Marshal.GetHRForLastWin32Error Method ()


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Returns the HRESULT corresponding to the last error incurred by Win32 code executed using Marshal.

Namespace:   System.Runtime.InteropServices
Assembly:  mscorlib (in mscorlib.dll)

public static int GetHRForLastWin32Error()

Return Value

Type: System.Int32

The HRESULT corresponding to the last Win32 error code.

The target function must have had the setLastError metadata flag set. For example, the SetLastError field of the System.Runtime.InteropServices.DllImportAttribute must be true. The process for setting this flag depends on the source language used: C# and C++ are false by default, but the Declare statement in Visual Basic is true.

The following example demonstrates how to retrieve an HRESULT corresponding to a Win32 error code using the GetHRForLastWin32Error method.

using System;
using System.Runtime.InteropServices;

internal class Win32
    // Use DllImportAttribute to inport the Win32 MessageBox
    // function.  Set the SetLastError flag to true to allow
    // the function to set the Win32 error.
    [DllImportAttribute("user32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
    public static extern int MessageBox(IntPtr hwnd, String text, String caption, uint type);


class Program

    static void Run()

        // Call the MessageBox with an invalid window handle to
        // produce a Win32 error.

        Console.WriteLine("Calling Win32 MessageBox with error...");

        Win32.MessageBox(new IntPtr(123132), "Press OK...", "Press OK Dialog", 0);

        // Get the last error and display it.

        int HRESULT = Marshal.GetHRForLastWin32Error();

        Console.WriteLine("The last Win32 Error was: " + HRESULT);

    static void Main(string[] args)
// This code example displays the following to the console: 
// Calling Win32 MessageBox with error...
// The last Win32 Error was: -2147023496


requires full trust for the immediate caller. This member cannot be used by partially trusted or transparent code.

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
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