ClientScriptManager::IsStartupScriptRegistered Method (Type, String)
Determines whether the startup script is registered with the Page object using the specified key and type.
Assembly: System.Web (in System.Web.dll)
Parameters
- type
- Type: System::Type
The type of the startup script to search for.
- key
- Type: System::String
The key of the startup script to search for.
| Exception | Condition |
|---|---|
| ArgumentNullException | The startup script type is nullptr. |
Call this method before calling the RegisterStartupScript method to avoid registering duplicate scripts. This is particularly important if the script requires a large amount of server resources to create.
A client startup script is uniquely identified by its key and its type. Scripts with the same key and type are considered duplicates.
The following code example demonstrates the use of the IsStartupScriptRegistered method. Note that, if the logic to check for the existing startup script block were removed, there would not be two duplicate startup scripts in the HTML source code of the rendered page because the RegisterStartupScript method checks for duplicates. The benefit of checking is to reduce unnecessary computation.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.