Marshal.GetHRForLastWin32Error Method

Definition

Namespace:

System.Runtime.InteropServices

Assembly:

System.Runtime.InteropServices.dll

Source:

Marshal.cs

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

public:
 static int GetHRForLastWin32Error();

public static int GetHRForLastWin32Error ();

static member GetHRForLastWin32Error : unit -> int

Public Shared Function GetHRForLastWin32Error () As Integer

Returns

Int32

The HRESULT corresponding to the last Win32 error code.

Examples

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)
    {
        Run();
    }
}
// This code example displays the following to the console:
//
// Calling Win32 MessageBox with error...
// The last Win32 Error was: -2147023496

Imports System.Runtime.InteropServices

Module 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)> _
    Function MessageBox(ByVal hwnd As IntPtr, ByVal text As String, ByVal caption As String, ByVal type As UInt32) As Integer
    End Function

End Module

Module Program


    Sub 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.
        Dim HRESULT As Integer

        HRESULT = Marshal.GetHRForLastWin32Error()

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

    End Sub

    Sub Main(ByVal args() As String)

        Run()

    End Sub

End Module

' This code example displays the following to the console: 
'
' Calling Win32 MessageBox with error...
' The last Win32 Error was: -2147023496

Remarks

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.

See also

• DllImportAttribute