查找并最小化、最大化或还原窗口

引言

GetWindowPlacement、SetWindowPlacement 和 FindWindow：使用这些 API 函数，我们可以最小化、最大化或还原窗口。

使用这些函数

• GetWindowPlacement

GetWindowPlacement 函数检索指定窗口的显示状态以及还原、最小化和最大化位置。

GetWindowPlacement (ByVal hwnd As Integer, ByRef lpwndpl As WINDOWPLACEMENT) As Integer

• SetWindowPlacement

SetWindowPlacement 函数设置指定窗口的显示状态以及还原、最小化和最大化位置。

SetWindowPlacement (ByVal hwnd As Integer, ByRef lpwndpl As WINDOWPLACEMENT) As Integer

• FindWindow

FindWindow 函数检索一个句柄，指向类名和窗口名称与指定字符串匹配的顶级窗口。此函数不搜索子窗口。此函数不执行区分大小写的搜索。

FindWindow(string lpClassName,string lpWindowName)

用法

Public Class Minimize

    Private Declare Function FindWindow Lib "user32" Alias _
            "FindWindowA" (ByVal lpClassName As String, _
            ByVal lpWindowName As String) As Integer
    Private Declare Function GetWindowPlacement Lib _
            "user32" (ByVal hwnd As Integer, _
            ByRef lpwndpl As WINDOWPLACEMENT) As Integer
    Private Declare Function SetWindowPlacement Lib "user32" _
           (ByVal hwnd As Integer, ByRef lpwndpl As WINDOWPLACEMENT) As Integer
    Private Const SW_SHOWMINIMIZED As Short = 2
    Private Const SW_SHOWMAXIMIZED As Short = 3
    Private Const SW_SHOWNORMAL As Short = 1

    Private Structure POINTAPI
        Dim X As Integer
        Dim Y As Integer
    End Structure

    Private Structure RECT
        Dim Left_Renamed As Integer
        Dim Top_Renamed As Integer
        Dim Right_Renamed As Integer
        Dim Bottom_Renamed As Integer
    End Structure

    Private Structure WINDOWPLACEMENT
        Dim length As Integer
        Dim flags As Integer
        Dim showCmd As Integer
        Dim ptMinPosition As POINTAPI
        Dim ptMaxPosition As POINTAPI
        Dim rcNormalPosition As RECT
    End Structure

   
    Public Sub windowAction(ByVal classname As String, ByVal action As String)

        Dim app_hwnd As Integer
        Dim wp As WINDOWPLACEMENT
        app_hwnd = FindWindow(classname, vbNullString)
        wp.length = Len(wp)
        GetWindowPlacement(app_hwnd, wp)

        Select Case action

            Case "Minimize"
                 wp.showCmd = SW_SHOWMINIMIZED
            Case "Maximize"

                 wp.showCmd = SW_SHOWMAXIMIZED

            Case "Restore"
                wp.showCmd = SW_SHOWNORMAL
        End Select
        SetWindowPlacement(app_hwnd, wp)

    End Sub
End Class
'Use this Class
'This is sample for Minimize the notepad window

Private Sub Button1_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles Button1.Click
    Dim test As New Minimize
    test.windowAction("Notepad", "Minimize")
End Sub