如下代码示例如何在C#中取得Win32的GetLastError.

// this function is just for fun

[DllImport("winusb.dll", SetLastError = true

)]

public static extern bool WinUsb_SetPowerPolicy(IntPtr InterfaceHandle, UInt32 PolicyType, UInt32 ValueLength, ref Byte Value);

// this function is just for fun

[DllImport("winusb.dll", SetLastError = true

)]

public static extern bool WinUsb_Initialize(Microsoft.Win32.SafeHandles.SafeFileHandle DeviceHandle, ref IntPtr InterfaceHandle);

public bool SetPowerPolicy()

{

// this function never work

IntPtr interfaceHandle = IntPtr.Zero;

Microsoft.Win32.SafeHandles.SafeFileHandle sfh = new Microsoft.Win32.SafeHandles.SafeFileHandle(new IntPtr(this.deviceHandle), true);

bool temp = USBXpressAPI.WinUsb_Initialize(sfh, ref interfaceHandle);

System.ComponentModel.Win32Exception we = new System.ComponentModel.Win32Exception(System.Runtime.InteropServices.Marshal.GetLastWin32Error());

System.Console.WriteLine(we.Message);

byte value = 1;

bool result = USBXpressAPI.WinUsb_SetPowerPolicy(interfaceHandle, (uint)0x01, (uint)1, ref value);

return result;

}