Search Results

Search found 43645 results on 1746 pages for 'student question'.

Page 57/1746 | < Previous Page | 53 54 55 56 57 58 59 60 61 62 63 64  | Next Page >

  • Databinding question: DataGridView <=> XDocument (using LINQ-to-XML)

    - by Pretzel
    Learning LINQ has been a lot of fun so far, but despite reading a couple books and a bunch of online resources on the topic, I still feel like a total n00b. Recently, I just learned that if my query returns an Anonymous type, the DataGridView I'm populating will be ReadOnly (because, apparently Anonymous types are ReadOnly.) Right now, I'm trying to figure out the easiest way to: Get a subset of data from an XML file into a DataGridView, Allow the user to edit said data, Stick the changed data back into the XML file. So far I have Steps 1 and 2 figured out: public class Container { public string Id { get; set; } public string Barcode { get; set; } public float Quantity { get; set; } } // For use with the Distinct() operator public class ContainerComparer : IEqualityComparer<Container> { public bool Equals(Container x, Container y) { return x.Id == y.Id; } public int GetHashCode(Container obj) { return obj.Id.GetHashCode(); } } var barcodes = (from src in xmldoc.Descendants("Container") where src.Descendants().Count() > 0 select new Container { Id = (string)src.Element("Id"), Barcode = (string)src.Element("Barcode"), Quantity = float.Parse((string)src.Element("Quantity").Attribute("value")) }).Distinct(new ContainerComparer()); dataGridView1.DataSource = barcodes.ToList(); This works great at getting the data I want from the XML into the DataGridView so that the user has a way to manipulate the values. Upon doing a Step-thru trace of my code, I'm finding that the changes to the values made in DataGridView are not bound to the XDocument object and as such, do not propagate back. How do we take care of Step 3? (getting the data back to the XML) Is it possible to Bind the XML directly to the DataGridView? Or do I have to write another LINQ statement to get the data from the DGV back to the XDocument? Suggstions?

    Read the article

  • Objective-C assigning variables question for iphone.

    - by coder net
    The following piece of code can be written in two ways. I would like to know what are the pros and cons of each. If possible I would like to stick with the one liner. 1) UIColor *background = [[UIColor alloc] initWithPatternImage:[UIImage imageNamed:@"Background.png"]]; self.view.backgroundColor = background; [background release]; 2) self.view.backgroundColor = [[UIColor alloc] initWithPatternImage:[UIImage imageNamed:@"Background.png"]]; Any issues with releasing memory etc. with #2? I'm new to Objective-C and would like to follow the best approach.

    Read the article

  • WPF Binding Question - Change Label Text based on Modifier Key Control

    - by Chuck Savage
    I have a context menu, that I'd like to change the Header based on whether the Control Key is pressed or not. Right now I have, <MenuItem Header="Send To"> <MenuItem ... /> <MenuItem ... /> </MenuItem> I'd like based on the Control Key being down to be, <MenuItem Header="Move To"> <MenuItem ... /> <MenuItem ... /> </MenuItem> All I really need to do is change the Header text, because inside the code I know how to check for the Modifier key being Control.

    Read the article

  • HTML/CSS layout question

    - by TheDelChop
    Guys, I just need a little help with some CSS layout if you don't mind. I've got three things I'm trying to play around with and I need some help making this work the way I was hoping. I've got the element of a page, which I'd like to be 100% of the browser window, obviously. Then I've got two elements which I'd like to stack on top of each other, but the trick is this, I'd like the bottom div, (a menu which should really be a fixed height) to determine the height of the top div. Is there a way to lay this out in CSS?

    Read the article

  • Regex question in C#

    - by Gold
    hi how to remove only one char (") if there two("") from the string in C# (Regex ) ex.: 123"43""343"54"" ==> 123"43"343"54" "abc""def"gh""i ==> "abc"def"gh"i thank's in advance

    Read the article

  • SQL DISTINCT Value Question

    - by CPOW
    How can I filter my results in a Query? example I have 5 Records John,Smith,apple Jane,Doe,apple Fred,James,apple Bill,evans,orange Willma,Jones,grape Now I want a query that would bring me back 3 records with the DISTINCT FRUIT, BUT... and here is the tricky part, I still want the columns for First Name , Last Name. PS I do not care which of the 3 it returns mind you, but I need it to only return 3 (or what ever how many DISTINCT fruit there are. ex return would be John,Smith,apple Bill,evans,orange Willma,Jones,grape Thanks in advance I've been banging my head on this all day.

    Read the article

  • Question about functional OOP style in JavaScript

    - by valums
    I prefer to use functional OOP style for my code (similar to the module pattern) because it helps me to avoid the "new" keyword and all problems with the scope of "this" keyword in callbacks. But I've run into a few minor issues with it. I would like to use the following code to create a class. namespace.myClass = function(){ var self = {}, somePrivateVar1; // initialization code that would call // private or public methods privateMethod(); self.publicMethod(); // sorry, error here function privateMethod(){} self.publicMethod = function(){}; return self; } The problem is that I can't call public methods from my initialization code, as these functions are not defined yet. The obvious solution would be to create an init method, and call it before "return self" line. But maybe you know a more elegant solution? Also, how do you usually handle inheritance with this pattern? I use the following code, butI would like to hear your ideas and suggestions. namespace.myClass2 = function(){ var self = namespace.parentClass(), somePrivateVar1; var superMethod = self.someMethod; self.someMethod = function(){ // example shows how to overwrite parent methods superMethod(); }; return self; } Edit. For those who asked what are the reasons for choosing this style of OOP, you can look into following questions: http://stackoverflow.com/questions/1557386/prototypal-vs-functional-oop-in-javascript http://stackoverflow.com/questions/383402/is-javascript-s-new-keyword-considered-harmful

    Read the article

  • A simple question about string.replace in C#

    - by Taz
    For example I have code below string txt="I have strings like West, and West; and west, and Western." I would like to replace the word west or West with some other word. But I would like not to replace West in Western. Can I use regular expression in string.replace? I used inputText.Replace("(\\sWest.\\s)",temp); It dos not work.

    Read the article

  • General N-Tier Architecture Question

    - by whatispunk
    In an N-Tier app you're supposed to have a business logic layer and a data access layer. Is it bad to simply have two assemblies: BusinessLogicLayer.dll and DataAccessLayer.dll to handle all this logic? How do you actually represent these layers. It seems silly, the way I've seen it, to have a BusinessLogic class library containing classes like: CustomerBusinessLogic.cs, OrderBusinessLogic.cs, etc. each calling their appropriately named cousin in the DataAccessLayer class library, i.e. CustomerDataAccess.cs, OrderDataAccess.cs. I want to create a web app using MVP and it doesn't seem so cut and dry as this. There are lots of opinions about where the business logic is supposed to be put in MVP and I'm not sure I've found a really great answer yet. I want this project to be easily testable, and I am trying to adhere to TDD methodologies as best I can. I intend to use MSTest and Rhino Mocks for testing. I was thinking of something like the following for my architecture: I'd use LINQ-To-SQL to talk to the database. WCF services to define data contract interfaces for the business logic layer. Then use MVP with ASP.NET Forms for the UI/BLL. Now, this isn't the start of this project, most of the LINQ stuff is already done, so its stuck. The WCF service would replace the existing DataAccessLayer assembly and the UI/BLL would replace the BusinessLogicLayer assembly etc. This sort of makes sense in my head, but its getting really late. Anyone that's traveled down this path have any guidance? Good links? Warnings? Thanks!

    Read the article

  • Sharing elements between Android apps, a question of best practices

    - by Emanuil
    Here's a quote from Android's Dev Guide: A central feature of Android is that one application can make use of elements of other applications (provided those applications permit it). For example, if your application needs to display a scrolling list of images and another application has developed a suitable scroller and made it available to others, you can call upon that scroller to do the work, rather than develop your own. Isn't it a bad practice to make an app dependent on other apps?

    Read the article

  • Quick Java question about variables

    - by Spencer
    I'm declaring a variable: private static final String filename = "filename.txt"; First, does the order of private static final matter? If not, is there a standard excepted sequence or convention? Second, the filename in my application is fixed. Is this the best was to store it's value? Thanks, Spencer

    Read the article

  • PHP strlen question

    - by MrEnder
    Ok I am checking that a string is at least 4 characters long and 25 or less characters short I tried to use strlen like this $userNameSignupLength = strlen($userNameSignup); else if($userNameSignupLength<4 && $userNameSignupLength>25) { $userNameSignupError = "Must be between 4 to 25 characters long"; } but it doesn't work... what did I do wrong?

    Read the article

  • Easy Javascript Regex Question

    - by Matrym
    Why doesn't this assign prepClass to the string selectorClass with underscores instead of non alpha chars? What do I need to change it to? var regex = new RegExp("/W/", "g"); var prepClass = selectorClass.replace(regex, "_");

    Read the article

  • sharp architecture question, nhibernate validation

    - by csetzkorn
    I have marked certain properties in my domain object for the nhibernate validation 'framework'. If I do this in my controller explicitly: ICollection<IValidationResult> test = bla.ValidationResults(); I get the validation errors which I could add to my asp.net mvc modelstate ideally, i would like an exception being thrown during: bla = blaRepository.SaveOrUpdate(bla); if i try to save or update the domain object. why is this not happening? my domain object bla derives from Entity. do I have to register something somehow? Thanks. christian

    Read the article

  • R Question: calculating deltas in a timeseries

    - by Jörg Beyer
    I have a timeseries of samples in R: > str(d) 'data.frame': 5 obs. of 3 variables: $ date: POSIXct, format: "2010-03-04 20:47:00" "2010-03-04 21:47:00" ... $ x : num 0 10 11 15.2 20 $ y : num 0 5 7.5 8.4 12.5 > d date x y 1 2010-03-04 20:47:00 0.0 0.0 2 2010-03-04 21:47:00 10.0 5.0 3 2010-03-04 22:47:00 11.0 7.5 4 2010-03-04 23:47:00 15.2 8.4 5 2010-03-05 00:47:00 20.0 12.5 In this example samples for x and y are taken every hour (but the time delta is not fix). The x and y values are always growing (like a milage counter in a car). I need the deltas, how much was the growth in between, something like this: 1 2010-03-04 20:47:00 0.0 0.0 2 2010-03-04 21:47:00 10.0 5.0 3 2010-03-04 22:47:00 1.0 2.5 4 2010-03-04 23:47:00 4.2 0.9 5 2010-03-05 00:47:00 4.8 4.1 And I also need the detlas per time (x and y delta, divided by the time - delta per hour) How would I do this in R?

    Read the article

  • Android NDK Question

    - by Kyle
    The NDK does not contain very many shared libraries for you to access. As a result, I must build many sources myself and link them into my shared library via static/shared libraries. I want to compile libpng as a Static Library. Trouble is, I have absolutely no idea how, nor does google instruct you how to do so in their NDK. I'm no expert on the NDK even after reading everything I can find, so I would really appreciate someone who actually knows how this is done. I do have the Android.mk file for libpng, as google's Android OS source contains it. Infact, I got the entire directory on the android OS source for libpng and it's dependent libraries. It was somewhat of a shortcut instead of making one myself. I don't know how to make a particular directory which contains this file, though. Thanks for reading!

    Read the article

  • Decoding a GIF question

    - by teehoo
    For a personal project I'm creating a static gif decoder. Everything works well so far, except I'm having trouble understanding one concept from the specification: This block is REQUIRED for an image. Exactly one Image Descriptor must be present per image in the Data Stream. An unlimited number of images may be present per Data Stream. (Spec) Unlimited images per data stream? There can be more than 1? I'm assuming they don't mean an animated GIF because in the same specification they state, that they don't recommend gif's be used for animation. I've read a lot of other sites documenting the gif format and they all state something similar. Heres another link: There might be an unlimited number of images present in a GIF. Any ideas?

    Read the article

  • PHP security question?

    - by pHp
    I just wanted to know what are some basic PHP security techniques I should use when creating a web page that accepts articles? I'm fairly new to PHP and was wondering what will hold the fort down until I'm a security expert?

    Read the article

  • Question about mixing MEF and Unity

    - by Dave
    I'm finally diving into Unity head first, and have run into my first real problem. I've been gradually changing some things in my app from being MEF-resolved to Unity-resolved. Everything went fine on the application side, but then I realized that my plugins were not being loaded. I started to look into this issue, and I believe it's a case where MEF and Unity don't mix. Plugins are loaded by MEF, but each plugin needs to get access to the shared libraries in my application, like app preferences, logging, etc. Initially, my plugin constructor had the ImportingConstructor attribute. I then replaced it with InjectionConstructor so that Unity could resolve its shared library dependencies. But because I did that, MEF no longer loaded it! Then I used both attributes, which compiled, but then I got a composition error (MEF). I figured that this was because the constructor takes a parameter that was once resolved by a MEF Import, so I removed all parameters. As expected, now MEF was able to load my plugin, but because the constructor needs to call into the interface that was once passed in, construction fails. So now I'm at a point where I can get MEF to start to load my plugin, but can't do anything with it because the plugin relies on shared libraries that are registered with Unity. For those of you that have successfully mixed MEF and Unity, how do you go about resolving the references to the shared libraries with Unity? It seems like a catch-22, where in order to have Unity work with the plugin, I'd have to create the plugin via Resolve, but then it's impossible to use MEF. UPDATE I can work around this problem by using an ImportingConstructor for the plugin that takes an IUnityContainer, and then call Resolve for each interface that I need, but although it works, it is incredibly lame to do it this way, as this would require all plugin authors to remember to save a reference to the passed in IUnityContainer...

    Read the article

  • Newbie database index question

    - by RenderIn
    I have a table with multiple indexes, several of which duplicate the same columns: Index 1 columns: X, B, C, D Index 2 columns: Y, B, C, D Index 3 columns: Z, B, C, D I'm not very knowledgeable on indexing in practice, so I'm wondering if somebody can explain why X, Y and Z were paired with these same columns. B is an effective date. C is a semi-unique key ID for this table for a specific effective date B. D is a sequence that identifies the priority of this record for the identifier C. Why not just create 6 indexes, one for each X, Y, Z, B, C, D? I want to add an index to another column T, but in some contexts I'll only be querying on T alone while in others I will also be specifying the B, C and D columns... so should I create just one index like above or should I create one for T and one for (T, B, C, D)? I've not had as much luck as expected when googling for comprehensive coverage of indexing. Any resources where I can get a through explanation and lots of examples of B-tree indexing?

    Read the article

  • Academic question: typename

    - by Arman
    Hi, recently I accounted with a "simple problem" of porting code from VC++ to gcc/intel. The code is compiles w/o error on VC++: #include <vector> using std::vector; template <class T> void test_vec( std::vector<T> &vec) { typedef std::vector<T> M; /*==> add here typename*/ M::iterator ib=vec.begin(),ie=vec.end(); }; int main() { vector<double> x(100, 10); test_vec<double>(x); return 0; } then with g++ we have some unclear errors: g++ t.cpp t.cpp: In function 'void test_vec(std::vector<T, std::allocator<_CharT> >&)': t.cpp:13: error: expected `;' before 'ie' t.cpp: In function 'void test_vec(std::vector<T, std::allocator<_CharT> >&) [with T = double]': t.cpp:18: instantiated from here t.cpp:12: error: dependent-name 'std::M::iterator' is parsed as a non-type, but instantiation yields a type t.cpp:12: note: say 'typename std::M::iterator' if a type is meant If we add typename before iterator the code will compile w/o pb. If it is possible to make a compiler which can understand the code written in the more "natural way", then for me is unclear why we should add typename? Which rules of "C++ standards"(if there are some) will be broken if we allow all compilers to use without "typename"? kind regards Arman.

    Read the article

< Previous Page | 53 54 55 56 57 58 59 60 61 62 63 64  | Next Page >