What you want to use is this property:

    dt.Columns[0].DataType

The `DataType` property will set to one of the following:

    Boolean
    Byte
    Char
    DateTime
    Decimal
    Double
    Int16
    Int32
    Int64
    SByte
    Single
    String
    TimeSpan
    UInt16
    UInt32
    UInt64

[DataColumn.DataType Property MSDN Reference][1]


  [1]: http://msdn.microsoft.com/en-us/library/system.data.datacolumn.datatype.aspx

You could always use `typeof` in the if statement. It is better than working with string values like the answer of Natarajan.

    if (dt.Columns[0].DataType == typeof(DateTime))
    {
    }


    dt.Columns[0].DataType.Name.ToString()


You can get column type of DataTable with **DataType** attribute of datatable column like below:

```
var type = dt.Columns[0].DataType
```

`dt`: DataTable object.

`0`: DataTable column index.

```
if (dr[dc.ColumnName].GetType().ToString() == &quot;System.DateTime&quot;)
```

I was installing rails(v3) on my Ubuntu Linux Box &amp; the install failed complaining of missing javascript runtime. I did some lookup &amp; it turns out that rails require a javascript runtime to be installed on the platform its running. 

While, Windows has come bundled with jscript by default. My Ubuntu box didn&#39;t have a js runtime &amp; I fixed the issue by installing node.js(V8). 

AFAIK, a js runtime is required to execute javascript code &amp; rails is just a web framework in which javascript are embedded. Javascript files run only on client machines. 

So,
**Why does rails require JavaScript Runtime?**

Why does rails require JavaScript Runtime?

in my app I have users from different countries and want to perform finds on them

I tried to do it like this in the index action

     @fromcanada = User.find(:all, :country =&gt; &#39;canada&#39;)

but I got the error

     Unknown key: country

However, so that leads me to ask, what can become a key? In my database schema file, I have a &quot;country&quot; column on the users table. 

    t.string   &quot;country&quot;

Furthermore, when I did a find all

    @users = User.all

I was able to do this 


    &lt;%= user.country %&gt;&lt;/p&gt;

Can you explain why my find all with conditions didn&#39;t work?  and show me how I should have done it? 

Rails: Find all with conditions

    DataTable dt = new DataTable();  
    dt.Columns.Add(new DataColumn(gridColumn1, typeof(bool)));

I was expecting the result of the below line to include info about the DataColumns Type (bool):  

    ?dt.Columns[0].GetType()


Get a DataTable Columns DataType

<pre><code class="hljs language-csharp">DataTable dt = new DataTable(); 
dt.Columns.Add(new DataColumn(gridColumn1, typeof(bool)));
</code></pre>
I was expecting the result of the below line to include info about the DataColumns Type (bool):
<pre><code class="hljs language-css">?dt.Columns[0].GetType()
</code></pre>

I am trying to generate emails with HTML content.  this content has already gone through sanitation so I am not worried in that regard, however when I call:

    Razor.Parse(template, model);

on the following Razor template:

    &lt;!DOCTYPE HTML PUBLIC &quot;-//W3C//DTD HTML 4.0 Transitional//EN&quot;&gt;
    &lt;html&gt;
    	&lt;body&gt;
            @(new System.Web.HtmlString(Model.EmailContent))
    	&lt;/body&gt;
    &lt;/html&gt;

the email that is outputted is HTMl encoded, but I need it decoded.  How can I accomplish this?

How do I output raw html when using RazorEngine (NOT from MVC)

I have an EXE file reference in my C# project.  How do I invoke that EXE file from my code?





How can I run an EXE file from my C# code?

I&#39;m using the WCF4.0 template -[REST][1]. I&#39;m trying to make a method that uploads a file using a stream.

The problem always occur at

    Stream serverStream = request.GetRequestStream();

Class for streaming:

    namespace LogicClass
    {
        public class StreamClass : IStreamClass
        {
            public bool UploadFile(string filename, Stream fileStream)
            {
                try
                {
                    FileStream fileToupload = new FileStream(filename, FileMode.Create);
                    byte[] bytearray = new byte[10000];
                    int bytesRead, totalBytesRead = 0;
                    do
                    {
                        bytesRead = fileStream.Read(bytearray, 0, bytearray.Length);
                        totalBytesRead += bytesRead;
                    } while (bytesRead &gt; 0);

                    fileToupload.Write(bytearray, 0, bytearray.Length);
                    fileToupload.Close();
                    fileToupload.Dispose();
                }
                catch (Exception ex) { throw new Exception(ex.Message); }
                return true;
            }
        }
    }

REST project:

    [WebInvoke(UriTemplate = &quot;AddStream/{filename}&quot;, Method = &quot;POST&quot;, BodyStyle = WebMessageBodyStyle.Bare)]
    public bool AddStream(string filename, System.IO.Stream fileStream)
    {
        LogicClass.FileComponent rest = new LogicClass.FileComponent();
        return rest.AddStream(filename, fileStream);
    }

Windows Form project: for testing

    private void button24_Click(object sender, EventArgs e)
    {
        byte[] fileStream;
        using (FileStream fs = new FileStream(&quot;E:\\stream.txt&quot;, FileMode.Open, FileAccess.Read, FileShare.Read))
        {
            fileStream = new byte[fs.Length];
            fs.Read(fileStream, 0, (int)fs.Length);
            fs.Close();
            fs.Dispose();
        }

        string baseAddress = &quot;http://localhost:3446/File/AddStream/stream.txt&quot;;
        HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(baseAddress);
        request.Method = &quot;POST&quot;;
        request.ContentType = &quot;text/plain&quot;;
        Stream serverStream = request.GetRequestStream();
        serverStream.Write(fileStream, 0, fileStream.Length);
        serverStream.Close();
        using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
        {
            int statusCode = (int)response.StatusCode;
            StreamReader reader = new StreamReader(response.GetResponseStream());
        }
    }

I&#39;ve turned off the firewall and my Internet connection, but the error still exists. Is there a better way of testing the uploading method?

Stack trace:

&gt;at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)
       at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket&amp; socket, IPAddress&amp; address, ConnectSocketState state, IAsyncResult asyncResult, Int32 timeout, Exception&amp; exception)

  [1]: http://en.wikipedia.org/wiki/Representational_State_Transfer


No connection could be made because the target machine actively refused it 127.0.0.1:3446

What is the difference between `int`, `System.Int16`, `System.Int32` and `System.Int64` other than their sizes?

What is the difference between int, Int16, Int32 and Int64?

Is it forbidden in C# to implement a default constructor for a generic class?

If not, why the code below does not compile? (When I remove `&lt;T&gt;` it compiles though)

What is the correct way of defining a default constructor for a generic class then?


    public class Cell&lt;T&gt; 
    {
        public Cell&lt;T&gt;()
        {
        }
    }

**Compile Time Error**: Error	1	Invalid token &#39;(&#39; in class, struct, or interface member declaration	


What is the syntax for a default constructor for a generic class?

Is there a way to debug into a decompiled dll using Resharper and if so how do you do this?

For example I am trying to debug into `System.Web.Http.ApiController` where I have decompiled and can see the source. 

I have set a breakpoint but when I run the application it does not break into decompiled breakpoint when debugging.

Resharper debugging a third party decompiled dll

I know that [I can set up Visual Studio to debug through the .NET framework source code][1].

But is there a way that I can browse the code while NOT debugging - i.e., being able to press F12 or &quot;Go to definition&quot;?

I thought that if that feature isn&#39;t built into Visual Studio then there may be a plug-in that might add it?

  [1]: https://web.archive.org/web/20150822081658/http://blogs.msdn.com:80/b/sburke/archive/2008/01/16/configuring-visual-studio-to-debug-net-framework-source-code.aspx

Browsing the .NET Framework source code from Visual Studio

I have DataTable with two columns *Author* and *Bookname*.

I want to check if the given string value *Author* already exists in the DataTable. Is there some built in method to check it, like for Arrays  `array.contains`?  

Check if value exists in dataTable?

I have JSON in the following format:

    [
        {&quot;id&quot;:&quot;10&quot;,&quot;name&quot;:&quot;User&quot;,&quot;add&quot;:false,&quot;edit&quot;:true,&quot;authorize&quot;:true,&quot;view&quot;:true},
        {&quot;id&quot;:&quot;11&quot;,&quot;name&quot;:&quot;Group&quot;,&quot;add&quot;:true,&quot;edit&quot;:false,&quot;authorize&quot;:false,&quot;view&quot;:true},
        {&quot;id&quot;:&quot;12&quot;,&quot;name&quot;:&quot;Permission&quot;,&quot;add&quot;:true,&quot;edit&quot;:true,&quot;authorize&quot;:true,&quot;view&quot;:true}
    ]

How can I convert that into a C# `DataTable` object as follows?

    ---------------------------------------------------------------------
    ID    |  Name     |  Add    |   Edit  | View   | Authorize
    ---------------------------------------------------------------------
    10    | User      | true    |  true   | true   |  true
    11    | Group     | true    |  true   | true   |  true
    12    | Permission| true    |  true   | true   |  true

Convert JSON to DataTable

I&#39;m looking for a simple way to make a clone of a DataRow.  Kind of like taking a snapshot of that Row and saving it.  The values of original Row are then free to change but we still have another saved copy which doesn&#39;t change.  Is this the correct way to do it?

    DataRow Source, Destination;
    // Assume we create some columns and fill them with values
    Destination.ItemArray = Source.ItemArray;

Will this just set Snapshot&#39;s ItemArray reference to point to the one in Source or does it actually make a separate copy?  Should I do this instead?

    Destination.ItemArray = Source.ItemArray.Clone();

EDIT: I don&#39;t think the second code snippet actually compiles.

Simple way to copy or clone a DataRow?

I use a DataTable with Information about Users and I want search a user or a list of users in this DataTable. I try it butit don&#39;t work :( 

Here is my c# code:

     public DataTable GetEntriesBySearch(string username,string location,DataTable table)
            {
                list = null;
                list = table;
    
                string expression;
                string sortOrder;
    
                expression = &quot;Nachname = &#39;test&#39;&quot;;
                sortOrder = &quot;nachname DESC&quot;;
    
                DataRow[] rows =  list.Select(expression, sortOrder);
    
                list = null; // for testing
                list = new DataTable(); // for testing
     
                foreach (DataRow row in rows)
                {
                    list.ImportRow(row);
                }
    
                return list; 
            }

How I can filter a Datatable?

Is it possible to hide the Show Entries dropdown but keep the Search box in DataTable? I want to always display 10 rows with pagination at the bottom along with search box but do not want to display the Show entries dropdown.


Content Type	Original Author	Original Content on Stackoverflow
Question	Jeremy Thompson	View Question on Stackoverflow
Solution 1 - C#	user596075	View Answer on Stackoverflow
Solution 2 - C#	VDWWD	View Answer on Stackoverflow
Solution 3 - C#	Natarajan Sambantham	View Answer on Stackoverflow
Solution 4 - C#	Arpit Trivedi	View Answer on Stackoverflow
Solution 5 - C#	Vinod Parmar	View Answer on Stackoverflow

Get a DataTable Columns DataType

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

Solution 3 - C#

Solution 4 - C#

Solution 5 - C#

Rails: Find all with conditions

Why does rails require JavaScript Runtime?

Attributions