Delete project from TFS 2012

If you have ever used TFS, you can create a new project from Visual Studio directly. However, to delete a project, you need to use Team Foundation Server Console in a remote server which is not available in sometimes such as https://tfs.visualstudio.com/. You cannot access the server directly. So, the solution is we need to access remotely using command line tool from Visual Studio.
- Open Developer Command Prompt for VS2012
- The syntax command is TFSDeleteProject [/q] [/force] [/excludewss] /collection:URL TeamProjectName
- Example: TFSDeleteProject /collection:"https://xxx.visualstudio.com/DefaultCollection/" "Project X"

Change IE security setting to normal in Windows Server 2012

By default Internet Explorer (IE) in Windows Server is protected with some security to prevent unintentionally attacked during browse internet. Sometimes, we want it to be just a normal IE that trusts how user use it. In order to do that in Windows Server 2012 is described as follows:

Firstly, opens Server Manager page.

Next, on the top of Dashboard under welcoming message, clicks at "Configure this local server" as shown picture below.

Then, on properties tab, you will see information is divided into 2 sides. Look at the right side. You will see "IE Enhanced Security Configuration", it should be on if your IE is still protected. So, we gonna change it off. by click at it.

After you click it, a popup will be opened. Your job is changing to off as shown below.

Click OK and wait for a while during system setting is changing. When it finished, you will notice on properties tab "IE Enhanced Security Configuration" is changed to Off.

Remove Remote Desktop Entries from Remote Desktop Connection

Steps to remove are described as follows:

1. Click start or press Windows button, it will show application screen.
2. Type "regedit", it will search and show only one program.
3. Select that "regedit.exe".
4. On the left hand side of the program, it is a navigation panel. Then you can easily navigate to "HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\Default".
5. On the right hand side of the program, they are entries of all connection Remote Desktop Connection remembered. In order to remove an entry, just select which connection you want to delete using right click at its name then select delete command. It will automatically remove (no need to save again).

Reference: http://support.microsoft.com/kb/312169

AutoResetEvent to synchronize threads

Sometimes when we are dealing with multithreading application, we need to lock some threads and waiting for another thread finished execution, in order to do that it needs some lock mechanism to lock other threads . So, in this post we have a solution that we can use AutoResetEvent class to block threads from execution. AutoResetEvent is a class to control lock mechanism and guarantee that after it is set, it will allow only one thread to continue, then reset automatically (become lock again). There is also another class named ManualResetEvent, which it concept is similar to AutoResetEvent class, however, the difference is we need to reset the lock mechanism manually. So, it means that it will allows threads at the same time to continue until we tell it to stop (reset it). By the way, in this post I would like to talk about AutoResetEvent class only. The usage scenario for this class is easy to follow as described in the following website:

References:

• http://msdn.microsoft.com/en-us/library/system.threading.autoresetevent.autoresetevent.aspx
• What is the difference between ManualResetEvent and AutoResetEvent in .NET?

Task the new way to parallel jobs, a replacement for BackgroundWorker

Task class is an improvement version for BackgroundWorker. It supports nesting (parent/child tasks), new cacellation API, task continuations, etc. The following website is an example to compare Task and BackgroundWorker.

References: 

• Reporting Progress from Tasks
• Task parallel library replacement for BackgroundWorker?
• Continuation Tasks
• Parallel Programming: Task Schedulers and Synchronization Context

Image POST Client and Sever in Python and C#

From last time, I had told how to encode image into base64 string[1], and how to do POST message to HTTP server[2][3] This post will continue from those posts. First, we will create HTTP POST server in Python. I based on the concept that a message will be encoded using url-encode format in a form of base64 string, and the image string will be sent to a variable named "img". It will decode an image string from that variable.

import SimpleHTTPServer
import SocketServer
import cgi
from base64 import decodestring

PORT = 8000

class ServerHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):

 def _writeheaders(self):
  self.send_response(200)
  self.send_header('Content-type', 'text/html')
  self.end_headers()

 def do_GET(self):
  filename = 'temp.png'
  f = open(filename, 'rb')
  encode = f.read().encode('base64')
  img = '<img height="200" src="data:image/png;base64,' + encode + '" width="250" />'
  self._writeheaders()
  self.wfile.write("""
  <html><head><title>Simple Server</title></head>
   <body>
    It worked!!!!
 
    %s
   </body>
  </html>"""  % (img))
 def do_POST(self):
  form = cgi.FieldStorage(
   fp=self.rfile,
   headers=self.headers,
   environ={'REQUEST_METHOD':'POST',
      'CONTENT_TYPE':self.headers['Content-Type'],
     })
  encode = form['img'].value
  decode = decodestring(encode)
  output = open('temp.png', 'wb')
  output.write(decode)
  output.close()
  # After posting image has done, it will response GET message to show that image
  self.do_GET()

Handler = ServerHandler

httpd = SocketServer.TCPServer(("", PORT), Handler)

print "serving at port", PORT
httpd.serve_forever()

Then, we will create HTTP POST client to upload an image to our HTTP POST server.

Python:

import urllib, urllib2

uri = 'http://localhost:8000'
filename = 'Leafa.jpg'
f = open(filename, 'rb')
encode = f.read().encode('base64')
params = { 'img' : encode }
data = urllib.urlencode(params)

p = urllib2.urlopen(uri, data)
print p.read()

C# WPF:

string fileName = "Leafa.jpg";
StreamResourceInfo sri = null;
Uri uri = new Uri(fileName, UriKind.Relative);
sri = Application.GetResourceStream(uri);

using (var memoryStream = new MemoryStream())
{
    sri.Stream.CopyTo(memoryStream);
    byte[] result = memoryStream.ToArray();
    var base64 = "img=" + HttpUtility.UrlEncode(System.Convert.ToBase64String(result));

    MessageBox.Show(base64);

    using (var wc = new WebClient())
    {
        wc.Headers["Content-Type"] = "application/x-www-form-urlencoded";
        wc.UploadStringCompleted += wc_UploadStringCompleted;
        wc.UploadStringAsync(new Uri(url), "POST", base64);
    }
}

The server will response a web page, which the client will show that response as a text format, so, if you want to make sure that your image are already uploaded, just check it the "server.py" directory. You will see the image named "temp.png", which is converted from jpg image in the client side. Moreover, you can use a web browser request to http://localhost:8000 to let GET response show you that uploaded one.

The sample project is uploaded, can download from http://www.mediafire.com/?1okv3lc6nk1jsc7.

Leafa.jpg

References:

1. Encode an Image into base64 string in C# / Python
2. Simple HTTP POST Server / Client with Python
3. HTTP POST data via WebClient and WebRequest

STA and MTA

This post is written because when I wrote the multithreads application, mostly in UI contained apps, it will ask for using STA in some methods. Then, I really curious what it is and find out why need to use STA, and how about MTA. In short, STA and MTA indicates where the thread resources will be located. If some objects need like COM objects, they are not thread safe which don't handle thread synchronization, commonly used in UI compoment. To call COM objects in other threads, they need to marshal message to the STA thread using message pumping system.

References:

• http://stackoverflow.com/questions/127188/could-you-explain-sta-and-mta
• http://bytes.com/topic/c-sharp/answers/260741-difference-between-sta-mta
• http://en.wikipedia.org/wiki/Component_Object_Model
• http://en.wikipedia.org/wiki/Object_Linking_and_Embedding
• http://en.wikipedia.org/wiki/Marshalling_(computer_science)

Distributed Caching in ASP.NET

The following links provide the concept of doing distributed caching and also their benefits:

• How to Handle Relational Data in a Distributed Cache
• Distributed Caching On The Path To Scalability

Windows Azure Errors Guide

If you face provisioning timed out during restore virtual machine from image file: Azure (IaaS) Provisioning Timed Out.

If you face the provisioning operation is too long, look at "The operation cannot be performed because the virtual machine is faulted."

P.S. If I find anymore unexpected errors, I will update to this post.

Useful Links for XNA Novice Startup

This link will guide from the loading resource files to animating multiple sprite objects: http://www.xnadevelopment.com/tutorials.shtml

This link will give a set of sample walkthrough projects to let us follow: http://www.riemers.net/