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Cross Page Posting and Exceptions in ASP.NET Page



HTMLForm.SubmitDisabledControls = true; will disable the controls while the page is being submitted.

One Server Side Visible HTMLForm is supported in a Web Page. Other Form <form> tags should client side only with action=”search.aspx” and method=”post” attributes. And for the fact one will have to use old fashioned code to retrieve values:

string textToSearch = Request.Form["Keyword"].ToString();

In CrossPagePostback Specify the PostbackURL for <asp:Button> in which following script will be written to postback to a different page:

In this case a new hidden field will be generated __PREVIOUSPAGE to provide viewstate information of previous page.

CrossPagePosting is a two way process in which Source page first postsback to itself then to the Target page specified in PostabkURL.

Detecting CrossPagePostback:
          if (PreviousPage == null)
{
          if (!PreviousPage.IsCrossPagePostBack)
{
Response.Write("Sorry, that's the wrong way to invoke me.");
Response.End();
return;
                   }
}
If PreviousPage contains validators then use:

if (!PreviousPage.IsCrossPagePostBack)
{
}

In case of Server.Transfer to obtain previous page in ASP.NET 1.x use:
            Page caller = (Page) Context.Handler;

But in ASP.NET 2.0 &+ PreviousPage can be used and <@% PreviousPageType %> can used for strongly type access. But in case of Server.Transfer IsCrossPagePostBack is set to false.

Exception Handling:
Showing a custom page for all exception and showing a specific page on a specific error code:

<configuration>
<system.web>
<customErrors mode="On" defaultRedirect="/GenericError.aspx">
<error statusCode="404" redirect="/ErrorPages/Error404.aspx" />
<error statusCode="500" redirect="/ErrorPages/Error500.aspx" />
</customErrors>
</system.web>
</configuration>

Path to the page is passed through the Query string to exception handling page that can be retrieved as:
                   Request.QueryString["AspxErrorPath"];
To Write Trace information to other listeners that are registered in <System.Diagnostics> Sections.

Personalization:
          ProfileModule is responsible for loading information from the Storage Medium and making them available.

To load a different profile, handle the Profile_Personalize method in global.asax.

void Profile_Personalize(object sender, ProfileEventArgs e)
{
          ProfileCommon profile = null;
profile = (ProfileCommon) ProfileBase.Create("Guest");

// Make the HTTP profile module use THIS profile object
if (profile != null)
e.Profile = profile;
}


Writing Custom Profile Provider:
         http://msdn.microsoft.com/msdnmag/issues/07/03/ASPNET2/default.aspx

One can use a different provider for each property as shown:

          <properties>
                   <add name="BackColor" type="string" provider="MyProvider" />
                   <add name="TabSettings" type="string" provider="SqlProvider" />
</properties>
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