Marshal.StringToHGlobalUni(String) Method

Reference

Definition

Namespace:: System.Runtime.InteropServices

Assembly:: System.Runtime.InteropServices.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Source:: Marshal.cs

Source:: Marshal.cs

Source:: Marshal.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Copies the contents of a managed String into unmanaged memory.

public:
 static IntPtr StringToHGlobalUni(System::String ^ s);

[System.Security.SecurityCritical]
public static IntPtr StringToHGlobalUni (string s);

public static IntPtr StringToHGlobalUni (string? s);

public static IntPtr StringToHGlobalUni (string s);

[<System.Security.SecurityCritical>]
static member StringToHGlobalUni : string -> nativeint

static member StringToHGlobalUni : string -> nativeint

Public Shared Function StringToHGlobalUni (s As String) As IntPtr

Parameters

s: String

A managed string to be copied.

Returns

IntPtr

nativeint

The address, in unmanaged memory, to where the s was copied, or 0 if s is null.

Attributes: SecurityCriticalAttribute

Exceptions

OutOfMemoryException

The method could not allocate enough native heap memory.

ArgumentOutOfRangeException

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

Remarks

StringToHGlobalUni 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 FreeHGlobal. This method provides the opposite functionality of Marshal.PtrToStringUni.

This method copies embedded null characters, and includes a terminating null character.

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