ToList();                 }             }             return fooList;         }   Nice! Instead of having line after line manually assigning values from data record to an object you simply create a new instance and pass in the data record. Note that there are certainly instances where columns returned from stored procedure do not always match up with property names. In this scenario you can still use the above method and simply do your manual assignments afterward.

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  • ListBoxFor not populating with selected items

    - by user576838
    I've see this question asked a couple of other times, and I followed this after I tried things on my own with the MS music store demo to no avail, but I still can't get this to work. I've also noticed when I look at my MultiSelectList object in the viewmodel, it has the correct items in the selected items property, but if I expand the results view, it doesn't have any listboxitem with the selected value. What am I missing here? I feel like I'm taking crazy pills! Thanks in advance. model: public class Article { public int ArticleID { get; set; } public DateTime? DatePurchased { get; set; } public DateTime? LastWorn { get; set; } public string ThumbnailImg { get; set; } public string LargeImg { get; set; } public virtual List<Outfit> Outfits { get; set; } public virtual List<Tag> Tags { get; set; } } viewmodel: public class ArticleViewModel { public int ArticleID { get; set; } public List<Tag> Tags { get; set; } public MultiSelectList mslTags { get; set; } public virtual Article Article { get; set; } public ArticleViewModel(int ArticleID) { using (ctContext db = new ctContext()) { this.Article = db.Articles.Find(ArticleID); this.Tags = db.Tags.ToList(); this.mslTags = new MultiSelectList(this.Tags, "TagID", "Name", this.Article.Tags); } } } controller: public ActionResult Index() { ArticleIndexViewModel vm = new ArticleIndexViewModel(db); return View(vm); } view: @model ClosetTracker.ArticleViewModel @using (Html.BeginForm()) { <img id="bigImg" src="@Model.Article.ThumbnailImg" alt="img" /> @Html.HiddenFor(m => m.ArticleID); @Html.LabelFor(m => m.Article.Tags) @* @Html.ListBoxFor(m => m.Article.Tags, Model.Tags.Select(t => new SelectListItem { Text = t.Name, Value = t.TagID.ToString() }), new { Multiple = "multiple" }) *@ @Html.ListBoxFor(m => m.Article.Tags, Model.mslTags); @Html.LabelFor(m => m.Article.LastWorn) @Html.TextBoxFor(m => m.Article.LastWorn, new { @class = "datepicker" }) @Html.LabelFor(m => m.Article.DatePurchased) @Html.TextBoxFor(m => m.Article.DatePurchased, new { @class = "datepicker" }) <p> <input type="submit" value="Save" /> </p> } EDITED Ok, I changed around the constructor of the MultiSelectList to have a list of TagID in the selected value arg instead of a list of Tag objects. This shows the correct tags as selected in the results view when I watch the mslTags object in debug mode. However, it still isn't rendering correctly to the page. public class ArticleViewModel { public int ArticleID { get; set; } public List<Tag> Tags { get; set; } public MultiSelectList mslTags { get; set; } public virtual Article Article { get; set; } public ArticleViewModel(int ArticleID) { using (ctContext db = new ctContext()) { this.Article = db.Articles.Find(ArticleID); this.Tags = db.Tags.ToList(); this.mslTags = new MultiSelectList(this.Tags, "TagID", "Name", this.Article.Tags.Select(t => t.TagID).ToList()); } } }

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  • How to get XML into a Dictionary with an Expression?

    - by DaveDev
    I have the following XML: <PerformancePanel page="PerformancePanel.ascx" title=""> <FundGroup heading="Net Life Managed Funds"> <fund id="17" countryid="N0" index="24103723" /> <fund id="81" countryid="N0" index="24103723" /> <fund id="127" countryid="N0" index="24103722" /> <fund id="345" countryid="N0" index="24103723" /> <fund id="346" countryid="N0" index="24103723" /> </FundGroup> <FundGroup heading="Net Life Specialist Funds"> <fund id="110" countryid="N0" index="24103717" /> <fund id="150" countryid="N0" index="24103719" /> <fund id="119" countryid="N0" index="24103720" /> <fund id="115" countryid="N0" index="24103727" /> <fund id="141" countryid="N0" index="24103711" /> <fund id="137" countryid="N0" /> <fund id="146" countryid="N0" /> <fund id="133" countryid="N0" /> <fund id="90" countryid="N0" /> <fund id="104" countryid="N0" /> <fund id="96" countryid="N0" /> </FundGroup> </PerformancePanel> I can get the data into an anonymous object as follows: var offlineFactsheet = new { PerformancePanels = (from panel in doc.Elements("PerformancePanel") select new PerformancePanel { PerformanceFunds = (from fg in panel.Elements("FundGroup") select new { Heading = (fg.Attribute("heading") == null) ? "" : (string)fg.Attribute("heading"), Funds = (from fund in fg.Elements("fund") select new Fund { FundId = (int)fund.Attribute("id"), CountryId = (string)fund.Attribute("countryid"), FundIndex = (fund.Attribute("index") == null) ? null : new Index { Id = (int)fund.Attribute("index") }, FundNameAppend = (fund.Attribute("append") == null) ? "" : (string)fund.Attribute("append") }).ToList() }).ToDictionary(xx => xx.Heading, xx => xx.Funds)}; I'm trying to change my code such that I can assign the dictionary directly to a property of the class I'm working in, as described in this question. I'd like to have a Dictionary() where each header text is the key to the list of funds under it. I'm having difficulty applying the example in the linked question because that only returns a string, and this needs to return the dictionary. This is the point that I got to before it occurred to me that I'm lost!!!: this.PerformancePanels = doc.Elements("PerformancePanel").Select(e => { var control = (PerformancePanel)LoadControl(this.OfflineFactsheetPath + (string)e.Attribute("page")); control.PerformanceFunds = e.Elements("FundGroup").Select(f => { List<Fund> funds = (from fund in e.Elements("fund") select new Fund { FundId = (int)fund.Attribute("id"), CountryId = (string)fund.Attribute("countryid"), FundIndex = (fund.Attribute("index") == null) ? null : new Index { Id = (int)fund.Attribute("index") }, FundNameAppend = (fund.Attribute("append") == null) ? "" : (string)fund.Attribute("append") }).ToList(); string heading = (e.Attribute("heading") == null) ? "" : (string)e.Attribute("heading"); }).ToDictionary(xx => heading, xx => Funds); return control; }).ToList(); Could someone point me in the right direction please? I'm not even sure if 'Expression' is the right terminology. Could someone fill me in on that too? Thanks.

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  • NHibernate 3.0 and FluentNHibernate, how to get up and running&hellip;.

    - by DesigningCode
    First up. Its actually really easy. I’m not very religious about my DB tech, I don’t really care, I just want something that works.  So I’m happy to consider all options if they provide an advantage, and recently I was considering jumping from NHibernate to EF 4.0.  However before ditching NHibernate and jumping to EF 4.0 I thought I should try the head version of NHibernates trunk and the Head version of FluentNHibernate. I currently have a “Repository / Unit of Work” Framework built up around these two techs.  All up it makes my life pretty simple for dealing with databases.   The problem is the current release of NHibernate + the Linq provider wasn’t too hot for our purposes.  Especially trying to plug it into older VB.NET code.   The Linq provider spat the dummy with VB.NET lambdas.  Mainly because in C# Query().Where(l => l.Name.Contains("x") || l.Name.Contains("y")).ToList(); is not the same as the VB.NET Query().Where(Function(l) l.Name.Contains("x") Or l.Name.Contains("y")).ToList VB.NET seems to spit out … well…. something different :-) so anyways… Compiling your own version of NHibernate and FluentNHibernate.  It’s actually pretty easy! First you’ll need to install tortisesvn NAnt and Git if you don’t already have them.  NHibernate first step, get the subversion trunk https://nhibernate.svn.sourceforge.net/svnroot/nhibernate/trunk/ into a directory somewhere.  eg \thirdparty\nhibernate Then use NAnt to build it.   (if you open the .sln it will show errors in that  AssemblyInfo.cs doesn’t exist ) to build it, there is a .txt document with sample command line build instructions,  I simply used :- NAnt -D:project.config=release clean build >output-release-build.log *wait* *wait* *wait* and ta da, you will have a bin directory with all the release dlls. FluentNHibernate This was pretty simple. there’s instructions here :- http://wiki.fluentnhibernate.org/Getting_started#Installation basically, with git, create a directory, and you issue the command git clone git://github.com/jagregory/fluent-nhibernate.git and wait, and soon enough you have the source. Now, from the bin directory that NHibernate spit out, take everything and dump it into the subdirectory “fluent-nhibernate\tools\NHibernate” Now, to build, you can use rake….which a ruby build system, however you can also just open the solution and build.   Which is what I did.  I had a few problems with the references which I simply re-added using the new ones.  Once built, I just took all the NHibnerate dlls, and the fluent ones and replaced my existing NHibernate / Fluent and killed off the old linq project. All I had to change is the places that used  .Linq<T>  and replace them with .Query<T>  (which was easy as I had wrapped it already to isolate my code from such changes) and hey presto, everything worked.  Even the VB.NET linq calls. I need to do some more testing as I’ve only done basic smoke tests, but its all looking pretty good, so for now, I will stick to NHibernate!

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  • ASP.NET MVC - dropdown list post handling problem

    - by ile
    I've had troubles for a few days already with handling form that contains dropdown list. I tried all that I've learned so far but nothing helps. This is my code: using System; using System.Collections.Generic; using System.Linq; using System.Web; using CMS; using CMS.Model; using System.ComponentModel.DataAnnotations; namespace Portal.Models { public class ArticleDisplay { public ArticleDisplay() { } public int CategoryID { set; get; } public string CategoryTitle { set; get; } public int ArticleID { set; get; } public string ArticleTitle { set; get; } public DateTime ArticleDate; public string ArticleContent { set; get; } } public class HomePageViewModel { public HomePageViewModel(IEnumerable<ArticleDisplay> summaries, Article article) { this.ArticleSummaries = summaries; this.NewArticle = article; } public IEnumerable<ArticleDisplay> ArticleSummaries { get; private set; } public Article NewArticle { get; private set; } } public class ArticleRepository { private DB db = new DB(); // // Query Methods public IQueryable<ArticleDisplay> FindAllArticles() { var result = from category in db.ArticleCategories join article in db.Articles on category.CategoryID equals article.CategoryID orderby article.Date descending select new ArticleDisplay { CategoryID = category.CategoryID, CategoryTitle = category.Title, ArticleID = article.ArticleID, ArticleTitle = article.Title, ArticleDate = article.Date, ArticleContent = article.Content }; return result; } public IQueryable<ArticleDisplay> FindTodayArticles() { var result = from category in db.ArticleCategories join article in db.Articles on category.CategoryID equals article.CategoryID where article.Date == DateTime.Today select new ArticleDisplay { CategoryID = category.CategoryID, CategoryTitle = category.Title, ArticleID = article.ArticleID, ArticleTitle = article.Title, ArticleDate = article.Date, ArticleContent = article.Content }; return result; } public Article GetArticle(int id) { return db.Articles.SingleOrDefault(d => d.ArticleID == id); } public IQueryable<ArticleDisplay> DetailsArticle(int id) { var result = from category in db.ArticleCategories join article in db.Articles on category.CategoryID equals article.CategoryID where id == article.ArticleID select new ArticleDisplay { CategoryID = category.CategoryID, CategoryTitle = category.Title, ArticleID = article.ArticleID, ArticleTitle = article.Title, ArticleDate = article.Date, ArticleContent = article.Content }; return result; } // // Insert/Delete Methods public void Add(Article article) { db.Articles.InsertOnSubmit(article); } public void Delete(Article article) { db.Articles.DeleteOnSubmit(article); } // // Persistence public void Save() { db.SubmitChanges(); } } } using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; using Portal.Models; using CMS.Model; namespace Portal.Areas.CMS.Controllers { public class ArticleController : Controller { ArticleRepository articleRepository = new ArticleRepository(); ArticleCategoryRepository articleCategoryRepository = new ArticleCategoryRepository(); // // GET: /Article/ public ActionResult Index() { ViewData["categories"] = new SelectList ( articleCategoryRepository.FindAllCategories().ToList(), "CategoryId", "Title" ); Article article = new Article() { Date = DateTime.Now, CategoryID = 1 }; HomePageViewModel homeData = new HomePageViewModel(articleRepository.FindAllArticles().ToList(), article); return View(homeData); } // // GET: /Article/Details/5 public ActionResult Details(int id) { var article = articleRepository.DetailsArticle(id).Single(); if (article == null) return View("NotFound"); return View(article); } // // GET: /Article/Create //public ActionResult Create() //{ // ViewData["categories"] = new SelectList // ( // articleCategoryRepository.FindAllCategories().ToList(), "CategoryId", "Title" // ); // Article article = new Article() // { // Date = DateTime.Now, // CategoryID = 1 // }; // return View(article); //} // // POST: /Article/Create [ValidateInput(false)] [AcceptVerbs(HttpVerbs.Post)] public ActionResult Create(Article article) { if (ModelState.IsValid) { try { // TODO: Add insert logic here articleRepository.Add(article); articleRepository.Save(); return RedirectToAction("Index"); } catch { return View(article); } } else { return View(article); } } // // GET: /Article/Edit/5 public ActionResult Edit(int id) { ViewData["categories"] = new SelectList ( articleCategoryRepository.FindAllCategories().ToList(), "CategoryId", "Title" ); var article = articleRepository.GetArticle(id); return View(article); } // // POST: /Article/Edit/5 [ValidateInput(false)] [AcceptVerbs(HttpVerbs.Post)] public ActionResult Edit(int id, FormCollection collection) { Article article = articleRepository.GetArticle(id); try { // TODO: Add update logic here UpdateModel(article, collection.ToValueProvider()); articleRepository.Save(); return RedirectToAction("Details", new { id = article.ArticleID }); } catch { return View(article); } } // // HTTP GET: /Article/Delete/1 public ActionResult Delete(int id) { Article article = articleRepository.GetArticle(id); if (article == null) return View("NotFound"); else return View(article); } // // HTTP POST: /Article/Delete/1 [AcceptVerbs(HttpVerbs.Post)] public ActionResult Delete(int id, string confirmButton) { Article article = articleRepository.GetArticle(id); if (article == null) return View("NotFound"); articleRepository.Delete(article); articleRepository.Save(); return View("Deleted"); } [ValidateInput(false)] public ActionResult UpdateSettings(int id, string value, string field) { // This highly-specific example is from the original coder's blog system, // but you can substitute your own code here. I assume you can pick out // which text field it is from the id. Article article = articleRepository.GetArticle(id); if (article == null) return Content("Error"); if (field == "Title") { article.Title = value; UpdateModel(article, new[] { "Title" }); articleRepository.Save(); } if (field == "Content") { article.Content = value; UpdateModel(article, new[] { "Content" }); articleRepository.Save(); } if (field == "Date") { article.Date = Convert.ToDateTime(value); UpdateModel(article, new[] { "Date" }); articleRepository.Save(); } return Content(value); } } } and view: <%@ Page Title="" Language="C#" MasterPageFile="~/Areas/CMS/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<Portal.Models.HomePageViewModel>" %> <asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server"> Index </asp:Content> <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> <div class="naslov_poglavlja_main">Articles Administration</div> <%= Html.ValidationSummary("Create was unsuccessful. Please correct the errors and try again.") %> <% using (Html.BeginForm("Create","Article")) {%> <div class="news_forma"> <label for="Title" class="news">Title:</label> <%= Html.TextBox("Title", "", new { @class = "news" })%> <%= Html.ValidationMessage("Title", "*") %> <label for="Content" class="news">Content:</label> <div class="textarea_okvir"> <%= Html.TextArea("Content", "", new { @class = "news" })%> <%= Html.ValidationMessage("Content", "*")%> </div> <label for="CategoryID" class="news">Category:</label> <%= Html.DropDownList("CategoryId", (IEnumerable<SelectListItem>)ViewData["categories"], new { @class = "news" })%> <p> <input type="submit" value="Publish" class="form_submit" /> </p> </div> <% } %> <div class="naslov_poglavlja_main"><%= Html.ActionLink("Write new article...", "Create") %></div> <div id="articles"> <% foreach (var item in Model.ArticleSummaries) { %> <div> <div class="naslov_vijesti" id="<%= item.ArticleID %>"><%= Html.Encode(item.ArticleTitle) %></div> <div class="okvir_vijesti"> <div class="sadrzaj_vijesti" id="<%= item.ArticleID %>"><%= item.ArticleContent %></div> <div class="datum_vijesti" id="<%= item.ArticleID %>"><%= Html.Encode(String.Format("{0:g}", item.ArticleDate)) %></div> <a class="news_delete" href="#" id="<%= item.ArticleID %>">Delete</a> </div> <div class="dno"></div> </div> <% } %> </div> </asp:Content> When trying to post new article I get following error: System.InvalidOperationException: The ViewData item that has the key 'CategoryId' is of type 'System.Int32' but must be of type 'IEnumerable'. I really don't know what to do cause I'm pretty new to .net and mvc Any help appreciated! Ile EDIT: I found where I made mistake. I didn't include date. If in view form I add this line I'm able to add article: <%=Html.Hidden("Date", String.Format("{0:g}", Model.NewArticle.Date)) %> But, if I enter wrong datetype or leave title and content empty then I get the same error. In this eample there is no need for date edit, but I will need it for some other forms and validation will be necessary. EDIT 2: Error happens when posting! Call stack: App_Web_of9beco9.dll!ASP.areas_cms_views_article_create_aspx.__RenderContent2(System.Web.UI.HtmlTextWriter __w = {System.Web.UI.HtmlTextWriter}, System.Web.UI.Control parameterContainer = {System.Web.UI.WebControls.ContentPlaceHolder}) Line 31 + 0x9f bytes C#

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  • C# PredicateBuilder Entities: The parameter 'f' was not bound in the specified LINQ to Entities quer

    - by Neothor
    I needed to build a dynamic filter and I wanted to keep using entities. Because of this reason I wanted to use the PredicateBuilder from albahari. I created the following code: var invoerDatums = PredicateBuilder.True<OnderzoeksVragen>(); var inner = PredicateBuilder.False<OnderzoeksVragen>(); foreach (var filter in set.RapportInvoerFilter.ToList()) { if(filter.IsDate) { var date = DateTime.Parse(filter.Waarde); invoerDatums = invoerDatums.Or(o => o.Van >= date && o.Tot <= date); } else { string temp = filter.Waarde; inner = inner.Or(o => o.OnderzoekType == temp); } } invoerDatums = invoerDatums.And(inner); var onderzoeksVragen = entities.OnderzoeksVragen .AsExpandable() .Where(invoerDatums) .ToList(); When I ran the code there was only 1 filter which wasn't a date filter. So only the inner predicate was filled. When the predicate was executed I got the following error. The parameter 'f' was not bound in the specified LINQ to Entities query expression. While searching for an answer I found the following page. But this is already implemented in the LINQKit. Does anyone else experienced this error and know how to solve it?

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  • Entity Framework query not returning correctly enumerated results.

    - by SkippyFire
    I have this really strange problem where my entity framework query isn't enumerating correctly. The SQL Server table I'm using has a table with a Sku field, and the column is "distinct". It isn't a key, but it doesn't contain any duplicate values. Using actual SQL with where, distinct and group by cluases I have confirmed this. However, when I do this: // Not good foreach(var product in dc.Products) or // Not good foreach(var product in dc.Products.ToList()) or // Not good foreach(var product in dc.Products.OrderBy(p => p.Sku)) the first two objects that are returned ARE THE SAME!!! The third item was technically the second item in the table, but then the fourth item was the first row from the table again!!! The only solution I have found is to use the Distinct extension method, which shouldn't really do anything in this situation: // Good foreach(var product in dc.Products.ToList().Distinct()) Another weird thing about this is that the count of the resulting queries is the same!!! So whether or not the resulting enumerable has the correct results or duplicates, I always get the number of rows in the actual table! (No I don't have a limit clause anywhere). What could possibly cause this!?!?!?

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  • LINQ to DataSet Dataclass assignment question

    - by Overhed
    Hi all, I'm working on a Silverlight project trying to access a database using LINQ To DataSet and then sending data over to Silverlight via .ASMX web service. I've defined my DataSet using the Server Explorer tool (dragging and dropping all the different tables that I'm interested in). The DataSet is able to access the server and database with no issues. Below is code from one of my Web Methods: public List<ClassSpecification> getSpecifications() { DataSet2TableAdapters.SpecificationTableAdapter Sta = new DataSet2TableAdapters.SpecificationTableAdapter(); return (from Spec in Sta.GetData().AsEnumerable() select new ClassSpecification() { Specification = Spec.Field<String>("Specification"), SpecificationType = Spec.Field<string>("SpecificationType"), StatusChange = Spec.Field<DateTime>("StatusChange"), Spec = Spec.Field<int>("Spec") }).ToList<ClassSpecification>(); } I created a "ClassSpecification" data class which is going to contain my data and it has all the table fields as properties. My question is, is there a quicker way of doing the assignment than what is shown here? There are actually about 10 more fields, and I would imagine that since my DataSet knows my table definition, that I would have a quicker way of doing the assignment than going field by field. I tried just "select new ClassSpecification()).ToList Any help would be greatly appreciated.

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  • kendo ui filtering the grid table, need some idea

    - by cool_spirit
    I want to filter the table by last name, but cant work, here is my code in controller public JsonResult Filtering() { HealthContext rc = new HealthContext(); var last = rc.Profiles.Select(lastt => new SelectListItem { Text = lastt.LastName, Value = lastt.Id.ToString() }).ToList(); return Json(last.ToList(), JsonRequestBehavior.AllowGet); } in view <script type="text/x-kendo-template" id="template"> <div class="toolbar"> <label class="category-label" for="Last name"> by last name:</label> <input type="search" id="LastName" style="width: 230px"></input> </div> </script> and also <script> $(document).ready(function() { $("#grid").kendoGrid({ dataSource: { transport: { read: { url: "/Profiles/GetJsonData", dataType: "json" } }, pageSize: 10, }, toolbar: kendo.template($("#template").html()), height: 250, filterable: true, sortable: true, pageable: true, defaultSorting: 'LastName ASC', columns: [{ field: "Id", filterable: false }, { field: "FirstName", title: "First Name", width: 100, }, { field: "LastName", title: "Last Name", width: 200 }, { field: "Gender", title: "Gender" } ] }); var dropDown = grid.find("#LastName").kendoDropDownList({ dataTextField: "LastName", dataValueField: "Id", autoBind: false, optionLabel: "All", dataSource: { severFiltering: true, transport: { read: { url: "/Profiles/Filtering", dataType: "json" } }, }, change: function() { var value = this.value(); if (value) { grid.data("kendoGrid").dataSource.filter({ field: "Id", operator: "eq", value: parseInt(value) }); } else { grid.data("kendoGrid").dataSource.filter({}); } } }); }); </script> so the problem is the drop down list is not show up as well as the value/ data, any idea guys?

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  • DataGridViewColumn.DataPropertyName Property

    - by Captain Comic
    Hi I have a DataGridView control and I want to populate it with data. I use DataSource property // dgvDealAsset is DataGridView private void DealAssetListControl_Load(object sender, EventArgs e) { dgvDealAssets.AutoGenerateColumns = false; dgvDealAssets.DataSource = DealAssetList.Instance.Values.ToList(); } Now problem number one. The class of my collection does not contain only simple types that I can map to columns using DataPropertyName. This is the class that is contained in collection. class MyClass { public String Name; MyOtherClass otherclass; } class MyOtherClass { public String Name; } Now I am binding properties of MyClass to columns col1.DataPropertyName = "Name" // Ok col2.DataPropertyName = "otherclass" // Not OK - I will have empty cell The problem is that I want to display otherclass.Name field. But if I try to write col2.DataPropertyName = "otherclass.Name" I get empty cell. I tried to manually set the column private void DealAssetListControl_Load(object sender, EventArgs e) { dgvDealAssets.AutoGenerateColumns = false; dgvDealAssets.DataSource = DealAssetList.Instance.Values.ToList(); // iterate through rows and set the column manually foreach (DataGridViewRow row in dgvDealAssets.Rows) { row.Cells["Column2"].Value = ((DealAsset)row.DataBoundItem).otherclass.Name; } But this foreach cycle takes about minute to complete (2k elements). How to solve this problem?

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  • Querying a self referencing join with NHibernate Linq

    - by Ben
    In my application I have a Category domain object. Category has a property Parent (of type category). So in my NHibernate mapping I have: <many-to-one name="Parent" column="ParentID"/> Before I switched to NHibernate I had the ParentId property on my domain model (mapped to the corresponding database column). This made it easy to query for say all top level categories (ParentID = 0): where(c => c.ParentId == 0) However, I have since removed the ParentId property from my domain model (because of NHibernate) so I now have to do the same query (using NHibernate.Linq) like so: public IList<Category> GetCategories(int parentId) { if (parentId == 0) return _catalogRepository.Categories.Where(x => x.Parent == null).ToList(); else return _catalogRepository.Categories.Where(x => x.Parent.Id == parentId).ToList(); } The real impact that I can see, is the sql generated. Instead of a simple 'select x,y,z from categories where parentid = 0' NHibernate generates a left outer join: SELECT this_.CategoryId as CategoryId4_1_, this_.ParentID as ParentID4_1_, this_.Name as Name4_1_, this_.Slug as Slug4_1_, parent1_.CategoryId as CategoryId4_0_, parent1_.ParentID as ParentID4_0_, parent1_.Name as Name4_0_, parent1_.Slug as Slug4_0_ FROM Categories this_ left outer join Categories parent1_ on this_.ParentID = parent1_.CategoryId WHERE this_.ParentID is null Which doesn't seems much less efficient that what I had before. Is there a better way of querying these self referencing joins as it's very tempting to drop the ParentID back onto my domain model for this reason. Thanks, Ben

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  • Serializing Complex ViewModel with Json.Net Destabilization Error on Latest Version

    - by dreadlocks1221
    I just added the latest Version of JSON.Net and I get the System.Security.VerificationException: Operation could destabilize the runtime error when trying to use a controller (while running the application). I read in other posts that this issue should have been fixed in release 6 but I still have the problem. I even added *Newtonsoft.* to the ignore modules in the intellitrace options, which seems to have suppressed the error, but the post will just run forever and not return anything. Any help I can get would be greatly appreciated. [HttpPost] public string GetComments(int ShowID, int Page) { int PageSize = 10; UserRepository UserRepo = new UserRepository(); ShowCommentViewModel viewModel = new ShowCommentViewModel(); IQueryable<Comment> CommentQuery = showRepository.GetShowComments(ShowID); var paginatedComments = new PaginatedList<Comment>(CommentQuery, Page, PageSize); viewModel.Comments = new List<CommentViewModel>(); foreach (Comment comment in CommentQuery.Take(10).ToList()) { CommentViewModel CommentModel = new CommentViewModel { Comment = comment, PostedBy = UserRepo.GetUserProfile(comment.UserID) }; IQueryable<Comment> ReplyQuery = showRepository.GetShowCommentReplies(comment.CommentID); int ReplyPage = 0; var paginatedReplies = new PaginatedList<Comment>(ReplyQuery, ReplyPage, 3); CommentModel.Replies = new List<ReplyModel>(); foreach (Comment reply in ReplyQuery.Take(3).ToList()) { ReplyModel rModel = new ReplyModel { Reply = reply, PostedBy = UserRepo.GetUserProfile(reply.UserID) }; CommentModel.Replies.Add(rModel); } CommentModel.RepliesNextPage = paginatedReplies.HasNextPage; CommentModel.RepliesPeviousPage = paginatedReplies.HasPreviousPage; CommentModel.RepliesTotalPages = paginatedReplies.TotalPages; CommentModel.RepliesPageIndex = paginatedReplies.PageIndex; CommentModel.RepliesTotalCount = paginatedReplies.TotalCount; viewModel.Comments.Add(CommentModel); } viewModel.CommentsNextPage = paginatedComments.HasNextPage; viewModel.CommentsPeviousPage = paginatedComments.HasPreviousPage; viewModel.CommentsTotalPages = paginatedComments.TotalPages; viewModel.CommentsPageIndex = paginatedComments.PageIndex; viewModel.CommentsTotalCount = paginatedComments.TotalCount; return JsonConvert.SerializeObject(viewModel, Formatting.Indented); }

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  • Collection is empty when it arrives on the client

    - by digiduck
    One of my entities has an EntitySet< property with [Composition], [Include] and [Association] attributes. I populate this collection in my domain service but when I check its contents when it is received on the client, the collection is empty. I am using Silverlight 4 RTM as well as RIA Services 1.0 RTM. Any ideas what I am doing wrong? Here is the code on my service side: public class RegionDto { public RegionDto() { Cities = new EntitySet<CityDto>(); } [Key] public int Id { get; set; } public string Name { get; set; } [Include] [Composition] [Association("RegionDto_CityDto", "Id", "RegionId")] public EntitySet<CityDto> Cities { get; set; } } public class CityDto { [Key] public int Id { get; set; } public int RegionId { get; set; } public string Name { get; set; } } [EnableClientAccess()] public class RegionDomainService : LinqToEntitiesDomainService<RegionEntities> { public IEnumerable<RegionDto> GetRegions() { var regions = (ObjectContext.Regions .Select(x => new RegionDto { Id = x.ID, Name = x.Name })).ToList(); foreach (var region in regions) { var cities = (ObjectContext.Cities .Where(x => x.RegionID == region.Id) .Select(x => new CityDto { Id = x.ID, Name = x.Name })).ToList(); foreach (var city in cities) { region.Cities.Add(city); } } // each region's Cities collection is populated at this point // however when the client receives it, the Cities collections are all empty return regions; } }

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  • Typecasting EnityObject

    - by AJ
    Hello, I'm new to C# and am stuck on the following. I have a Silverlight web service that uses LINQ to query a ADO.NET entity object. e.g.: [OperationContract] public List<Customer> GetData() { using (TestEntities ctx = new TestEntities()) { var data = from rec in ctx.Customer select rec; return data.ToList(); } } This works fine, but what I want to do is to make this more abstract. The first step would be to return a List<EntityObject> but this gives a compiler error, e.g.: [OperationContract] public List<EntityObject> GetData() { using (TestEntities ctx = new TestEntities()) { var data = from rec in ctx.Customer select rec; return data.ToList(); } } The error is: Error 1 Cannot implicitly convert type 'System.Collections.Generic.List<SilverlightTest.Web.Customer>' to 'System.Collections.Generic.IEnumerable<System.Data.Objects.DataClasses.EntityObject>'. An explicit conversion exists (are you missing a cast?) What am i doing wrong? Thanks, AJ

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  • Functional way to get a matrix from text

    - by Elazar Leibovich
    I'm trying to solve some Google Code Jam problems, where an input matrix is typically given in this form: 2 3 #matrix dimensions 1 2 3 4 5 6 7 8 9 # all 3 elements in the first row 2 3 4 5 6 7 8 9 0 # each element is composed of three integers where each element of the matrix is composed of, say, three integers. So this example should be converted to #!scala Array( Array(A(1,2,3),A(4,5,6),A(7,8,9), Array(A(2,3,4),A(5,6,7),A(8,9,0), ) An imperative solution would be of the form #!python input = """2 3 1 2 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 0 """ lines = input.split('\n') print lines[0] m,n = (int(x) for x in lines[0].split()) array = [] row = [] A = [] for line in lines[1:]: for elt in line.split(): A.append(elt) if len(A)== 3: row.append(A) A = [] array.append(row) row = [] from pprint import pprint pprint(array) A functional solution I've thought of is #!scala def splitList[A](l:List[A],i:Int):List[List[A]] = { if (l.isEmpty) return List[List[A]]() val (head,tail) = l.splitAt(i) return head :: splitList(tail,i) } def readMatrix(src:Iterator[String]):Array[Array[TrafficLight]] = { val Array(x,y) = src.next.split(" +").map(_.trim.toInt) val mat = src.take(x).toList.map(_.split(" "). map(_.trim.toInt)). map(a => splitList(a.toList,3). map(b => TrafficLight(b(0),b(1),b(2)) ).toArray ).toArray return mat } But I really feel it's the wrong way to go because: I'm using the functional List structure for each line, and then convert it to an array. The whole code seems much less efficeint I find it longer less elegant and much less readable than the python solution. It is harder to which of the map functions operates on what, as they all use the same semantics. What is the right functional way to do that?

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  • "<" operator error

    - by Nona Urbiz
    Why is the ( i < UniqueWords.Count ) expression valid in the for loop, but returns "CS0019 Operator '<' cannot be applied to operands of type 'int' and 'method group'" error when placed in my if? They are both string arrays, previously declared. for (int i = 0;i<UniqueWords.Count;i++){ Occurrences[i] = Words.Where(x => x.Equals(UniqueWords[i])).Count(); Keywords[i] = UniqueWords[i]; if (i<UniqueURLs.Count) {rURLs[i] = UniqueURLs[i];} } EDITED to add declarations: List<string> Words = new List<string>(); List<string> URLs = new List<string>(); //elements added like so. . . . Words.Add (referringWords); //these are strings URLs.Add (referringURL); UniqueWords = Words.Distinct().ToList(); UniqueURLs = URLs.Distinct().ToList(); SOLVED. thank you, parentheses were needed for method .Count() I still do not fully understand why they are not always necessary. Jon Skeet, thanks, I guess I don't understand what exactly the declarations are either then? You wanted the actual values assigned? They are pulled from an external source, but are strings. I get it! Thanks. (the ()'s at least.)

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  • Generic list typecasting problem

    - by AJ
    Hello, I'm new to C# and am stuck on the following. I have a Silverlight web service that uses LINQ to query a ADO.NET entity object. e.g.: [OperationContract] public List<Customer> GetData() { using (TestEntities ctx = new TestEntities()) { var data = from rec in ctx.Customer select rec; return data.ToList(); } } This works fine, but what I want to do is to make this more abstract. The first step would be to return a List<EntityObject> but this gives a compiler error, e.g.: [OperationContract] public List<EntityObject> GetData() { using (TestEntities ctx = new TestEntities()) { var data = from rec in ctx.Customer select rec; return data.ToList(); } } The error is: Error 1 Cannot implicitly convert type 'System.Collections.Generic.List<SilverlightTest.Web.Customer>' to 'System.Collections.Generic.IEnumerable<System.Data.Objects.DataClasses.EntityObject>'. An explicit conversion exists (are you missing a cast?) What am i doing wrong? Thanks, AJ

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  • Odd Linq behavior with IList / IEnumerable

    - by Aren B
    I've got the following code: public IList<IProductViewModel> ChildProducts { get; set; } public IList<IProductViewModel> GiftItems { get; set; } public IList<IProductViewModel> PromoItems { get; set; } public IList<IProductViewModel> NonGiftItems { get { return NonPromoItems.Except(GiftItems, new ProductViewModelComparer()).ToList(); } } public IList<IProductViewModel> NonPromoItems { get { return ChildProducts.Where(p => !p.IsPromotion).ToList(); } } So basically, NonPromoItems is (ChildProducts - PromoItems) and NonGiftItems is (NonPromoItems - GiftItems) However When: ChildProducts = IEnumerable<IProductViewModel>[6] PromoItems = IEnumerable<IProductViewModel>[1] where item matches 1 item in ChildProducts GiftItems = IEnumerable<IProductViewModel>[0] My Result is NonPromoItems = IEnumerable<IProductViewModel>[5] This is Correct NonGiftItems = IEnumerable<IProductViewModel>[4] This is Incorrect Somehow an Except(...) is removing an item when given an empty list to subtract. Any ideas anyone?

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  • C# - Class Type as Parameter in methods

    - by Claudio
    Hi guys, I'm using SQLite.cs wrapper for helping me with the database and I have this method for create XML from a table, that is working fine. public void GenerateInvoiceXML(string filePath) { var invoices = app.db.Table<Invoice>().ToList(); XmlSerializer serializer = new XmlSerializer( typeof(List<Invoice>) ); TextWriter writer = new StreamWriter(filePath); serializer.Serialize(writer,invoices); writer.Close(); } All tables that I have are defined like this: [Serializable] public class Invoice { [PrimaryKey, AutoIncrement] public int Id { get; set; } public string Supplier {get; set;} public string Date {get; set;} public string PaymentMethod {get; set;} public string Notes {get; set;} public Invoice(int newID) { Id = newID; } public Invoice() { } } But I want to change this method for something like this: public void GenerateInvoiceXML(string filePath, Type table) { var dataForXML = app.db.Table<table>().ToList(); XmlSerializer serializer = new XmlSerializer( typeof(List<table>) ); TextWriter writer = new StreamWriter(filePath); serializer.Serialize(writer,dataForXML); writer.Close(); } Does anybody have an idea how to do it? Kind Regards, Claudio

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  • Can't return a List from a Compiled Query.

    - by Andrew
    I was speeding up my app by using compiled queries for queries which were getting hit over and over. I tried to implement it like this: Function Select(ByVal fk_id As Integer) As List(SomeEntity) Using db As New DataContext() db.ObjectTrackingEnabled = False Return CompiledSelect(db, fk_id) End Using End Function Shared CompiledSelect As Func(Of DataContext, Integer, List(Of SomeEntity)) = _ CompiledQuery.Compile(Function(db As DataContext, fk_id As Integer) _ (From u In db.SomeEntities _ Where u.SomeLinkedEntity.ID = fk_id _ Select u).ToList()) This did not work and I got this error message: Type : System.ArgumentNullException, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 Message : Value cannot be null. Parameter name: value However, when I changed my compiled query to return IQueryable instead of List like so: Function Select(ByVal fk_id As Integer) As List(SomeEntity) Using db As New DataContext() db.ObjectTrackingEnabled = False Return CompiledSelect(db, fk_id).ToList() End Using End Function Shared CompiledSelect As Func(Of DataContext, Integer, IQueryable(Of SomeEntity)) = _ CompiledQuery.Compile(Function(db As DataContext, fk_id As Integer) _ From u In db.SomeEntities _ Where u.SomeLinkedEntity.ID = fk_id _ Select u) It worked fine. Can anyone shed any light as to why this is? BTW, compiled queries rock! They sped up my app by a factor of 2.

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  • Entity Framework - Insert/Update new entity with child-entities

    - by Christina Mayers
    I have found many questions here on SO and articles all over the internet but none really tackled my problem. My model looks like this (I striped all non essential Properties): Everyday or so "Play" gets updated (via a XML-file containing the information). internal Play ParsePlayInfo(XDocument doc) { Play play = (from p in doc.Descendants("Play") select new Play { Theatre = new Theatre() { //Properties }, //Properties LastUpdate = DateTime.Now }).SingleOrDefault(); var actors = (from a in doc.XPathSelectElement(".//Play//Actors").Nodes() select new Lecturer() { //Properties }); var parts = (from p in doc.XPathSelectElement(".//Play//Parts").Nodes() select new Part() { //Properties }).ToList(); foreach (var item in parts) { play.Parts.Add(item); } var reviews = (from r in doc.XPathSelectElement(".//Play//Reviews").Nodes() select new Review { //Properties }).ToList(); for (int i = 0; i < reviews.Count(); i++) { PlayReviews pR = new PlayReviews() { Review = reviews[i], Play = play, //Properties }; play.PlayReviews.Add(pR); } return play; } If I add this "play" via Add() every Childobject of Play will be inserted - regardless if some exist already. Since I need to update existing entries I have to do something about that. As far as I can tell I have the following options: add/update the child entities in my PlayRepositories Add-Method restructure and rewrite ParsePlayInfo() so that get all the child entities first, add or update them and then create a new Play. The only problem I have here is that I wanted ParsePlayInfo() to be persistence ignorant, I could work around this by creating multiple parse methods (eg ParseActors() ) and assign them to play in my controller (I'm using ASP.net MVC) after everything was parsed and added Currently I am implementing option 1 - but it feels wrong. I'd appreciate it if someone could guide me in the right direction on this one.

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  • Linq is returning too many results when joined

    - by KallDrexx
    In my schema I have two database tables. relationships and relationship_memberships. I am attempting to retrieve all the entries from the relationship table that have a specific member in it, thus having to join it with the relationship_memberships table. I have the following method in my business object: public IList<DBMappings.relationships> GetRelationshipsByObjectId(int objId) { var results = from r in _context.Repository<DBMappings.relationships>() join m in _context.Repository<DBMappings.relationship_memberships>() on r.rel_id equals m.rel_id where m.obj_id == objId select r; return results.ToList<DBMappings.relationships>(); } _Context is my generic repository using code based on the code outlined here. The problem is I have 3 records in the relationships table, and 3 records in the memberships table, each membership tied to a different relationship. 2 membership records have an obj_id value of 2 and the other is 3. I am trying to retrieve a list of all relationships related to object #2. When this linq runs, _context.Repository<DBMappings.relationships>() returns the correct 3 records and _context.Repository<DBMappings.relationship_memberships>() returns 3 records. However, when the results.ToList() executes, the resulting list has 2 issues: 1) The resulting list contains 6 records, all of type DBMappings.relationships(). Upon further inspection there are 2 for each real relationship record, both are an exact copy of each other. 2) All relationships are returned, even if m.obj_id == 3, even though objId variable is correctly passed in as 2. Can anyone see what's going on because I've spent 2 days looking at this code and I am unable to understand what is wrong. I have joins in other linq queries that seem to be working great, and my unit tests show that they are still working, so I must be doing something wrong with this. It seems like I need an extra pair of eyes on this one :)

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