TagPrefixCollection Class

The TagPrefixInfo class allows you to programmatically access and modify tag-prefix information stored in a configuration file. Tag prefixes associate a "namespace" in ASP.NET with the assemblies and namespaces that must be included for custom controls and user controls to work properly.

TagPrefixInfo objects are stored as members of a TagPrefixCollection object. The TagPrefixCollection class allows you to programmatically access and modify the controls subsection of the pages section of a configuration file.

The following configuration file excerpt shows how to declaratively specify values for several properties of the TagPrefixCollection type.

<system.web>
  <pages>
    <controls>
      <clear />
      <remove tagPrefix="MyTags" />
      <!—- Searches all linked assemblies for the namespace -->
      <add tagPrefix="MyTags1" namespace=" MyNameSpace "/>
      <!-- Uses a specified assembly -->
      <add tagPrefix="MyTags2" namespace="MyNameSpace" 
        assembly="MyAssembly"/>
      <!-- Uses the specified source for the user control -->
      <add tagprefix="MyTags3" tagname="MyCtrl" src="MyControl.ascx"/>
    </controls>
   </pages>
</system.web>

The following code example shows how to use the TagPrefixCollection class to programmatically modify tag-prefix settings. This code example is part of a larger example provided for the PagesSection class.

// Get all current Controls in the collection. 
for (int i = 0; i < pagesSection.Controls.Count; i++)
{
  Console.WriteLine("Control {0}:", i);
  Console.WriteLine("  TagPrefix = '{0}' ",
      pagesSection.Controls[i].TagPrefix);
  Console.WriteLine("  TagName = '{0}' ",
      pagesSection.Controls[i].TagName);
  Console.WriteLine("  Source = '{0}' ",
      pagesSection.Controls[i].Source);
  Console.WriteLine("  Namespace = '{0}' ",
      pagesSection.Controls[i].Namespace);
  Console.WriteLine("  Assembly = '{0}' ",
      pagesSection.Controls[i].Assembly);
}

// Create a new TagPrefixInfo object.
System.Web.Configuration.TagPrefixInfo tagPrefixInfo =
    new System.Web.Configuration.TagPrefixInfo("MyCtrl", "MyNameSpace", "MyAssembly", "MyControl", "MyControl.ascx");

// Execute the Add Method.
pagesSection.Controls.Add(tagPrefixInfo);

// Add a TagPrefixInfo object using a constructor.
pagesSection.Controls.Add(
    new System.Web.Configuration.TagPrefixInfo(
    "MyCtrl", "MyNameSpace", "MyAssembly", "MyControl",
    "MyControl.ascx"));

.NET Framework

Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference

Other Resources