Search Results

Search found 266 results on 11 pages for 'nullreferenceexception'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 3/11 | < Previous Page | 1 2 3 4 5 6 7 8 9 10 11  | Next Page >

  • How to check for a null object reference when validating forms in MVC

    - by quakkels
    Hello SO, I'm experimenting with validating forms in the asp.net MVC framework. I'm focusing on server side validation for the time being. I've come across an error that I'm not sure how to rectify. System.NullReferenceException: Object reference not set to an instance of an object. The code that throws the error is: [AcceptVerbs(HttpVerbs.Post)] public ActionResult Create([Bind(Exclude="ID")] MembersCreate mc ) { mc.Modules = ModuleListDataContext.GetModuleList(); ViewData.Model = mc; //Validation using ModelState // // //line below errors when form field is empty // if ((string)mc.Member.Username.Trim() == "") ModelState.AddModelError("Member.Username", "Username is required."); if (!ModelState.IsValid) return View(); try { // TODO: Add insert logic here return RedirectToAction("Index","Home"); } catch { return View(); } } When I put spaces in the field it performs exactly as i want, but if I leave the field blank and press submit I get the error. What's the best way to avoid this error and still validate blank form fields? Thanks all -

    Read the article

  • ASP.NET C# DataList FindControl & Header/Footer template causes error

    - by m3n
    Hello, whenever I use the Header or Footer template of DataList, FindControl is unable to find a label part of the DataList, and throws a NullReferenceException. My SQLDataSource and DataList (no Header and Footer template - works): <asp:SqlDataSource ID="sdsMinaKop" runat="server" ConnectionString="<%$ ConnectionStrings:dbCSMinaKop %>" SelectCommand="SELECT kopare_id, bok_id, bok_titel, bok_pris, kop_id FROM kop WHERE kopare_id = @UserName" onselecting="sdsMinaKop_Selecting"> <SelectParameters> <asp:Parameter DefaultValue="admin" Name="UserName" /> </SelectParameters> <asp:SelectParameters> <asp:Parameter Name="UserName" Type="String" /> </asp:SelectParameters> </asp:SqlDataSource> <asp:DataList ID="DataList1" runat="server" DataKeyField="kop_id" DataSourceID="sdsMinaKop" onitemdatabound="DataList1_ItemDataBound" RepeatLayout="Table"> <ItemTemplate> <tr> <td><asp:Label ID="bok_titelLabel" runat="server" Text='<%# Eval("bok_titel") %>' /></td> <td><asp:Label ID="bok_prisLabel" runat="server" Text='<%# Eval("bok_pris") %>' /> kr</td> <td><a href="avbestall.aspx?id='<%# Eval("kop_id") %>'" />[X]</a></td> </tr> </ItemTemplate> <ItemStyle Wrap="False" /> </asp:DataList> With Header & Footer template - does not work. <asp:DataList ID="DataList1" runat="server" DataKeyField="kop_id" DataSourceID="sdsMinaKop" onitemdatabound="DataList1_ItemDataBound" RepeatLayout="Table"> <ItemTemplate> <tr> <td><asp:Label ID="bok_titelLabel" runat="server" Text='<%# Eval("bok_titel") %>' /></td> <td><asp:Label ID="bok_prisLabel" runat="server" Text='<%# Eval("bok_pris") %>' /> kr</td> <td><a href="avbestall.aspx?id='<%# Eval("kop_id") %>'" />[X]</a></td> </tr> </ItemTemplate> <ItemStyle Wrap="False" /> <HeaderTemplate> a </HeaderTemplate> <FooterTemplate> a </FooterTemplate> </asp:DataList> Selecting event: protected void DataList1_ItemDataBound(object sender, DataListItemEventArgs e) { Label pris = (Label)e.Item.FindControl("bok_prisLabel"); LabelTotalt.Text = (Convert.ToDouble(LabelTotalt.Text) + Convert.ToDouble(pris.Text)).ToString(); } Why would this happen? Thanks

    Read the article

  • Duplex Contract GetCallbackChannel always returns a null-instance

    - by Yaroslav
    Hi! Here is the server code: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.ServiceModel; using System.Runtime.Serialization; using System.ServiceModel.Description; namespace Console_Chat { [ServiceContract(SessionMode = SessionMode.Required, CallbackContract = typeof(IMyCallbackContract))] public interface IMyService { [OperationContract(IsOneWay = true)] void NewMessageToServer(string msg); [OperationContract(IsOneWay = false)] bool ServerIsResponsible(); } [ServiceContract] public interface IMyCallbackContract { [OperationContract(IsOneWay = true)] void NewMessageToClient(string msg); [OperationContract(IsOneWay = true)] void ClientIsResponsible(); } [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerSession)] public class MyService : IMyService { public IMyCallbackContract callback = null; /* { get { return OperationContext.Current.GetCallbackChannel<IMyCallbackContract>(); } } */ public MyService() { callback = OperationContext.Current.GetCallbackChannel<IMyCallbackContract>(); } public void NewMessageToServer(string msg) { Console.WriteLine(msg); } public void NewMessageToClient( string msg) { callback.NewMessageToClient(msg); } public bool ServerIsResponsible() { return true; } } class Server { static void Main(string[] args) { String msg = "none"; ServiceMetadataBehavior behavior = new ServiceMetadataBehavior(); ServiceHost serviceHost = new ServiceHost( typeof(MyService), new Uri("http://localhost:8080/")); serviceHost.Description.Behaviors.Add(behavior); serviceHost.AddServiceEndpoint( typeof(IMetadataExchange), MetadataExchangeBindings.CreateMexHttpBinding(), "mex"); serviceHost.AddServiceEndpoint( typeof(IMyService), new WSDualHttpBinding(), "ServiceEndpoint" ); serviceHost.Open(); Console.WriteLine("Server is up and running"); MyService server = new MyService(); server.NewMessageToClient("Hey client!"); /* do { msg = Console.ReadLine(); // callback.NewMessageToClient(msg); } while (msg != "ex"); */ Console.ReadLine(); } } } Here is the client's: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.ServiceModel; using System.Runtime.Serialization; using System.ServiceModel.Description; using Console_Chat_Client.MyHTTPServiceReference; namespace Console_Chat_Client { [ServiceContract(SessionMode = SessionMode.Required, CallbackContract = typeof(IMyCallbackContract))] public interface IMyService { [OperationContract(IsOneWay = true)] void NewMessageToServer(string msg); [OperationContract(IsOneWay = false)] bool ServerIsResponsible(); } [ServiceContract] public interface IMyCallbackContract { [OperationContract(IsOneWay = true)] void NewMessageToClient(string msg); [OperationContract(IsOneWay = true)] void ClientIsResponsible(); } public class MyCallback : Console_Chat_Client.MyHTTPServiceReference.IMyServiceCallback { static InstanceContext ctx = new InstanceContext(new MyCallback()); static MyServiceClient client = new MyServiceClient(ctx); public void NewMessageToClient(string msg) { Console.WriteLine(msg); } public void ClientIsResponsible() { } class Client { static void Main(string[] args) { String msg = "none"; client.NewMessageToServer(String.Format("Hello server!")); do { msg = Console.ReadLine(); if (msg != "ex") client.NewMessageToServer(msg); else client.NewMessageToServer(String.Format("Client terminated")); } while (msg != "ex"); } } } } callback = OperationContext.Current.GetCallbackChannel(); This line constanly throws a NullReferenceException, what's the problem? Thanks!

    Read the article

  • null reference expction in the code

    - by LifeH2O
    I am getting NullReferenceException error on "_attr.Append(xmlNode.Attributes["name"]);". namespace SMAS { class Profiles { private XmlTextReader _profReader; private XmlDocument _profDoc; private const string Url = "http://localhost/teamprofiles.xml"; private const string XPath = "/teams/team-profile"; public XmlNodeList Teams{ get; private set; } private XmlAttributeCollection _attr; public ArrayList Team { get; private set; } public void GetTeams() { _profReader = new XmlTextReader(Url); _profDoc = new XmlDocument(); _profDoc.Load(_profReader); Teams = _profDoc.SelectNodes(XPath); foreach (XmlNode xmlNode in Teams) { _attr.Append(xmlNode.Attributes["name"]); } } } } the teamprofiles.xml file looks like <teams> <team-profile name="Australia"> <stats type="Test"> <span>1877-2010</span> <matches>721</matches> <won>339</won> <lost>186</lost> <tied>2</tied> <draw>194</draw> <percentage>47.01</percentage> </stats> <stats type="Twenty20"> <span>2005-2010</span> <matches>32</matches> <won>18</won> <lost>12</lost> <tied>1</tied> <draw>1</draw> <percentage>59.67</percentage> </stats> </team-profile> <team-profile name="Bangladesh"> <stats type="Test"> <span>2000-2010</span> <matches>66</matches> <won>3</won> <lost>57</lost> <tied>0</tied> <draw>6</draw> <percentage>4.54</percentage> </stats> </team-profile> </teams> I am trying to extract names of all teams in an ArrayList. Then i'll extract all stats of all teams and display them in my application. Can you please help me about that null reference exception?

    Read the article

  • null reference exception in the code

    - by LifeH2O
    I am getting NullReferenceException error on "_attr.Append(xmlNode.Attributes["name"]);". namespace SMAS { class Profiles { private XmlTextReader _profReader; private XmlDocument _profDoc; private const string Url = "http://localhost/teamprofiles.xml"; private const string XPath = "/teams/team-profile"; public XmlNodeList Teams{ get; private set; } private XmlAttributeCollection _attr; public ArrayList Team { get; private set; } public void GetTeams() { _profReader = new XmlTextReader(Url); _profDoc = new XmlDocument(); _profDoc.Load(_profReader); Teams = _profDoc.SelectNodes(XPath); foreach (XmlNode xmlNode in Teams) { _attr.Append(xmlNode.Attributes["name"]); } } } } the teamprofiles.xml file looks like <teams> <team-profile name="Australia"> <stats type="Test"> <span>1877-2010</span> <matches>721</matches> <won>339</won> <lost>186</lost> <tied>2</tied> <draw>194</draw> <percentage>47.01</percentage> </stats> <stats type="Twenty20"> <span>2005-2010</span> <matches>32</matches> <won>18</won> <lost>12</lost> <tied>1</tied> <draw>1</draw> <percentage>59.67</percentage> </stats> </team-profile> <team-profile name="Bangladesh"> <stats type="Test"> <span>2000-2010</span> <matches>66</matches> <won>3</won> <lost>57</lost> <tied>0</tied> <draw>6</draw> <percentage>4.54</percentage> </stats> </team-profile> </teams> I am trying to extract names of all teams in an ArrayList. Then i'll extract all stats of all teams and display them in my application. Can you please help me about that null reference exception?

    Read the article

  • ASP.NET MVC: null reference exception using HtmlHelper.TextBox and custom model binder

    - by mr.nicksta
    I have written a class which implements IModelBinder (see below). This class handles a form which has 3 inputs each representing parts of a date value (day, month, year). I have also written a corresponding HtmlHelper extension method to print out three fields on the form. When the day, month, year inputs are given values which can be parsed, but a seperate value fails validation, all is fine - the fields are repopulated and the page served to the user as expected. however when an invalid values are supplied and a DateTime cannot be parsed, i return an arbitrary DateTime so that the fields will be repopulated when returned to the user. I read up on similar problems people have had and they all seemed to be due to lack of calling SetModelValue(). I wasn't doing this, but even after adding the problem has not been resolved. public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) { string modelName = bindingContext.ModelName; string monthKey = modelName + ".Month"; string dayKey = modelName + ".Day"; string yearKey = modelName + ".Year"; //get values submitted on form string year = bindingContext.ValueProvider[yearKey].AttemptedValue; string month = bindingContext.ValueProvider[monthKey].AttemptedValue; string day = bindingContext.ValueProvider[dayKey].AttemptedValue; DateTime parsedDate; if (DateTime.TryParse(string.Format(DateFormat, year, month, day), out parsedDate)) return parsedDate; //could not parse date time report error, return current date bindingContext.ModelState.AddModelError(yearKey, ValidationErrorMessages.DateInvalid); //added this after reading similar problems, does not fix! bindingContext.ModelState.SetModelValue(modelName, bindingContext.ValueProvider[modelName]); return DateTime.Today; } the null reference exception is thrown when i attempt to create a textbox for the Year property of the date, but strangely not for Day or Month! Can anyone offer an explanation as to why this is? Thanks :-)

    Read the article

  • Error loading contents from a XML file into a dropdownlist

    - by Chaitanya
    private void BindCountry() { XmlDocument doc = new XmlDocument(); doc.Load(Server.MapPath("countries.xml")); foreach (XmlNode node in doc.SelectNodes("//country")) { usrlocationddl.Items.Add(new ListItem(node.InnerText, node.Attributes["codes"].InnerText)); //ddlCountry.Items.Add(new ListItem(node.InnerText, node.Attributes["code"].InnerText)); } } The above code am using for loading countries List from an xml file into a dropdown list. But while doing so am encountering a Null Reference error. Object reference not set to an instance of an object. Where in the code should I be changing, so that I can escape the error.

    Read the article

  • GetHashCode on null fields?

    - by Shimmy
    How do I deal with null fields in GetHashCode function? Module Module1 Sub Main() Dim c As New Contact Dim hash = c.GetHashCode End Sub Public Class Contact : Implements IEquatable(Of Contact) Public Name As String Public Address As String Public Overloads Function Equals(ByVal other As Contact) As Boolean _ Implements System.IEquatable(Of Contact).Equals Return Name = other.Name AndAlso Address = other.Address End Function Public Overrides Function Equals(ByVal obj As Object) As Boolean If ReferenceEquals(Me, obj) Then Return True If TypeOf obj Is Contact Then Return Equals(DirectCast(obj, Contact)) Else Return False End If End Function Public Overrides Function GetHashCode() As Integer Return Name.GetHashCode Xor Address.GetHashCode End Function End Class End Module

    Read the article

  • Why is my code returning a Null Object Refrence error when using WatIn?

    - by Fuzz Evans
    I keep getting a Null Object Refrence Error, but can't tell why. I have a CSV file that contains 100 urls. The file is read into an array called "lines". public partial class Form1 : System.Windows.Forms.Form { string[] lines; public Form1() ... private void ReadLinksIntoMemory() { //this reads the chosen csv file into our "lines" array //and splits on comma's and new lines to create new objects within the array using (StreamReader sr = new StreamReader(@"C:\temp.csv")) { //reads everything in our csv into 1 long line string fileContents = sr.ReadToEnd(); //splits the 1 long line read in into multiple objects of the lines array lines = fileContents.Split(new string[] { ",", Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries); sr.Dispose(); } } The next part is where I get the null object error. When I try to use WatIn to go to the first item in the lines array it says I'm referencing a null object. private void GoToEditLinks() { for (int i = 0; i < lines.Length; i++) { //go to each link sequentially myIE.GoTo(lines[i].ToString()); //sleep so we can make sure the page loads System.Threading.Thread.Sleep(5000); } } When I debug the code it says that the GoTo request calls lines which is null. It seems like I need to declare the array, but don't I need to tell it an exact size to do that? Example: lines = new string[10] I thought I could use the lines.Length to tell it how big to make the array but that didn't work. What is weird to me is I can use the following code without problem: //returns the accurate number of urls that were in the CSV we read in earlier txtbx1.text = lines.Length; //or //this returns the last entry in the csv, as well as the last entry in the array TextBox2.Text = lines[lines.Length - 1]; I am confused why the array clearly has items in it, they can be called to fill a text box, but when I try to call them in my for loop it says its a null reference? UPDATE: By placing my cursor on both calls to lines and pressing f12 I find they both go to the same instance. The thought next is that I am not calling ReadLinksIntoMemory in time, below is my code: private void button1_Click(object sender, EventArgs e) { button1.Enabled = false; ReadLinksIntoMemory(); GoToEditLinks(); button1.Enabled = true; } Unless I'm mistaken the code says that the ReadLinksIntoMemory method must complete before GoToEditLinks can be called? If ReadLinksIntoMemory didn't finish in time I shouldn't be able to fill my text boxes with the lines array length and/or last entry. UPDATE: Stepping into the method GoToEditLinks() I see that lines is null before it calls: myIE.GoTo(lines[i]); but when it hits the goto command the value changes from null to the url it is suppose to go to, but at that same time it gives me the null object error? UPDATE: I added a IsNullOrEmpty check method and lines array passes it without any issue. I'm beginning to think it is an issue with WatIn and the myIE.GoTo command. I think this is the stack trace/call stack? Program.exe!Program.Form1.GoToEditLinks() Line 284 C# Program.exe!Program.Form1.button1_Click(object sender, System.EventArgs e) Line 191 + 0x8 bytes C# [External Code] Program.exe!Program.Program.Main() Line 18 + 0x1d bytes C# [External Code]

    Read the article

  • CodedUI null reference exception even when object exists

    - by Roee
    Hi, I have created a coded ui test that checks something in my software. It worked fine, but now I keep getting null reference exception when I try to interact with the UITestControl. The starnge thing is, that the UITestControl's 'Exist' property returns true, which means that the control had been found. I've searched and found this topic: http://social.msdn.microsoft.com/Forums/en/vsautotest/thread/c2e6e5c3-2503-4506-9963-733fd84fbd25, But I have checked in my project, and the 'Copy Local' propert of these assemblies is set to false. I think that this execption first occurred after I have added an app.config file to my project. Maybe this might be the problem? If so, how can I fix this without deleting my app.config file? Thanks!

    Read the article

  • How to invoke a delegate with a null parameter?

    - by Rodney Burton
    I get a null exception if I try to pass a null parameter to a delegate during an invoke. Here's what the code looks like: public void RequestPhoto() { WCF.Service.BeginGetUserPhoto(Contact.UserID, new AsyncCallback(RequestPhotoCB), null); } public void RequestPhotoCB(IAsyncResult result) { var photo = WCF.Service.EndGetUserPhoto(result); UpdatePhoto(photo); } public delegate void UpdatePhotoDelegate(Binary photo); public void UpdatePhoto(Binary photo) { if (InvokeRequired) { var d = new UpdatePhotoDelegate(UpdatePhoto); Invoke(d, new object[] { photo }); } else { var ms = new MemoryStream(photo.ToArray()); var bmp = new Bitmap(ms); pbPhoto.BackgroundImage = bmp; } } The problem is with the line: Invoke(d, new object[] { photo }); If the variable "photo" is null. What is the correct way to pass a null parameter during an invoke? Thanks!

    Read the article

  • Disposing the members that implement IDisposable.

    - by Amby
    In my Dispose methods (like the one below), everytime i want to call someObj.Dispose() i also have a check for someObj!=null. Is that because of bad design on my part? Is their a cleaner way to ascertain that Dispose of all the members (implementing IDisposable) being used in an object is called without having a risk of NullReference exception ? protected void Dispose(bool disposing) { if (disposing) { if (_splitTradePopupManager != null) { _splitTradePopupManager.Dispose(); } } } Thanks for your interest.

    Read the article

  • Iterating through Event Log Entry Collection, IndexOutOutOfBoundsException

    - by fjdumont
    Hello, in a service application I am iterating through the Windows application event log to parse Events in order react depanding on the entry message. In the case that the event log is full (Windows usually makes sure there is enough space by deleting old entries - this is configurable in the eventvwr.exe settings), the service always runs into an IndexOutOfBoundsException while iterating through the EventLog.Entries collection. No matter how I iterate (for-loop, using the collections enumerator, copying the collection into an array, ...), I can't seem to get rid of this ´bug´. Currently, I ensure that the log is not full in order to keep the service running by regularly deleting the last few item by parsing the event log file and deleting the last few nodes (Don't beat me up, I couldn't find a better alternative...). How can I iterate through the collection without trying to access already deleted entries? Is there probably a more elegant method? I am only trying to acces the logs written during the last x seconds (even LINQ failed to select those when the log is full - same exception), could this help? Thanks for any advice and hints Frank Edit: I forgot to mention that my assumption is the loops are accessing entries which are being deleted during iteration by Windows. Basically that is why I tried to clone the collection. Is there perhaps a way to lock the collection for a small amount of time for just my application?

    Read the article

  • Async task ASP.net HttpContext.Current.Items is empty - How do handle this?

    - by GuruC
    We are running a very large web application in asp.net MVC .NET 4.0. Recently we had an audit done and the performance team says that there were a lot of null reference exceptions. So I started investigating it from the dumps and event viewer. My understanding was as follows: We are using Asyn Tasks in our controllers. We rely on HttpContext.Current.Items hashtable to store a lot of Application level values. Task<Articles>.Factory.StartNew(() => { System.Web.HttpContext.Current = ControllerContext.HttpContext.ApplicationInstance.Context; var service = new ArticlesService(page); return service.GetArticles(); }).ContinueWith(t => SetResult(t, "articles")); So we are copying the context object onto the new thread that is spawned from Task factory. This context.Items is used again in the thread wherever necessary. Say for ex: public class SomeClass { internal static int StreamID { get { if (HttpContext.Current != null) { return (int)HttpContext.Current.Items["StreamID"]; } else { return DEFAULT_STREAM_ID; } } } This runs fine as long as number of parallel requests are optimal. My questions are as follows: 1. When the load is more and there are too many parallel requests, I notice that HttpContext.Current.Items is empty. I am not able to figure out a reason for this and this causes all the null reference exceptions. 2. How do we make sure it is not null ? Any workaround if present ? NOTE: I read through in StackOverflow and people have questions like HttpContext.Current is null - but in my case it is not null and its empty. I was reading one more article where the author says that sometimes request object is terminated and it may cause problems since dispose is already called on objects. I am doing a copy of Context object - its just a shallow copy and not a deep copy.

    Read the article

  • Query Parameter Value Is Null When Enum Item 0 is Cast with Int32

    - by Timothy
    When I use the first item in a zero-based Enum cast to Int32 as a query parameter, the parameter value is null. I've worked around it by simply setting the first item to a value of 1, but I was wondering though what's really going on here? This one has me scratching my head. Why is the parameter value regarded as null, instead of 0? Enum LogEventType : int { SignIn, SignInFailure, SignOut, ... } private static DataTable QueryEventLogSession(DateTime start, DateTime stop) { DataTable entries = new DataTable(); using (FbConnection conn = new FbConnection(DSN)) { using (FbDataAdapter adapter = new FbDataAdapter( "SELECT event_type, event_timestamp, event_details FROM event_log " + "WHERE event_timestamp BETWEEN @start AND @stop " + "AND event_type IN (@signIn, @signInFailure, @signOut) " + "ORDER BY event_timestamp ASC", conn)) { adapter.SelectCommand.Parameters.AddRange(new Object[] { new FbParameter("@start", start), new FbParameter("@stop", stop), new FbParameter("@signIn", (Int32)LogEventType.SignIn), new FbParameter("@signInFailure", (Int32)LogEventType.SignInFailure), new FbParameter("@signOut", (Int32)LogEventType.SignOut)}); Trace.WriteLine(adapter.SelectCommand.CommandText); foreach (FbParameter p in adapter.SelectCommand.Parameters) { Trace.WriteLine(p.Value.ToString()); } adapter.Fill(entries); } } return entries; }

    Read the article

  • Silverlight logging out causes "Object reference not set to an instance"

    - by Alex
    I am using the Silverlight 4 Business Application Template. I've created a DomainDataSource in XAML like so: <riaControls:DomainDataSource x:Name="LogData" QueryName="GetLogs" AutoLoad="True" LoadSize="20" > <riaControls:DomainDataSource.DomainContext> <local:AdminDomainContext /> </riaControls:DomainDataSource.DomainContext> <riaControls:DomainDataSource.QueryParameters> <riaControls:Parameter ParameterName="UserLoginID" Value="{Binding Path=User.UserLoginID, Source={StaticResource WebContext}}" /> </riaControls:DomainDataSource.QueryParameters> </riaControls:DomainDataSource> The problem I'm experiencing is that whenever I log out, I get: Load operation failed for query 'GetLogs'. Object reference not set to an instance of an object. I assume that because I've logged out, User.UserLoginID is now null and is causing the exception. So... anybody know a good way for me to solve this? I don't really want to set the QueryParameter programmatically.

    Read the article

  • Query Parameter Value Is Null When Enum Item 0 is Cast to Int32

    - by Timothy
    When I use the first item in a zero-based Enum cast to Int32 as a query parameter, the parameter value is null. I've worked around it by simply setting the first item to a value of 1, but I was wondering though what's really going on here? This one has me scratching my head. Why does the parameter regarded the value as null, instead of 0? Enum LogEventType : int { SignIn, SignInFailure, SignOut, ... } private static DataTable QueryEventLogSession(DateTime start, DateTime stop) { DataTable entries = new DataTable(); using (FbConnection conn = new FbConnection(DSN)) { using (FbDataAdapter adapter = new FbDataAdapter( "SELECT event_type, event_timestamp, event_details FROM event_log " + "WHERE event_timestamp BETWEEN @start AND @stop " + "AND event_type IN (@signIn, @signInFailure, @signOut) " + "ORDER BY event_timestamp ASC", conn)) { adapter.SelectCommand.Parameters.AddRange(new Object[] { new FbParameter("@start", start), new FbParameter("@stop", stop), new FbParameter("@signIn", (Int32)LogEventType.SignIn), new FbParameter("@signInFailure", (Int32)LogEventType.SignInFailure), new FbParameter("@signOut", (Int32)LogEventType.SignOut)}); Trace.WriteLine(adapter.SelectCommand.CommandText); foreach (FbParameter p in adapter.SelectCommand.Parameters) { Trace.WriteLine(p.Value.ToString()); } adapter.Fill(entries); } } return entries; }

    Read the article

  • A Null Reference Exception

    - by Alex
    "Object reference not set to an instance of an object." using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.Graphics; namespace XNAdev { class Sprite { //The size of the Sprite public Rectangle Size; //Used to size the Sprite up or down from the original image public float Scale = 1.0f; //The current position of the Sprite public Vector2 Position = new Vector2(115, 0); //The texture object used when drawing the sprite private Texture2D mSpriteTexture; //Load the texture for the sprite using the Content Pipeline public void LoadContent(ContentManager theContentManager, string theAssetName) { mSpriteTexture = theContentManager.Load<Texture2D>(theAssetName); Size = new Rectangle(0, 0, (int)(mSpriteTexture.Width * Scale), (int)(mSpriteTexture.Height * Scale)); } //Draw the sprite to the screen public void Draw(SpriteBatch theSpriteBatch) { theSpriteBatch.Draw(mSpriteTexture, Position, new Rectangle(0, 0, mSpriteTexture.Width, mSpriteTexture.Height), Color.White, 0.0f, Vector2.Zero, Scale, SpriteEffects.None, 0); } } } I am very new at this C# so any help would be great. I have no idea what my error is.

    Read the article

  • Null reference but it's not?

    - by Clint Davis
    This is related to my previous question but it is a different problem. I have two classes: Server and Database. Public Class Server Private _name As String Public Property Name() As String Get Return _name End Get Set(ByVal value As String) _name = value End Set End Property Private _databases As List(Of Database) Public Property Databases() As List(Of Database) Get Return _databases End Get Set(ByVal value As List(Of Database)) _databases = value End Set End Property Public Sub LoadTables() Dim db As New Database(Me) db.Name = "test" Databases.Add(db) End Sub End Class Public Class Database Private _server As Server Private _name As String Public Property Name() As String Get Return _name End Get Set(ByVal value As String) _name = value End Set End Property Public Property Server() As Server Get Return _server End Get Set(ByVal value As Server) _server = value End Set End Property Public Sub New(ByVal ser As Server) Server = ser End Sub End Class Fairly simple. I use like this: Dim s As New Server s.Name = "Test" s.LoadTables() The problem is in the LoadTables in the Server class. When it hits Databases.Add(db) it gives me a NullReference error (Object reference not set). I don't understand how it is getting that, all the objects are set. Any ideas? Thanks.

    Read the article

  • Object reference not set to an instance of an object

    - by Ste
    I have this function that create runtime textbox: int i = 0; private TextBox[] addressBox = new TextBox[100]; private void appendNewTab() { addressBox[i] = new TextBox(); addressBox[i].KeyPress += new KeyPressEventHandler(this.addressBox_KeyPress); i++; } void addressBox_KeyPress(object sender, KeyPressEventArgs e) { if (e.KeyChar == (char)13) { MessageBox.Show(addressBox[i].Text); } } but i have Object reference not set to an instance of an object here MessageBox.Show(addressBox[i].Text); any suggestion?

    Read the article

  • Code producing System.NullReferenceException error for Membership.GetUser(). This is VB.Net (ASP.Net 4)

    - by Derrek
    I have a Default.aspx page that is not static. I have added functionality with datalist and sqldatasources. When a user logins he/she will see items like saved workouts, saved equipment, total replys, etc... This is based on getting the currently logged in user UserID. Quite simply this works great when the user is logged in. However, I do not want to force a user to login to view the Default page because it does have functionality on it that does not require login. When a user is not logged in of course I receive the [System.NullReferenceException] error. I understand the error well but I do not know how to code to fix it. That is where I need help. I will admit I am more designer than developer. However, I do know the exception error I am receivving is caused by me not setting a value in my code when a user is not logged in. I do not know how to do that and have for a week made unsuccessful attempts at writing the code. Both sets of code below compile for VB.Net/ASP.Net 4/Visual Studio 2010 without errors. However, I still get the System.NullReferenceException error if not logged in. I know it can be done but I do not know the right syntax. If you can help please insert you code in mine or write it out. JUST TELLING ME WHERE TO GO TO FIND AN ANSWER WON'T HELP. I HAVE DONE THAT FOR 7 STRAIGHT DAYS. I APPRECIATE OUR HELP. Partial Class _Default Inherits System.Web.UI.Page Protected Sub SqlDataSource4_Selecting(ByVal sender As Object, ByVal e As SqlDataSourceCommandEventArgs) Handles SqlDataSource4.Selecting Dim MemUser As MembershipUser MemUser = Membership.GetUser() If Not MemUser Is DBNull.Value Then UserID.Text = MemUser.ProviderUserKey.ToString() e.Command.Parameters("@UserId").Value = MemUser.ProviderUserKey.ToString() End If End Sub -------------------------------------ORIGINAL CODE------------------------------- Partial Class _Default Inherits System.Web.UI.Page Protected Sub SqlDataSource4_Selecting(ByVal sender As Object, ByVal e As SqlDataSourceCommandEventArgs) Handles SqlDataSource4.Selecting Dim MemUser As MembershipUser MemUser = Membership.GetUser() UserID.Text = MemUser.ProviderUserKey.ToString() e.Command.Parameters("@UserId").Value = MemUser.ProviderUserKey.ToString() End Sub

    Read the article

  • Why does Sitecore throw a NullReferenceException exception when I redirect to one of its pages?

    - by Abs
    I'm running Sitecore 6.1 on Windows 2008, IIS7, and I'm trying to use the URL Rewrite Module to do a redirect. When I enable the rule and hit the URL that triggers it, I get a YSOD. The same rule works perfectly on a non-sitecore site on the same machine. According to the Failed Request Trace, the rewrite module does its thing just fine, but then Sitecore throws an exception, even if the redirect points to another server. This is probably a result of something I have misconfigured, but I just can't understand why it doesn't work. The details from the YSOD are below. [NullReferenceException: Object reference not set to an instance of an object.] Sitecore.Nexus.Web.HttpModule.(Object sender, EventArgs e) +273 System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +68 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75

    Read the article

  • MySQL Throws NullReferenceException in Finalize... How are you coping with this?

    - by Cyril Gupta
    I am using MySQL with the .Net connector on 64 bit Windows. For some reason Mysql is throwing a NullReferenceException in Finalize. This is the problem here and it seems that its due to a bug described here. This bug was reported in 6.22, but I am getting the issue with 6.23 too so apparently it is not fixed. I am using MySQL both with the helper classes, and by instantiating the connection and the Mysqlcommand object. Does anybody have any idea what part of my code do I need to change to fix this issue? Cause even though this is a bug in Mysql this is not universal because I am not getting the problem in my other projects. MySQL bug report has no details on how to reproduce it either. Any suggestions?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 1 2 3 4 5 6 7 8 9 10 11  | Next Page >