Use a semicolon

    OpenFileDialog of = new OpenFileDialog();
    of.Filter = &quot;Excel Files|*.xls;*.xlsx;*.xlsm&quot;;

If you want to merge the filters (eg. CSV and Excel files), use this formula:

    OpenFileDialog of = new OpenFileDialog();
    of.Filter = &quot;CSV files (*.csv)|*.csv|Excel Files|*.xls;*.xlsx&quot;;


Or if you want to see XML or PDF files in one time use this:

    of.Filter = @&quot; XML or PDF |*.xml;*.pdf&quot;;

## General Questions ##
Hello! I&#39;m delving into the world of Chrome Extensions and am having some problems getting the overall workflow down. It seems that Google has recently switched to heavily advocating Event Pages instead of keeping everything in background.js and background.html. I take part of this to mean that we should pass off most of your extension logic to a content script.

In [Google&#39;s Event Page primer](https://developer.chrome.com/extensions/event_pages.html), they have the content script listed in the manifest.json file. But in their event page example extension, it is brought in via this code block in background.js: `chrome.tabs.executeScript(tab.id, {file: &quot;content.js&quot;}, function() { });`

What are the advantages of doing it one way over the other?

## My Code ##

I&#39;m going forward with the programatic way of injecting the content script, like Google&#39;s example.

### manifest.json ###

    {
        &quot;manifest_version&quot;: 2,
        &quot;name&quot;: &quot;Test&quot;,
        &quot;description&quot;: &quot;Let&#39;s get this sucker working&quot;,
        &quot;version&quot;: &quot;0.0.0.1&quot;,
        &quot;permissions&quot;: [
            &quot;tabs&quot;,
            &quot;*://*/*&quot;
        ],
        &quot;background&quot;: {
            &quot;scripts&quot;: [&quot;background.js&quot;],
            &quot;persistent&quot;: false
        },
        &quot;browser_action&quot;: {
            &quot;default_icon&quot;: &quot;icon.png&quot;
        }
    }

### background.js ###

    chrome.browserAction.onClicked.addListener(function() {
        console.log(&quot;alert from background.js&quot;);
        chrome.tabs.executeScript({file: &quot;jquery-2.0.2.min.js&quot;}, function() {
            console.log(&quot;jquery Loaded&quot;);
        });
        chrome.tabs.executeScript({file: &quot;content.js&quot;}, function() {
            console.log(&quot;content loaded&quot;);
        });
    });

### content.js ###

    console.log(&#39;you\&#39;r in the world of content.js&#39;);
    var ans = {};
    
    ans.createSidebar = function() {
    
        return {
            init: function(){
                alert(&quot;why hello there&quot;);
            }
        }
    }();
    
    ans.createSidebar.init();

I am able to get the first 3 `console.log` statements to show up in the background page&#39;s debugger. I&#39;m also able to get the alert from content.js to show up in any website. But I&#39;m not able to see the `console.log` from content.js, nor am I able to view any of the JS from content.js. I&#39;ve tried looking in the &quot;content scripts&quot; section of the background page debugger&#39;s Sources tab. A few other posts on SO have suggested adding `debugger;` statements to get it to show, but I&#39;m not having any luck with anything. The closest solution I&#39;ve seen is [this post](https://stackoverflow.com/questions/13577330/unable-to-view-content-script-references-in-the-developer-tools-window), but is done by listing the content script in the manifest.

Any help would be appreciated. Thanks!

Debugging Content Scripts for Chrome Extension

I am trying to set a background-image to stretch to the full extent of a `&lt;div&gt;`&#39;s width and height. The `&lt;div&gt;` will be of variable size, so I am using `background-size: cover;`

    background: url(&quot;../images/bkgnd-sidebar.png&quot;) no-repeat left top cover;

I cannot figure out how to place it in this shorthand notation and have it work. If I list each property independently, it works fine, but I was hoping for an all-in-one solution.

This works, but is not preferred:

    background-size:cover;
    background-image:url(&#39;../images/bkgnd-sidebar.png&#39;);

How to include the background-cover value in the shorthand background property?

I want to use an OpenFileDialog object to browse to an excel file. I would like to set the filter to open files with different types of excel extensions like: .xls, .xlsm, .xlsx and so on.

what I am using is this:

    OpenFileDialog of = new OpenFileDialog();
    of.Filter = &quot;Excel Files(.xls)|*.xls| 
        Excel Files(.xlsx)|*.xlsx| Excel Files(*.xlsm)|*.xlsm&quot;;


This works, but the user must select the correct excel file type from the dropdown in the OpenFileDialog.

Does anyone know if there a way to apply one filter for all types of Excel extensions?
 
Something like: &quot;...Excel Files (.xls, .xlsx, .xlxm)|*.xls, *.xlsx, *.xlsm;&quot;  

Thanks in advance for any replies.



Open File Dialog, One Filter for Multiple Excel Extensions?

I want to use an OpenFileDialog object to browse to an excel file. I would like to set the filter to open files with different types of excel extensions like: .xls, .xlsm, .xlsx and so on.
what I am using is this:
<pre><code class="hljs language-scss">OpenFileDialog of = new OpenFileDialog();
of.Filter = "Excel Files(.xls)|*.xls| 
 Excel Files(.xlsx)|*.xlsx| Excel Files(*.xlsm)|*.xlsm";
</code></pre>
This works, but the user must select the correct excel file type from the dropdown in the OpenFileDialog.
Does anyone know if there a way to apply one filter for all types of Excel extensions?
Something like: "...Excel Files (.xls, .xlsx, .xlxm)|*.xls, *.xlsx, *.xlsm;"
Thanks in advance for any replies.

I have a TcpClient which I use to send data to a listener on a remote computer. The remote computer will sometimes be on and sometimes off. Because of this, the TcpClient will fail to connect often. I want the TcpClient to timeout after one second, so it doesn&#39;t take much time when it can&#39;t connect to the remote computer. Currently, I use this code for the TcpClient:

    try
    {
        TcpClient client = new TcpClient(&quot;remotehost&quot;, this.Port);
        client.SendTimeout = 1000;

        Byte[] data = System.Text.Encoding.Unicode.GetBytes(this.Message);
        NetworkStream stream = client.GetStream();
        stream.Write(data, 0, data.Length);
        data = new Byte[512];
        Int32 bytes = stream.Read(data, 0, data.Length);
        this.Response = System.Text.Encoding.Unicode.GetString(data, 0, bytes);

        stream.Close();
        client.Close();    

        FireSentEvent();  //Notifies of success
    }
    catch (Exception ex)
    {
        FireFailedEvent(ex); //Notifies of failure
    }

This works well enough for handling the task. It sends it if it can, and catches the exception if it can&#39;t connect to the remote computer. However, when it can&#39;t connect, it takes ten to fifteen seconds to throw the exception. I need it to time out in around one second? How would I change the time out time?


How to set the timeout for a TcpClient?

I&#39;m trying to understand async await in the simplest form.  I want to create a very simple method that adds two numbers for the sake of this example, granted, it&#39;s no processing time at all, it&#39;s just a matter of formulating an example here.

### Example 1

    private async Task DoWork1Async()
    {
        int result = 1 + 2;
    }

### Example 2

    private async Task DoWork2Async()
    {
        Task.Run( () =&gt;
        {
            int result = 1 + 2;
        });
    }

If I await `DoWork1Async()` will the code run synchronously or asynchronously?

Do I need to wrap the sync code with `Task.Run` to make the method awaitable AND asynchronous so as not to block the UI thread?

I&#39;m trying to figure out if my method is a `Task` or returns `Task&lt;T&gt;` do I need to wrap the code with `Task.Run` to make it asynchronous.

I see examples on the net where people are awaiting code that has nothing async within and not wrapped in a `Task.Run` or `StartNew`.

Do you have to put Task.Run in a method to make it async?

I&#39;ve seen plenty of encryption/decryption tutorials and examples on the net in C# that use the System.Security.Cryptography.RSACryptoServiceProvider, but what I&#39;m hoping to be able to do is:

 - Create an RSA public/private keypair
 - Transmit the public key (or for proof of concept, just move it in a string variable)
 - Create a new RSA crypto provider and encrypt a string with the public key
 - Transmit the encrypted string (or data) back to the original crypto provider and decrypt the string

Could anyone point me to a useful resource for this?

C# RSA encryption/decryption with transmission

How do you make an indeterminate progress bar in a WinForms application? In Silverlight and WPF, you would simply set the ProgressBar&#39;s `IsIndeterminate` property to true. However, this property does not exist in WinForms. How would you create an indeterminate progress bar in WinForms?

How to make an indeterminate progress bar in WinForms?

Consider the below code:

    public class Class1
    {
        public static int c;
        ~Class1()
        {
            c++;
        }
    }

    public class Class2
    {
        public static void Main()
        {
            {
                var c1=new Class1();
                //c1=null; // If this line is not commented out, at the Console.WriteLine call, it prints 1.
            }
            GC.Collect();
            GC.WaitForPendingFinalizers();
            Console.WriteLine(Class1.c); // prints 0
            Console.Read();
        }
    }

Now, even though the variable `c1` in the main method is out of scope and not referenced further by any other object when `GC.Collect()` is called, why is it not finalized there?


Understanding garbage collection in .NET

Form has one Combobox and one ListBox. When the &quot;Add&quot; button is clicked, I want to add the selected item from the ComboBox to the ListBox.

    public partial class MyForm:Form
    {
        List&lt;MyData&gt; data = new List&lt;MyData&gt;();
        private void ShowData()
        {
           listBox1.DataSource = data;
           listBox1.DisplayMember = &quot;Name&quot;;
           listBox1.ValueMember = &quot;Id&quot;;
        }

        private void buttonAddData_Click(object sender, EventArgs e)
        {
           var selection = (MyData)comboBox1.SelectedItem;
           data.Add(selection);
           ShowData();
        }
    }

With this example, the selected item is replaced with the new selection inside ListBox. I need to add the item to the list.

What is wrong with my code?

How to refresh DataSource of a ListBox

The default version of the webbrowser control in a C# [Windows Forms][1]
application is 7. I have changed to 9 by the article *[Browser Emulation][2]*, but how is it possible to use the latest version of the installed Internet Explorer in a webbrowser control?

  [1]: http://en.wikipedia.org/wiki/Windows_Forms
  [2]: http://msdn.microsoft.com/en-us/library/ee330730%28VS.85%29.aspx#browser_emulation


Use latest version of Internet Explorer in the webbrowser control

I want to write something like this `C:\Users\UserName\Documents\Tasks` in a `textbox`:

    txtPath.Text = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)+&quot;\Tasks&quot;;

I get the error: 

&gt; Unrecognized escape sequence. 

How do I write a backslash in a string?


Content Type	Original Author	Original Content on Stackoverflow
Question	netcat	View Question on Stackoverflow
Solution 1 - C#	Odys	View Answer on Stackoverflow
Solution 2 - C#	Bence Végert	View Answer on Stackoverflow

Open File Dialog, One Filter for Multiple Excel Extensions?

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

How to include the background-cover value in the shorthand background property?

Debugging Content Scripts for Chrome Extension

Attributions