隐藏显示窗口
Posted VB.Net
tags:
篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了隐藏显示窗口相关的知识，希望对你有一定的参考价值。
版权声明：本文为博主原创文章，转载请在显著位置标明本文出处以及作者网名，未经作者允许不得用于商业目的。
使用系统的API函数ShowWindow可以隐藏和显示其它程序的窗口。
vb.net中的声明如下：
Declare Function ShowWindow Lib "user32" Alias "ShowWindow" (ByVal hwnd As IntPtr, ByVal nCmdShow As Integer) As Integer
参数hwnd是窗口的句柄；
参数nCmdShow是指定窗口如何显示，用来隐藏和显示的常数：
SW_HIDE= 0
SW_SHOW= 5
隐藏窗口代码：
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim result As Integer
For Each pro As Process In Process.GetProcesses
Try
If pro.ProcessName = "notepad" Then
Dim mainWin As IntPtr = pro.MainWindowHandle
result = ShowWindow(mainWin, SW_HIDE)
End If
Catch ex As Exception
End Try
Next
End Sub显示窗口代码：
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Dim result As Integer
For Each pro As Process In Process.GetProcesses
Try
If pro.ProcessName = "notepad" Then
Dim mainWin As IntPtr = pro.MainWindowHandle
result = ShowWindow(mainWin, SW_SHOW)
End If
Catch ex As Exception
End Try
Next
End Sub如果用了以上代码，会发现，隐藏窗口没问题，但是却不能显示窗口。
添加监视，可以发现显示窗口代码中，mainWin为0，这是因为窗口隐藏后不会有窗口句柄。
只需要在隐藏时把窗口的句柄保存下来就可以隐藏后又显示出来。
修改后的代码如下：
Declare Function ShowWindow Lib "user32" Alias "ShowWindow" (ByVal hwnd As IntPtr, ByVal nCmdShow As Integer) As Integer
Public Const SW_HIDE As Integer = 0
Public Const SW_SHOW As Integer = 5
Dim hwnd As IntPtr = IntPtr.Zero
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim result As Integer
For Each pro As Process In Process.GetProcesses
Try
If pro.ProcessName = "notepad" Then
hwnd = pro.MainWindowHandle
result = ShowWindow(hwnd, SW_HIDE)
Exit For
End If
Catch ex As Exception
End Try
Next
End Sub
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
Dim result As Integer
Try
result = ShowWindow(hwnd, SW_SHOW)
Catch ex As Exception
End Try
End Sub在网上找到的很多代码，只会告诉使用ShowWindow可以隐藏显示窗口，但是并没有告诉需要保存原窗口的句柄。
由于.net平台下C#和vb.NET很相似，本文也可以为C#爱好者提供参考。
学习更多vb.net知识，请参看 vb.net 教程 目录
以上是关于隐藏显示窗口的主要内容，如果未能解决你的问题，请参考以下文章