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HRESULT_FROM_WIN32 macro

Applies to: desktop apps only

Maps a system error code to an HRESULT value.

Syntax

Copy 
HRESULT HRESULT_FROM_WIN32(
  DWORD x
);

Parameters

x

The system error code.

Return value

The HRESULT value.

Remarks

This macro is defined as follows:

Copy 
//
// HRESULT_FROM_WIN32(x) used to be a macro, however we now run it as an inline function
// to prevent double evaluation of 'x'. If you still need the macro, you can use __HRESULT_FROM_WIN32(x)
//
#define __HRESULT_FROM_WIN32(x) ((HRESULT)(x) <= 0 ? ((HRESULT)(x)) : ((HRESULT) (((x) & 0x0000FFFF) | (FACILITY_WIN32 << 16) | 0x80000000)))

#ifndef __midl
FORCEINLINE HRESULT HRESULT_FROM_WIN32(unsigned long x) { 
   return (HRESULT)(x) <= 0 ? (HRESULT)(x) : (HRESULT) (((x) & 0x0000FFFF) | (FACILITY_WIN32 << 16) | 0x80000000);
}
#else
#define HRESULT_FROM_WIN32(x) __HRESULT_FROM_WIN32(x)
#endif

Requirements

Minimum supported client

Windows 2000 Professional

Minimum supported server

Windows 2000 Server

Header
Winerror.h

See also

Error Handling

 

 

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Build date: 3/7/2012

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Better C# alternative
Even better is to simply use this method: int hResult = Marshal.GetHRForLastWin32Error()
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A C# conversion 
static Int32 HRESULT_FROM_WIN32(Int32 win32Error)
{
 const Int32 FACILITY_WIN32 = 7;
 UInt32 hr = win32Error <= 0
  ? (UInt32)(win32Error)
  : (((UInt32)(win32Error & 0x0000FFFF) | (FACILITY_WIN32 << 16) | 0x80000000));
 return (Int32)hr;
}
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