Accessing template elements of a usercontrol

Hi Frnds,
In the last post I explained of creating a user control which acts like a container. In this post I will explain how to change the properties of your user control. The following steps will clear you about this,
1. Create a public property for the user control, accessing on which you will change the properties of your usercontrol. This is something like,
Private string someText;
Public string SomeText
{
Set { this.txtName.Text = value; }
Get { return txtName.Text; }
}
2. Since your properties are kept inside control template you cannot refer them simply by name as above.i.e.,this.txtName is not accessible if txtName is name of an element inside the control template.To access that element you need to have something like,
TextBlock txtBlock = (TextBlock)Template.FindName(“txtName”,this);
So if you think of something like,
Set
{
TextBlock txtBlock = (TextBlock)Template.FindName(“txtName”,this);
txtBlock.Text = value;
}
Then you are mistaken. This is because inside the setter you cannot fill the object txtBlock. This means that you will get a null reference when you run the above code. The reason is control hierarchy loading. When your setter method is executing your TextBlock is not yet created and so it will return an error(a run-time error).So the solution would be to set the value inside onApplyTemplate().The overall code looks like this:
MyUserControl.xaml
<USerControl x:Class="MyUserControl" Height="Auto" Width="Auto"......>
<UserControl.Template>
<ControlTemplate>
<Grid>
<Border Height="Auto" Width="Auto" Background="{TemplateBinding Property=ContentControl.Background}" CornerRadius="10" Name=”myContainer”>
<ContentPresenter Content="{TemplateBinding Property=ControlContent.Content}" />
</Border>
</Grid>
</ControlTemplate>
</UserControl.Template>


MyUserControl.xaml.cs
Public partial class MyUserControl : UserControl
{
Public MyUserControl()
{
InitializeComponent();
}
Public override void OnApplyTemplate()
{
Border border = (Border)Template.FindName(“myContainer”,this);
border.CornerRadius = new CornerRadius(topLeftRadius,0,10,0);
base.OnApplyTemplate();
}
Private double topLeftRadius;
Public double TopLeftRadius
{
Set { topLeftRadius = value; }
Get { return topLeftRadius; }
}
}


And in the main window Main.xaml
<Window…….>
<MyUserControl Background=”Chocolate” Height=”100” Width=”65” TopLeftRadius=”20”>
<TextBlock HorizontalAlignment=”Center” VerticalAlignment=”Center”>Some Text </TextBlock>
</MyUserControl>
</Window>

Please feel free to scold me if anything wrong mentioned.
Hope this was helpful

Creating UserControl to hold other controls in WPF

Hi Friends,
You can find many samples in google for creating user controls and my post stands little adhead of them.
Firstly if you create a user control and in the main window where you use the usercontrol, if you try to put some content within your usercontrol, it will throw an error. This is because your usercontrol is not designed to handle other wpf elements within it. To make this happen you have to follow a different apporach.
The following is a sample code for creating such a control:
<USerControl x:Class="MyUserControl" Height="Auto" Width="Auto"......>
<UserControl.Template>
<ControlTemplate>
<Grid>
<Border Height="Auto" Width="Auto" Background="{TemplateBinding Property=ContentControl.Background}" CornerRadius="10">
<ContentPresenter Content="{TemplateBinding Property=ControlContent.Content}" />
</Border>
</Grid>
</ControlTemplate>
</UserControl.Template>

And in your main window just add it as
<MyUserControl Background="LightBlue" Height="50" Width="75">
<Button content="Push Me">
</MyUserControl>

Remember here both MyUserControl and the Main window remain in the same namespace. The result of the above code will be a rounded rectangle with a button inside it. Creating a rounded rectangle as an usercontrol is easy but it will not act like a container for holding for other elements. What the magic i have done here is, i've defined the look of my usercontrol as rounded rectangle inside the usercontrol template and mainly the ContentPresenter Tag which makes the control to hold other items. Other important issue to look at is the TemplateBinding. I will not explain about TemplateBinding for now but you can find many sites that will help you around.
In my next post i'll explain how to change/access the cornerradius of the rectangle from code-behind of the usercontrol which will help you to expose the accessibility to the main window.

Double-click solution file to create your web site

Hi all,
In Visual Studio, if you have to go for any web based content you will be left with two choices - web site/web application. Here is one difference that may be helpful for your selection criteria:

1. Create a solution file.
2. Add a new project and select the project type as "Asp.Net Web Application".
3. Right click on this web application and select properties - go to 'Web' tab, under server you will find the radio box 'Use Visual Studio Development Server' selected. Below that is the radio box 'Use Local IIS Web server'. Uncheck the former and select the later one.
4. Now when you export your solution file to another machine and when you double-click the solution file, your web site is automatically created in the IIS Server of that machine.

If you select a new web site to be added to your solution file then you won't find such an option as described above. So if you have a web site added to your solution file and when you open the solution file in another machine, the default url will be something like 'http://localhost/MySite/MyPage.aspx' and this means a site located in that machine. But since you don't have any such site published in IIS yet, your visual studio will warn you about this and the project will be unavailable.

Difference between Raster Image and Vector Based Images

Hi All,
In differentiating the two kinds of images what i conclude is "Vector based images are mathematical images - this implies that these are image format used by computers. This is true because a raster image has definition defined pixel by pixel.
For a better understanding pls go through the following link:
http://www.nw-media.com/photography-articles/31/raster-vs-vector/

ADO.NET Entity Framework and Linq Framework

I googled for this and i have found the following links which will clear many confusions 

http://msdn.microsoft.com/en-us/library/cc161164.aspx

http://dotnetaddict.dotnetdevelopersjournal.com/adoef_vs_linqsql.htm

http://social.msdn.microsoft.com/forums/en-US/adodotnetentityframework/thread/55a7a796-2bef-4df9-b858-2f9804d39af5/

http://dotnethitman.spaces.live.com/blog/cns!E149A8B1E1C25B14!195.entry

Please go thru these links once.

Writing Your Own HttpHandler

Hi All,

Today i'll explain how to write our own handler for a new kind of page. Firstly, Handlers(as the term explain) are for handling things. These things are client requests. So for a client request to Default.aspx there will be a handler. This will be a default handler which will ship along with asp.net runtime. If you have new kind of extension you can writer your own handler.

The reason of writing this blog is for a good understanding of http handlers. I insist you to follow these steps and create your own handler. I have followed these procedures from the site:

http://www.15seconds.com/Issue/020417.htm

Step 1:

In u r VS, create a new c# class library and the name the class as MyOwnHandler.

The code should be

using System;

using System.Web;

using System.Text;

namespace MyCustomizedHandler

{

  public class MyOwnHandler: IHttpHandler

  {

     public MyOwnHandler()

     {

     }

      #region for implementing HttpHandler

      Public void ProcessRequest(HttpContext context)

      {

         HttpResponse responseObject = context.Response;

         responseObject.Write("<html><body><h1>My Customized page</h1>");        

 responseObject.Write("</body><html>");

       }

       Public bool IsReusable

       {

            get

            {

                  return true;

            }

       }

       #endregion

      }

  }

}

Rather than copying and pasting i insist all of u to type this small piece of code manually. Now just compile this from ur VS and paste the output of this dll into a virtual folder webapplication. I have a website in my iis with the name 'jsonSamples', so i placed the dll output of the above code into the bin directory of 'jsonSamples'. 

Step2: 

Now open the web.config file of the webapplication(in my case 'jsonSamples') and add the following piece of code inside it:

<httpHandlers>

     <add verb="*" path=".sample" type="MyCustomizedHandler.MyOwnHandler,       MyCustomizedHandler">

</httpHandlers>

Step3:

All what we have done is in the application level. i.e., our application knows how to render a request for the page type .sample. Now we have to tell this to the iis webserver also. For that we have to do:

Launch IIS, right click on Default Web Site, go to home directories tab, click on configuration. This will open a new window. Now click on the add button and in the Executable section give the url of the aspnet_isapi.dll. Down to it, the extension should be given as 'sample'.

Click all ok's and close the window.

Now from ur browser just make a request some thing like this:

http://localhost/jsonSamples/helllo.sample

http://locahost/jsonSamples/239kshrkweh.sample

http://localhost/jsonSamples/anything.sample

You should get the output. (But i didn't get the output for the first time)

If u dont get the output then dont panic, just open ur webapplication(jsonSamples) in VS and for it add reference of u r class library dll. Even though u have placed the dll in the bin directory of the webappliation but u need to do add reference to the same item once again from VS. I dont know why but it works.

Hope this helped.

Improve u r english

Hi Friends,

I have found a site that help u improving u r english skills. It was really helpful for me. May be u should also  take a look at it.

 

http://www.pandorabots.com/pandora/talk?botid=f5d922d97e345aa1