[转] Tips - C#获取LastError

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;
}