Imports System Drawing Imports System Windows Forms ****************************************** Private oOriginalRegion As Region = Nothing 用于窗体移动 Private bFormDragging As Boolean = False Private oPointClicked As Point ****************************************** Private Sub Form _MouseDown(ByVal sender As Object ByVal e As System Windows Forms MouseEventArgs) Handles MyBase MouseDown Me bFormDragging = True Me oPointClicked = New Point(e X e Y) End Sub ****************************************** Private Sub Form _MouseUp(ByVal sender As Object ByVal e As System Windows Forms MouseEventArgs) Handles MyBase MouseUp Me bFormDragging = False End Sub ****************************************** Private Sub Form _MouseMove(ByVal sender As Object ByVal e As System Windows Forms MouseEventArgs) Handles MyBase MouseMove If Me bFormDragging Then Dim oMoveToPoint As Point 以当前鼠标位置为基础 找出目标位置 oMoveToPoint = Me PointToScreen(New Point(e X e Y)) 根据开始位置作出调整 oMoveToPoint Offset(Me oPointClicked X * _ (Me oPointClicked Y + _ SystemInformation CaptionHeight + _ SystemInformation BorderSize Height) * ) 移动窗体 Me Location = oMoveToPoint End If
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lishixinzhi/Article/program/ASP/201311/21755
直接添加一个MID父窗体或在已有窗体的属性中找到IsMDIContainer属性，然后设置为True，然后创建第二个窗体 ，需要加载子窗体的时候：
Dim NewMDIChild As New Form2
NewMDIChild.MdiParent = Me
NewMDIChild.Show()
Public Shared Sub CheckMDIChildForm(ByVal MDIForm As Windows.Forms.Form, ByVal MDIChildForm As Windows.Forms.Form, ByVal MDIChildFormName As String)
If MDIForm.MdiChildren.Length 1 Then
'如果没有任何一个MDI子窗体，则创该MDI子窗体的窗体实例
Dim MDIChildFrm As Windows.Forms.Form = MDIChildForm ' 定义MDI子窗体
MDIChildFrm.MdiParent = MDIForm '指定父窗体
MDIChildFrm.Show() '打开窗体
Exit Sub
Else
Dim x As Integer
Dim frmyn As Boolean
For x = 0 To (MDIForm.MdiChildren.Length) - 1
Dim tempChild As Windows.Forms.Form = CType(MDIForm.MdiChildren(x), Windows.Forms.Form)
If tempChild.Name = MDIChildFormName Then
'检测到有该MDI子窗体，设为激活 并退出循环
frmyn = True
tempChild.BringToFront()
Exit For
Else
frmyn = False
End If
Next
If Not frmyn Then
'在打开的窗体中没检测到则新建
Dim MDIChildFrm As Windows.Forms.Form = MDIChildForm ' 定义MDI子窗体
MDIChildFrm.MdiParent = MDIForm '指定父窗体
MDIChildFrm.Show() '打开窗体
End If
End If
End Sub
If App.PrevInstance = True Then
End
End If
如果程序正在运行，结束程序。
在模块中加入每个窗口的标题变量。
然后用if then 来判断是否有相同窗口。
如果你事先不知道有哪些窗口的话，那你就用枚举 FindWindow来查找子窗口句柄。再用SendMessage 获得窗口标题再进行判断。
Imports System.Text
Imports System.Runtime.InteropServices
Public Class Form1
' 相关API函数声明,注释掉的这里没用到，但是也比较常用吧，这些函数的功能都能搜到。
Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr
Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" (ByVal hWnd1 As IntPtr, ByVal hWnd2 As IntPtr, ByVal lpsz1 As String, ByVal lpsz2 As String) As IntPtr
Private Delegate Function EnumChildProc(ByVal hWnd As IntPtr, ByVal lParam As Integer) As Boolean
Private Declare Function EnumChildWindows Lib "user32.dll" (ByVal hWndParent As IntPtr, ByVal lpEnumFunc As EnumChildProc, ByVal lParam As Integer) As Boolean
Private Declare Auto Function SendMessage Lib "User32.dll" (ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As Integer, ByVal lParam As String) As Integer
'Private Declare Function CheckDlgButton Lib "user32" Alias "CheckDLGButtonA" (ByVal hDlg As IntPtr, ByVal nIDButton As IntPtr, ByVal wCheck As Integer) As Integer
Private Declare Function GetClassName Lib "user32" Alias "GetClassNameA" (ByVal hWnd As IntPtr, ByVal lpClassName As StringBuilder, ByVal nMaxCount As Integer) As Integer
'Private Declare Function GetWindowThreadProcessId Lib "user32" Alias "GetWindowThreadProcessId" (ByVal hwnd As IntPtr, ByVal lpdwProcessId As Long) As Integer
Private Declare Auto Function GetWindowTextLength Lib "user32" Alias "GetWindowTextLength" (ByVal hwnd As IntPtr) As Integer
Private Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" (ByVal hwnd As IntPtr, ByVal lpString As StringBuilder, ByVal cch As Integer) As Integer
' 相关消息定义，也有没用到的
Const WM_SETTEXT = HC
Const WM_GETTEXT = HD
'Const WM_SETFOCUS = H7
'Const WM_KILLFOCUS = H8
'Const WM_CLOSE = H10
'Const WM_SYSCOMMAND = H112
'Const SC_CLOSE = HF060
'Const SC_MINIMIZE = HF020
Const BM_GETCHECK = HF0
Const BM_SETCHECK = HF1
Const BM_GETSTATE = HF2
Const BM_SETSTATE = HF3
Const BM_SETSTYLE = HF4
Const BM_CLICK = HF5
'Const BM_GETIMAGE = HF6
'Const BM_SETIMAGE = HF7
Const BST_UNCHECKED = O0
Const BST_CHECKED = O1
Const BST_INDETERMINATE = O2
' 储存窗口句柄
Dim WindowHandle As IntPtr
' 储存两个（或者多个）编辑框句柄
Dim EditHandle As New List(Of IntPtr)
Dim EditWindowsText As List(Of String)
' 储存复选框句柄
Dim CheckHandle As IntPtr = 0
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Button1_Click(sender, e)
End Sub
' EnumChildWindows 回调函数，该函数名作为API函数EnumChildWindows 的一个参数
' 该函数实现了枚举各个子窗口，找出编辑框属性的功能
Public Function EnumChildProcC(ByVal hwnd As IntPtr, ByVal lParam As Integer) As Boolean
Dim dwWindowClass As StringBuilder = New StringBuilder(100)
' 获得某一个句柄的类名
GetClassName(hwnd, dwWindowClass, 100)
If dwWindowClass.ToString.Contains("EDIT") Or dwWindowClass.ToString.Contains("Edit") Then ' 类名包含EDIT的为编辑框
EditHandle.Add(hwnd) ' 存储该句柄
End If
' 返回 True 一直枚举完
Return True
End Function
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
WindowHandle = FindWindow(vbNullString, "登陆")
If WindowHandle.ToInt32 = 0 Then
MsgBox("未捕获到窗口" + "登陆")
Return
End If
' 枚举所有主窗口的子窗口（控件），枚举时自动调用回调函数，完成编辑框句柄的获取
EnumChildWindows(WindowHandle, AddressOf EnumChildProcC, 0)
' 寻找复选框
CheckHandle = FindWindowEx(WindowHandle, IntPtr.Zero, vbNullString, "记住密码")
Dim str As New StringBuilder
Dim j As Integer = 0
' 对编辑框文本赋值
For j = 0 To EditHandle.Count - 1
SendMessage(EditHandle(j), WM_SETTEXT, 0, "Text")
'GetWindowText(EditHandle(j), str, 20)
'EditWindowsText.Add(Str.ToString)
'Str.Clear()
Next
If EditHandle.Count = 0 Then
MsgBox("未找到输入框！")
End If
If CheckHandle.ToInt32 0 Then
'CheckDlgButton(WindowHandle, id, 1)
' 对复选框进行鼠标单击操作
SendMessage(CheckHandle, BM_CLICK, 0, 0)
'SendMessage(CheckHandle, BM_SETCHECK, True, 0)
End If
End Sub
End Class