It seems to me that you have an untyped view. By default, Razor views in MVC3 RC are typed as `dynamic`. However, lambdas do not support dynamic members. You have to strongly type your model. At the top of your view file add

    @model SampleModel

A common error that is the cause of this is when you add 

    @Model SampleModel

at the top of the page instead of

    @model SampleModel



In this [link][1] explain about @model, see a excerpt:

&gt; `@model` (lowercase &quot;m&quot;) is a reserved keyword in Razor views to
&gt; declare the model type at the top of your view. You have put the
&gt; namespace too, e.g.: `@model MyNamespace.Models.MyModel`
&gt; 
&gt; Later in the file, you can reference the attribute you want with
&gt; `@Model.Attribute` (uppercase &quot;M&quot;).


  [1]: https://stackoverflow.com/a/7562489/1535626

Seems like your view is typed `dynamic`. Set the right type on the view and you&#39;ll see the error go away.

Before using (strongly type html helper into view) this line 

    @Html.TextBoxFor(p =&gt; p.Product.Name)

You should include your model into you page for making strongly type view.
 

    @model SampleModel

This error happened to me because I had @@model instead of @model... copy &amp; paste error in my case.  Changing to @model fixed it for me.

Can I specify that I want gdb to break at line x when `char* x` points to a string whose value equals `&quot;hello&quot;`? If yes, how?



How do I set a conditional breakpoint in gdb, when char* x points to a string whose value equals &quot;hello&quot;?

I want to fire an event when the user select a file. Doing so with `.change` event it works if the user changes the file every time.

But I want to fire the event if the user select the same file again.

 1. User select file `A.jpg` (event fires)
 2. User select file `B.jpg` (event fires)
 3. User select file `B.jpg` (event doesn&#39;t fire, I want it to fire)

How can I do it?

How to detect input type=file &quot;change&quot; for the same file?

I have a model similar to this:

    public class SampleModel
    {
         public Product Product { get; set; } 
    }

And in my controller I get an exception trying to print out

    @Html.TextBoxFor(p =&gt; p.Product.Name)

This is the error:

&lt;!-- language: lang-none --&gt;

    Exception: An expression tree may not contain a dynamic operation


If anyone can give me some clues on how to fix this I would really appreciate it!

Razor View Engine : An expression tree may not contain a dynamic operation

I have a model similar to this:
<pre><code class="hljs language-arduino">public class SampleModel
{
 public Product Product { get; set; } 
}
</code></pre>
And in my controller I get an exception trying to print out
<pre><code class="hljs language-ini">@Html.TextBoxFor(p => p.Product.Name)
</code></pre>
This is the error:

<pre><code class="hljs language-csharp">Exception: An expression tree may not contain a dynamic operation
</code></pre>
If anyone can give me some clues on how to fix this I would really appreciate it!

I am writing a Asp.net MVC 2 application that uses Forms Authentication and currently I am having a problem with our iPhone application in regards to the authentication/login over the web. We have developed a simple iPhone app that uses the the UIWebView control. At this stage, all the app does is navigate to our Asp.Net website. Simple, right? The problem is, that the user cannot get past the login page. The repro steps are:

 * Open iPhone app.
 * The app navigates to the home page.
 * the user is not authenticated, so they are redirected to the login screen/page
 * The user enters the correct user name and password. clicks submit.
 * on the server side, the user is authenticated and a cookie is generated and sent to the client using FormsAuthentication.GetAuthCookie.
 * The server sends are redirect to send the user to the correct home page.

But the user is then redirected &lt;b&gt;BACK&lt;/b&gt; to the login screen!

I&#39;ve done some extensive debugging on this and what I do know is: 

The cookie is being sent to the client, and the client is storing the cookie. Verified this in the iPhone debugger and also by using Javsascript to display cookie data on the page. The cookie is being sent back to the server. Verified this in the Visual Studio debugger. It is the correct cookie (it&#39;s the same one that was set). The property User.Identity.IsAuthenticated returns false for some reason, even though the auth cookie is contained in the Request object.  I have verified that the iPhone app is setup to accept cookies, and they are on the client.

Here is the funny thing: It works fine if you open the Safari browser on the iPhone and go to our site directly. 

It has the same behaviour on the iPad too in that it doesn&#39;t get past the login screen. This repros on the emulators, and on devices.

This same web site has been tested with IE 7-8, Safari (for Windows), Blackberry, IEMobile 6.5, Phone 7 and it works find. The only circumstance that it doesn&#39;t work on is the UIWebView in the iPhone app.


 

Asp.Net Forms Authentication when using iPhone UIWebView

I can use ContentPlaceHolder&#39;s with Webforms view engines to put stuff in different locations in the master page.

How do I do that with Razor?

        &lt;div id=&quot;content&quot;&gt;
            &lt;asp:ContentPlaceHolder ID=&quot;MainContent&quot; runat=&quot;server&quot;&gt;
            &lt;/asp:ContentPlaceHolder&gt;
        &lt;/div&gt; 
        &lt;div id=&quot;footer&quot;&gt;
            &lt;asp:ContentPlaceHolder ID=&quot;Footer&quot; runat=&quot;server&quot;&gt;
            &lt;/asp:ContentPlaceHolder&gt;
        &lt;/div&gt;


ContentPlaceHolder in Razor?

Im trying to get a list of line items to a webpage using JSON, which will then be manipulated and sent back to the server by ajax request using the same JSON structure that arrived (except having had a field values changed). 

Receiving data from the server is easy, manipulation even easier! but sending that JSON data back to the server for saving... suicide time! PLEASE can someone help!

**Javascript**

    var lineitems;

    // get data from server
    $.ajax({
        url: &#39;/Controller/GetData/&#39;,
        success: function(data){
            lineitems = data;
        }
    });
    
    // post data to server
    $.ajax({
        url: &#39;/Controller/SaveData/&#39;,
        data: { incoming: lineitems }
    });

**C# - Objects**

    public class LineItem{
        public string reference;
        public int quantity;
        public decimal amount;
    }

**C# - Controller**

    public JsonResult GetData()
    {
        IEnumerable&lt;LineItem&gt; lineItems = ... ; // a whole bunch of line items
        return Json(lineItems);
    }
    
    public JsonResult SaveData(IEnumerable&lt;LineItem&gt; incoming){
        foreach(LineItem item in incoming){
            // save some stuff
        }
        return Json(new { success = true, message = &quot;Some message&quot; });
    }

The data arrives at the server as serialized post data. The automated model binder tries to bind `IEnumerable&lt;LineItem&gt; incoming` and surprisingly gets the resulting `IEnumerable` has the correct number of `LineItems` - it just doesnt populate them with data.

**SOLUTION**

Using answers from a number of sources, primarily `djch` on another stackoverflow post and `BeRecursive` below, I solved my problem using two main methods.

*Server Side* 

The deserialiser below requires reference to `System.Runtime.Serialization` and `using System.Runtime.Serialization.Json`

	private T Deserialise&lt;T&gt;(string json)
	{
	    using (var ms = new MemoryStream(Encoding.Unicode.GetBytes(json)))
	    {
	        var serialiser = new DataContractJsonSerializer(typeof(T));
	        return (T)serialiser.ReadObject(ms);
	    }
	}
	
	public void Action(int id, string items){
	    IEnumerable&lt;LineItem&gt; lineitems = Deserialise&lt;IEnumerable&lt;LineItem&gt;&gt;(items);
	    // do whatever needs to be done - create, update, delete etc.
	}

*Client Side*

It uses json.org&#39;s stringify method, available in this dependecy https://github.com/douglascrockford/JSON-js/blob/master/json2.js (which is 2.5kb when minified)

    $.ajax({
        type: &#39;POST&#39;,
        url: &#39;/Controller/Action&#39;,
        data: { &#39;items&#39;: JSON.stringify(lineItems), &#39;id&#39;: documentId }
    });

Posting JSON Data to ASP.NET MVC

I am having difficulty with Html Helpers when used with Razor.  Said helpers worked fine in MVC 2 with the web form view engine.  But not in razor.  The error I get at runtime is:

    Compiler Error Message: CS1502: The best overloaded method match for &#39;System.Web.WebPages.WebPageExecutingBase.Write(System.Web.WebPages.HelperResult)&#39; has some invalid arguments
    
    Source Error:
    
    
    Line 1:  @using Wingspan.Web.Mvc;
    Line 2:  @Html.IncrementalMenu(MenuBlock.Site)

Expanding the Show Detailed Compiler Output reveals:

    d:\...\Views\Shared\MenuTop.cshtml(2,1): error CS1502: The best overloaded method match for &#39;System.Web.WebPages.WebPageExecutingBase.Write(System.Web.WebPages.HelperResult)&#39; has some invalid arguments
    d:\...\Views\Shared\MenuTop.cshtml(2,7): error CS1503: Argument 1: cannot convert from &#39;void&#39; to &#39;System.Web.WebPages.HelperResult&#39;

That indicates to me that razor doesn&#39;t like my helper, IncrementalMenu, returning void (which works fine in MVC 2 web form engine views).

I get no errors at Compile time, although the line of code (@Html.IncrementalMenu(...)) is red underlined with the following message:

    Cannot implicitly convert type &#39;void&#39; to &#39;object&#39;


IncrementalMenu is in the Wingspan.Web.Mvc namespace.  It&#39;s signature is as follows:

    public static void IncrementalMenu(this HtmlHelper html, MenuBlock menuBlock)
    {
        // Uses an HtmlTextWriter to render a menu from the sitemap
    }

I&#39;m blowed if I know what is wrong...

PS:

The MenuBlock parameter is just an enum that identifies how the menu should render.  Don&#39;t fixate on this as that is fine.

ASP.NET MVC: Custom Html Helpers in Razor

I have a textarea control that accepts input. I am trying to later render that text to a view by simply using:

&gt; @Model.CommentText

This is properly encoding any values.  However, I want to replace the line break characters with `&lt;br /&gt;` and I can&#39;t find a way to make sure that the new br tags don&#39;t get encoded. I have tried using HtmlString but haven&#39;t had any luck yet. 

Replace line break characters with &lt;br /&gt; in ASP.NET MVC Razor view

Does it make sense to you to use for every normal foreach a parallel.foreach loop ?

When should I start using parallel.foreach, only iterating 1,000,000 items?

Should I always use Parallel.Foreach because more threads MUST speed up everything?

I have created a cache using the MemoryCache class. I add some items to it but when I need to reload the cache I want to clear it first. What is the quickest way to do this? Should I loop through all the items and remove them one at a time or is there a better way?

How to clear MemoryCache?

I Installed DotNetOpenAuth SDK-3.4.5.10201.vsix and I can&#39;t get it working.
It works locally (when I run as localhost) but when i try to publish it ain&#39;t working. 

The IIS error message I get is 

&gt; Error Summary  
  HTTP Error 500.22 - Internal Server Error  
  An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode.

AND

&gt;     Module       ConfigurationValidationModule  
    Notification BeginRequest  
    Handler      StaticFile  
    Error Code   0x80070032  

then there are some suggestions on how to solve the problem:

Things you can try:

&gt; * Migrate the configuration to the
       `system.webServer/modules` section. You
       can do so manually or by using AppCmd
       from the command line - for example,
       `%SystemRoot%\system32\inetsrv\appcmd
       migrate config &quot;Default Web Site/&quot;`.
       Using `AppCmd` to migrate your
       application will enable it to work in
       Integrated mode, and continue to work
       in Classic mode and on previous
       versions of IIS.

&gt; * If you are certain that it is OK to
       ignore this error, it can be disabled
       by setting
       `system.webServer/validation@validateIntegratedModeConfiguration`
       to false.  

&gt; * Alternatively, switch the application
       to a Classic mode application pool -
       for example,
       `%SystemRoot%\system32\inetsrv\appcmd
       set app &quot;Default Web Site/&quot;
       /applicationPool:&quot;Classic .NET
       AppPool&quot;`. Only do this if you are
       unable to migrate your application.  
       (Set &quot;Default Web Site&quot; and &quot;Classic .NET AppPool&quot; to your application path and application pool name)


But the problem is that I don&#39;t have access to the ISS server as I am not the owner of it. Is there any way to solve this?


An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode

We could abort a `Thread` like this:

    Thread thread = new Thread(SomeMethod);
    .
    .
    .
    thread.Abort();

But can I abort a `Task` (in .Net 4.0) in the same way not by cancellation mechanism. **I want to kill the Task immediately.**

How to abort a Task like aborting a Thread (Thread.Abort method)?

Background: I&#39;m new to WinDbg and trying to get it running for the first time. I want to examine a memory dump I took from a running ASP.NET 4 site hosted in IIS 7 on Windows Server 2008 (x86) and downloaded to my local machine.

I installed the [debugging tools][1] and launched WinDbg for the first time, opening the crash dump. I went to **File | Symbol File Path** and set the path to `*srv*c:\symbols*http://msdl.microsoft.com/download/symbols*` and waited for all the symbols to load.

When trying to load SOS, I ran into problems. First, I tried the following command...

    .loadby sos mscorwks

...and received the response `Unable to find module &#39;mscorwks&#39;`.

After scouring the web, I tried to load mscorwks by executing the following command...

    sxe ld mscorwks.dll
    g

...and received the response &quot;No runnable debuggees error in &#39;g&#39;&quot;

I copied SOS.dll (from C:\Windows\Microsoft.NET\Framework\v4.0.30319) into the WinDbg directory, then tried...

    .load sos

...and received the error...

    The call to LoadLibrary(sos) failed, Win32 error 0n193
        &quot;%1 is not a valid Win32 application.&quot;
    Please check your debugger configuration and/or network access.

I&#39;m not quite sure how to proceed. I just want to load SOS and dig around this dump file. Any help would be greatly appreciated.

Fyi...I am trying to open the dump file on a 64-bit version of Windows 7 with the 64-bit version of Windbg.

  [1]: http://www.microsoft.com/whdc/devtools/debugging/default.mspx

Unable to load SOS in WinDbg

I was trying to use the following statement:

    @Html.Test&lt;ISQL&gt;().Nand()

However, Razor is choking at the &lt; before the ISQL.

Any official work around for it?

How to use generic syntax inside a Razor view file?

I&#39;ve got safe/sanitized HTML saved in a DB table.

How can I have this HTML content written out in a Razor view? 

It always escapes characters like `&lt;` and ampersands to `&amp;amp;`.

Content Type	Original Author	Original Content on Stackoverflow
Question	femseks	View Question on Stackoverflow
Solution 1 - asp.net Mvc	marcind	View Answer on Stackoverflow
Solution 2 - asp.net Mvc	felbus	View Answer on Stackoverflow
Solution 3 - asp.net Mvc	Charlestown	View Answer on Stackoverflow
Solution 4 - asp.net Mvc	Esteban Araya	View Answer on Stackoverflow
Solution 5 - asp.net Mvc	Kuber	View Answer on Stackoverflow
Solution 6 - asp.net Mvc	JosephDoggie	View Answer on Stackoverflow
Solution 7 - asp.net Mvc	Perry	View Answer on Stackoverflow

Razor View Engine : An expression tree may not contain a dynamic operation

asp.net Mvc Problem Overview

asp.net Mvc Solutions

Solution 1 - asp.net Mvc

Solution 2 - asp.net Mvc

Solution 3 - asp.net Mvc

Solution 4 - asp.net Mvc

Solution 5 - asp.net Mvc

Solution 6 - asp.net Mvc

Solution 7 - asp.net Mvc

How to detect input type=file "change" for the same file?

How do I set a conditional breakpoint in gdb, when char* x points to a string whose value equals "hello"?

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