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Marshal.StringToCoTaskMemUni Method

Copies the contents of a managed String to a block of memory allocated from the unmanaged COM task allocator.

[Visual Basic]
Public Shared Function StringToCoTaskMemUni( _
   ByVal s As String _
) As IntPtr
public static IntPtr StringToCoTaskMemUni(
 string s
public: static IntPtr StringToCoTaskMemUni(
 String* s
public static function StringToCoTaskMemUni(
   s : String
) : IntPtr;


A managed string to be copied.

Return Value

An integer representing a pointer to the block of memory allocated for the string, or 0 if a null reference (Nothing in Visual Basic) string was supplied.


Exception Type Condition
OutOfMemoryException There is insufficient memory available.


StringToCoTaskMemUni is useful for custom marshaling or for use when mixing managed and unmanaged code. Since this method allocates the unmanaged memory required for a string, always free the memory by calling Marshal.FreeCoTaskMem. This method provides the opposite functionality of Marshal.PtrToStringUni. The characters of the string are copied as Unicode characters.

Note   This method uses SecurityAction.LinkDemand to prevent it from being called from untrusted code; only the immediate caller is required to have SecurityPermissionAttribute.UnmanagedCode permission. If your code can be called from partially trusted code, do not pass user input to Marshal class methods without validation. For important limitations on using the LinkDemand member, see Demand vs. LinkDemand.


Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

.NET Framework Security: 

See Also

Marshal Class | Marshal Members | System.Runtime.InteropServices Namespace | FreeCoTaskMem | PtrToStringUni