Team Foundation Server is not your current source control plug-in

If you have TFS installed on your machine as your source control provider, and for some reason, it is not being selected as the default source control in Visual Studio everytime you open a solution and it forces you to always pick the source control plugin (from Tools -> Options -> Source Control), it could possibly be due to the following reasons:

1. The existing solution that you have created probably has references to an old source control provider (like VSS) and this could prevent it from resolving.

2. You may have checked in all your projects but you may not have checked in your solution. (TFS does not pick this automatically when you checkin the files). You can quickly verify if this is the case by looking for the lock icon adjacent to the filename in the Solution Explorer. If you do not see a lock icon, right click on the solution and you should see a "Add to Source Control.." option. Doing this will fix the issue.

In some cases in scenario 2, it might complain that binding already exists and you should actually update this via "Change Source Control..". If so, click on the solution, then go to File -> Source Control -> Change Source Control.., specify the TFS server for the underlying projects/solution and this should do the trick.

If it does not allow you to specify the server, then set TFS as source control either by going to Tools -> Options -> Source Control or by clicking on the link that says "TFS is not your default source control". After setting TFS as source control, go to File -> Source Control -> Change Source Control and click on Bind. This will cause a checkout of the files and you will now be able to view the files as sourced under TFS.

 If none of these work, you may probably want to look up on this forum

http://social.msdn.microsoft.com/Forums/en/tfsversioncontrol/threads

Good Luck!,

Satish

Vista problems on MacBook Pro

Recently I installed Vista on MacBook Pro using the Bootcamp http://www.apple.com/macosx/bootcamp/

Everything was working awesome and I love the Mac. Then I started running into "Vista" problems. Everytime I closed my laptop and left it unattended for a couple of hours and started up Vista from it's "Resuming Windows" mode, it would freeze up. I would have to do a hard start but even after that, after logging in, it would freeze again, causing me to do a hard-start again. Frustated with this, and having not found any solution, I suspected my Vista install could be the culprit (none of my colleagues were having this issue), and so tried to do an upgrade install of Windows Vista (popped in the Vista install CD and let it do it's job). After 6 agonizing hours of reinstalling Vista, I log into Windows and this is where my troubles begin:

I already had some software installed and since I opted for upgrade instead of clean install of Vista, it seemd to have corrupted some registry settings and it messed up the following applications:

• Daemon Tools http://www.daemon-tools.cc/dtcc/announcements.php
• Input Remapper http://www.olofsson.info/
• Kaspersky Antivirus http://www.kaspersky.com/

I tried to uninstall them but that wouldn't work either. So I did an install on top of them and then uninstalled and reinstalled again. Finally got them working.

Word of Advice: If you plan to follow the route that I have taken, definitely uninstall the above apps and install them again, esp Input Remapper as it relies on the Mac Windows Drivers of Bootcamp.

Finally, I am good to go, my Vista seems stable and everything seems happy until I notice some nagging problems.

My audio device doesn't work anymore. It says: "No audio output device is installed". Installing/Reinstalling Bootcamp drivers didn't help. The only way I found to get this resolved is this:

• Open Device Manager
• Go to "Sound, video and game controllers"
• Uninstall Sigma Tel High Definition Audio CODEC. In the popup, choose the "Remove install software".
• Reinstall Bootcamp Window Drivers again

And lo! It works!

The other problem I ran into is "no battery is detected".

Even when I plugged out the power cord, it runs fine but I wasn't sure how long it would last. It would not give any metrics if I hovered over the Battery icon. The solution to this is:

• Start your computer and go to OSX
• Reinstall Bootcamp in OSX.
• Reboot your machine and login to Vista.

Your battery meter will now display properly.

Hope this helps other folks who run into the same issues I've had.

Have fun,
Satish

Clarity Consulting

Role of DockStyle property when adding controls

I recently ran into scenario where I had to rearrange some controls in an existing form. In a form, I had a splitter, topGrid and bottomGrid. The DockStyle for topGrid was set to Top, for splitter, it was set to top and for bottomGrid it was set to Fill. I had to change the dockstyle of topGrid to Fill and bottomGrid to bottom. As soon as I changed it, the topGrid would span the whole form and thus, I could not see a part of it. I had no idea why this was happening. I tried different things like updating the values in the code (and not in design mode). I even switched the grid positions to see if something was wrong with the layout itself but the bottomGrid always worked fine and seemed to stick to it's position.

   I almost gave up and was on the verge of putting them in separate panels when I realized that this weird behavior is being caused by the order the controls were added to the form. The control that is added last takes the topmost priority. And when I looked in the generated code, sure enough, the topGrid was the last one added and hence whenever I set it's DockStyle to Fill, it would occupy the whole grid and then the other controls would be added on top of it.

So I went into the generated code and manually rearranged the order in which controls are added and it worked exactly as I wanted.

You can find more info at:

http://www.bluevisionsoftware.com/WebSite/TipsAndTricksDetails.aspx?Name=DockStyle

http://msdn2.microsoft.com/en-us/library/system.windows.forms.dockstyle.aspx

Happy Coding!

Sending Http Authentication Request from a Windows Form

If you need to perform authentication using HttpWebRequest from a Windows application, you can do it the following way:

// Prepare the data that needs to be sent

string postData = "userID=" + HttpUtility.UrlEncode(userID);

postData += "&password=" + HttpUtility.UrlEncode(_password);

byte[] data = ASCIIEncoding.ASCII.GetBytes(postData);

// Prepare web request

HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(myURL);

// Add the required headers

webRequest.Method = "POST";

webRequest.ContentType = "application/x-www-form-urlencoded";

// Since we are sending data, specify the content and write to the stream

webRequest.ContentLength = data.Length;

Stream newStream = webRequest.GetRequestStream();

// Send the data.

newStream.Write(data, 0, data.Length);

newStream.Close();

// Retrieve the response

HttpWebResponse webResponse = (HttpWebResponse)webRequest.GetResponse();

XmlTextReader reader = new XmlTextReader(webResponse.GetResponseStream());

XmlDocument doc = new XmlDocument();

doc.Load(reader);

// And then read the XmlDocument

The above immplementation is pretty straightforward. If you plan to send the credentials in the header, you can use Basic Authentication. This should only be used when sending the request over SSL as the information is still sent openly. Using SSL ensures that the contents of this request are encrypted. This can be done in the following way:

//Prepare the Authentication parameters

String auth = userID + ":" + password;

byte[] binaryData = Encoding.UTF8.GetBytes(auth);

auth = Convert.ToBase64String(binaryData); // Using base64 encoding

auth = "Basic " + auth; //This specifies it to use Basic Authentication

// Prepare web request

HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(myURL);

// Add the standard headers

webRequest.Method = "POST";

webRequest.ContentType = "application/x-www-form-urlencoded";

webRequest.ContentLength = 0;

// Add this additional header

webRequest.Headers[“AUTHORIZATION”] = auth;

HttpWebResponse webResponse = (HttpWebResponse)webRequest.GetResponse();

XmlTextReader reader = new XmlTextReader(webResponse.GetResponseStream());

XmlDocument doc = new XmlDocument();

doc.Load(reader);

This is a more secure call!

You can find more information about HttpWebRequest and Headers at:

http://msdn2.microsoft.com/en-us/library/system.net.httpwebrequest.aspx

http://msdn2.microsoft.com/en-us/library/system.net.httpwebrequest.headers.aspx

Suppressing Script Errors in a WebBrowser

Previously in the .Net Framework 1.0, I was using the COM version of the WebBrowser and I used the AxWebBrowser. For users who are still using this reference, the suggested way for suppressing the script errors is documented here:

http://support.microsoft.com/?kbid=279535

However, I migrated recently to .Net Framework 2.0 and I now use the System.Windows.Forms.WebBrowser which comes as a part of this framework. This control now has a property namely ScriptErrorsSuppressed which will disable any error dialogs when set to true. A note of caution though: The above property will not only suppress script errors but any errors that originate from the underlying ActiveX control.

If you need control of the error that has occurred and play around with the parameters/error, a better way to do is by using the DocumentCompleted Event.

Here is a sample code of how I implemented:

// Register the event

        private void SetBrowserSettings()

        {

            _webBrowser.DocumentCompleted +=new WebBrowserDocumentCompletedEventHandler(_webBrowser_DocumentCompleted);

        }

// Handle the event

          // Invoked after the document has completed loading

        void _webBrowser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)

        {

            ((System.Windows.Forms.WebBrowser)sender).Document.Window.Error += new HtmlElementErrorEventHandler(Window_Error);

        }

          // Handles any errors that occur after the document has loaded

        private void Window_Error(object sender, HtmlElementErrorEventArgs e)

        {

            MyLog(LogLevel.Error, "Script error occurred at URL {0}, Line Number {1}. Description {2}", e.Url, e.LineNumber, e.Description);

            // Ignore the error and suppress the error dialog box.

            e.Handled = true;

        }

You may also use the Navigated event in a similar fashion. But be aware that if the user hits the refresh button, this event will not be invoked again. So depending on your requirement, you can implement it either way

You can also find further enhancements to the WebBrowser control discussed here:

http://www.codeproject.com/csharp/ExtendedWebBrowser.asp?df=100&forumid=285594&exp=0&fr=26

ASP .NET Datagrid with scrollbars and fixed headers

http://www.dotnetjunkies.com/HowTo/E833AEAE-8D7E-4D1F-821B-D848D965F70A.dcik

http://blogs.claritycon.com/blogs/kevin_marshall/archive/2006/02/23/234.aspx

Dummy tables for SQL in Oracle, MS SQL and DB2

http://asktom.oracle.com/pls/ask/f?p=4950:8:::::F4950_P8_DISPLAYID:1562813956388

Unable to start debugging on the Web server

Unable to start debugging on the Web server

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vsdebug/html/vxtbshttpservererrors.asp

Failure to start monitoring changes / Unable to start debugging on the web server

• Check who is running the aspnet_wp.exe by looking at the processes in Task Manager. It is ASPNET by default. Lets verify if this user has been given permissions to access C:\Inetpub\wwwroot\MyApp
• In Windows Explorer, right click on this directory, click Properties.
• Select Security Tab and if the ASPNET user does not exists, click on Add and add the user.
• Leave the default permission and click OK to save these changes.
• If the problem persists, repeat these steps for each folder in the hierarchy of the path.
• Run your ASP .Net application now and it should work.

• Verify that the debug property is set to true in the web.config file.
• Give full read-write permissions to the respective folders
• Verify that IIS server was installed prior to ASP .NET.
• Run aspnet_regiis.exe -i and reinstall the relevant ASP .NET version.

The Active schema does not support the element DisplayLayout, AddNewBox, Bands etc..

Select FIRST/TOP N rows in MS SQL, Oracle and DB2

How do you select the first N rows in various databases?

A quick thing to remember is that rows are not stored in any particular sequence in a database. They can be placed in random data blocks in the database without any order whatsoever. If a query returns X rows, they definitely do not mean that these rows are stored in exactly this same order. It is just that these rows have satisfied your select query and are being displayed in the order they are found (unless you specify an ORDER BY clause). So how do I obtain only the first N rows from a query which actually returns more than N rows?

Here is a quick overview of how it can be done.

MS SQL

The above query will return the first 10 rows sorted by name. How do I get the bottom 10 rows? Use the DESC keyword in the ORDER BY clause and it will sort it in reverse order.

ORACLE

One has to be careful when trying a similar thing in ORACLE. The above code will not work, simply because the query will return the first 10 rows and then order them, which is definitely not what you wanted. ROWNUM is a pseudo column that is assigned values based on the results returned. So the above code would have worked if there was no ORDER BY clause. The right way would be:

A good resource for various questions on Oracle is:

http://www.orafaq.com/

DB2

Customizing columns in ASP.Net DataGrids

   Working with datagrids can be fun and interesting and sometimes challenging too. Everything is fine as long as you are using the basic features of Datagrid and generating the columns from the dataset itself. But they tend to get a little challenging when you need to customize columns and design it the way you want and provide more customization that is not available in the DataSet itself.

   This article discusses some key scenarios when dealing with Datagrid.

1. Custom Column formatting

   Now all columns need not be of the same datatype or you may want to format a certain numeric column to display commas etc. So how can we do it?

   i.   Specifying the DataStringFormat

   Before I delve into the different formats, here is how you can add/change the format. Right click on the Datagrid in design view and click on Property Builder (or in the Datagrid properties, click on the Columns Collection).
 
   Choose the Columns tab. You will see a list of Available Columns and Selected Columns. If you don’t have any selected columns, add a Bound Column. Now click on the selected Column and you will see the option for “Data Formatting expression”. This is how you enter the data format.
 
   You can also directly add this attribute to the aspx code which you is discussed later in this article.

   The single-most important rule to understand is the way the format specification. The specification is:
   {0:myFormat}   where myFormat is the format you want to specify, for example
   {0:C}

   People often forget the curly braces 0 i.e. {0}. YOU NEED THIS EVEN IF YOU ARE ENTERING IT THROUGH PROPERY BUILDER
 
   The {0} specifies the current row and cell to which the format needs to be applied to.

   ii.   Various formats

         a.   Currency format
                  {0:C}
                  The currency format is according to the culture info set in the web config file

         b.   Numeric format
                  {0:000}
                  This specifies zero padded numbers of length 3

         c.   Decimal format
                  {0:0.00}

                  You can find more info about standard numeric formats at:
                     http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconstandardnumericformatstrings.asp

                  and custom numeric formats at:
                  http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconcustomnumericformatstrings.asp

         d.   Date format
                  {0:dd-MMM-yyyy HH:mm:ss}

                  You can find more standard date formats at:
                  http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconstandarddatetimeformatstrings.asp

                  and custom date formats at:
                  http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconcustomdatetimeformatstrings.asp

   iii.   Modifying the format of the custom column in the ASPX page

            You can add the DataFormatString attribute directly in the aspx page as shown below:
     
            <asp:BoundColumn DataField="LOGDATE" HeaderText="Log Date" DataFormatString="{0:yyyy/MM/dd HH:mm:ss}"></asp:BoundColumn>

2. Adding a Row Number to your Datagrid

         You are displaying a ton of rows in your custom datagrid and you wish you could have a row number to identify each row easily. How do we do that?

         It is very simple actually. By using a template column. (For info on how to create template columns, refer to the links below in this section).

         In the ItemTemplate element, you can define the content that will be rendered for each item in the column.

         Below is the sample for this:

      <asp:templatecolumn headertext="Row Number">
         <itemtemplate>
            <%# Container.ItemIndex+1 %>
         </itemtemplate>
      </asp:templatecolumn>

         ItemIndex is the row index indexed from 0. So add 1 to it and you get your row numbers!!

         Now an interesting point to note is the Container object which basically refers to the current row in the DataGrid and is of type DataGridItem. So you can practically use any methods defined on the DataGridItem and utilize them in displaying values in your column, and this is how we have displayed the row number. You can invoke the Container.DataItem to get the row itself and you can choose whichever column you want from it by using DataBinder.Eval(). An example is discussed in the later section.

         There is a good article on creating templates at:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vbcon/html/vbtskaddingtemplatecolumntodatagridwebcontrol.asp
 
A very good article on the usages of template columns can be found at:

http://aspnet.4guysfromrolla.com/articles/061002-1.aspx

3. Adding a HyperLink column to your Datagrid

      This is pretty simple thanks to the customizable columns. You can do it in 2 ways (that I know of):

i.   Using HyperLinkColumn

      Using the property builder, you can add a HyperLinkColumn and specify the URL that it needs to point to. You can add other attributes like target location, the Header Text etc. Here is a sample:

<asp:HyperLinkColumn
         Target="_blank"
         DataNavigateUrlField="ID"
         DataNavigateUrlFormatString="Form2.aspx?MyID={0}"
         DataTextField="ID"
         HeaderText="Details" >
</asp:HyperLinkColumn>

• The DataTextField is the column to be displayed. (If you don’t want to display this value but put in a common value of let’s say “More Info” to each cell, you can do this by specifying it in DataFormatString, for example DataFormatString=”More Info”)
• The DataNavigateUrlField contains the column name that is to be passed into the URL field.
• The DataNavigateUrlFormatString contains the URL link.
• The HeaderText refers to the Column name to be displayed

ii.   Using TemplateColumn

         You can achieve the same by adding a template column and putting in  <a> attribute. Consider this example:

<asp:TemplateColumn HeaderText="Row #">
   <ItemTemplate>
       <a target=_blank href='<%# DataBinder.Eval(Container.DataItem, "ID", "Form2.aspx?MyID={0}") %>'><%# Container.ItemIndex+1 %></a>
    </ItemTemplate>
</asp:TemplateColumn>

DataBinder.Eval takes in 3 parameters:

• Container.DataItem is the current DataGridItem the grid is referring to.
• ID is the column you want to choose from the DataGridItem row
• The third parameter is the format that you want to display the column value. By saying Form2.aspx?MyID={0}, I am actually sending the value of ID into the format string and using that as my link URL.

Notice how neatly we have tricked it to display the row number and the hyperlink being the format string we want to use, which is a URL to another page

You can use the same method to display images in a grid. For example:

 <itemtemplate>
         <img width=60 align="top" src='<%# DataBinder.Eval ( Container.DataItem, "Book_Cover", "/etc/images/cover-{0}.gif" ) %>' >
</itemtemplate>

Do note that DataBinder.Eval performs late bound evaluation and may cause slow performance compared to standard ASP.NET pages. Refer to this link here for more details:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemwebuidatabinderclassevaltopic2.asp

Hope you had fun reading through this and found this article helpful.

Happy Programming!!
 
Satish Vemula
Clarity Consulting
svemula@claritycon.com