Marshal.StringToCoTaskMemUni(String) Method

Definition

Namespace:

System.Runtime.InteropServices

Assemblies:

netstandard.dll, System.Runtime.InteropServices.dll

Source:

Marshal.cs

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

C#

public static IntPtr StringToCoTaskMemUni(string? s);

Parameters

s

String

A managed string to be copied.

Returns

IntPtr

An integer representing a pointer to the block of memory allocated for the string, or 0 if s is null.

Exceptions

ArgumentOutOfRangeException

The s parameter exceeds the maximum length allowed by the operating system.

OutOfMemoryException

There is insufficient memory available.

Remarks

StringToCoTaskMemUni is useful for custom marshaling or for use when mixing managed and unmanaged code. Because 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.

This API reflects the Windows definition of Unicode, which is a UTF-16 2-byte encoding. On many non-Windows platforms, the wchar_t data-type is 4-bytes, not 2-bytes. Consult your compiler to confirm if wchar_t can be used or char16_t should be used instead.

Applies to

See also

• FreeCoTaskMem(IntPtr)
• PtrToStringUni(IntPtr, Int32)