Searches for the specified object and returns the index of the first occurrence within the entire list.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
Return ValueType: System.Int32
The zero-based index of the first occurrence of the value parameter; otherwise, -1 if value is not in the list.
Although the implementation is dependent on the underlying list's IndexOf method, typically the following characteristics apply:
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.