Question

如何使用VB.NET代码关闭显示器？好的，实际上我找到了C＃解决方案。但我需要VB.NET解决方案。我尝试过在线C＃到VB.NET转换器，但转换器抱怨它有错误。

如何将以下C＃代码转换为VB.NET？

using System.Runtime.InteropServices; //to DllImport

public int WM_SYSCOMMAND = 0x0112;
public int SC_MONITORPOWER = 0xF170; //Using the system pre-defined MSDN constants that can be used by the SendMessage() function .

[DllImport("user32.dll")]
private static extern int SendMessage(int hWnd, int hMsg, int wParam, int lParam);
//To call a DLL function from C#, you must provide this declaration.

private void button1_Click(object sender, System.EventArgs e)
{
    SendMessage( this.Handle.ToInt32() , WM_SYSCOMMAND , SC_MONITORPOWER ,2 );//DLL function
}

更新

我使用online developer Fusion converter。

Answer 1

试试这个

Public WM_SYSCOMMAND As Integer = &H112
Public SC_MONITORPOWER As Integer = &Hf170

<DllImport("user32.dll")> _
Private Shared Function SendMessage(hWnd As Integer, hMsg As Integer, wParam As Integer, lParam As Integer) As Integer
End Function

Private Sub button1_Click(sender As Object, e As System.EventArgs)
    SendMessage(Me.Handle.ToInt32(), WM_SYSCOMMAND, SC_MONITORPOWER, 2)
End Sub

Answer 2

是的，接受的答案中的声明不正确。由于传递的参数大小错误，因此在64位版本的Windows上可能会出现随机故障。他们应该是这样的：

Private Const WM_SYSCOMMAND As Integer = &H112
Private Const SC_MONITORPOWER As Integer = &HF170
Private Const MonitorToLowPower As Integer = 1
Private Const MonitorShutoff As Integer = 2

<DllImport("user32.dll")> _
Private Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal hMsg As Integer, _
                          ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
End Function

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    SendMessage(Me.Handle, WM_SYSCOMMAND, 
                CType(SC_MONITORPOWER, IntPtr), CType(MonitorShutoff, IntPtr))
End Sub

您可以添加对SendMessage（）的返回值的检查，它应该返回IntPtr.Zero。不太确定它是否有用，对于用户而言，由于某种原因该命令不起作用将是非常明显的。

Answer 3

这个适用于使用VB 2008的Windows 7。并且不用担心再次打开显示器，因为这就像电源选项中的“关闭显示器”一样。显示器关闭并重新打开，您必须按键盘上的任意键或移动鼠标。

Imports System.Runtime.InteropServices

Public Class Monitoroff

Public WM_SYSCOMMAND As Integer = &H112

Public SC_MONITORPOWER As Integer = &HF170

<DllImport("user32.dll", SetLastError:=True)> _
Private Shared Function SendMessage(ByVal hWnd As Integer, ByVal hMsg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer
End Function

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    SendMessage(Me.Handle.ToInt32(), WM_SYSCOMMAND, SC_MONITORPOWER, 2)
End Sub
End Class

如何使用VB.NET代码关闭监视器

3 个答案: