我编写了以下过程来移动和停靠无边框窗口：
Public Class frmNavigation
Inherits Form
'Declarations to allow form movement on mouse down
Private IsFormBeingDragged As Boolean = False
Private MouseDownX As Integer
Private MouseDownY As Integer
Dim Xs As Integer
Dim Ys As Integer
Dim DockScale As Integer
Private Sub frmNavigation_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs) Handles MyBase.MouseDown
'This procedure allows the user to move the form when the
'mouse button is down. The form does not have borders, so it
'needs to be coded to move.
If e.Button = MouseButtons.Left Then
IsFormBeingDragged = True
MouseDownX = e.X
MouseDownY = e.Y
End If
End Sub
Private Sub frmNavigation_MouseUp(ByVal sender As Object, ByVal e As MouseEventArgs) Handles MyBase.MouseUp
'This procedure allows the user to move the form when the
'mouse button is up. The form does not have borders, so it
'needs to be coded to move.
If e.Button = MouseButtons.Left Then
IsFormBeingDragged = False
End If
End Sub
Private Sub frmNavigation_MouseMove(ByVal sender As Object, ByVal e As MouseEventArgs) Handles MyBase.MouseMove
'This procedure allows the user to move the form when the
'mouse button is dragging the form. The form does not have borders, so it
'needs to be coded to move.
Dim curScreen As Screen
curScreen = Screen.PrimaryScreen 'curScreen = Screen.AllScreens(0)
Dim height As Integer = curScreen.Bounds.Height
Dim width As Integer = curScreen.Bounds.Width
width = curScreen.WorkingArea.Width
height = curScreen.WorkingArea.Height
If IsFormBeingDragged Then
Dim temp As System.Drawing.Point = New System.Drawing.Point()
Xs = MouseDownX
Ys = MouseDownY
temp.X = Me.Location.X + (e.X - MouseDownX)
temp.Y = Me.Location.Y + (e.Y - MouseDownY)
Me.Location = temp
temp = Nothing
End If
End Sub
End Class
到目前为止，这按设计工作，它移动表单没有任何问题。当我添加代码以将表单停靠在鼠标移动事件下时，问题就开始了：
Private Sub frmNavigation_MouseMove(ByVal sender As Object, ByVal e As MouseEventArgs) Handles MyBase.MouseMove
'This procedure allows the user to move the form when the
'mouse button is dragging the form. The form does not have borders, so it
'needs to be coded to move.
Dim curScreen As Screen
curScreen = Screen.PrimaryScreen 'curScreen = Screen.AllScreens(0)
Dim height As Integer = curScreen.Bounds.Height
Dim width As Integer = curScreen.Bounds.Width
width = curScreen.WorkingArea.Width
height = curScreen.WorkingArea.Height
If IsFormBeingDragged Then
Dim temp As System.Drawing.Point = New System.Drawing.Point()
Xs = MouseDownX
Ys = MouseDownY
temp.X = Me.Location.X + (e.X - MouseDownX)
temp.Y = Me.Location.Y + (e.Y - MouseDownY)
Me.Location = temp
temp = Nothing
End If
If IsFormBeingDragged = True And e.Button = MouseButtons.Left Then
'if the drag flag is true and left mouse button is pressed...
'set Top side docking
If Me.Top + (MouseDownY - Ys) < DockScale Then
Me.Top = 0
Exit Sub
End If
'set bottom side docking
If Me.Top + (MouseDownY - Ys) + Me.Height > (height - DockScale) Then
Me.Top = height - Me.Height
Exit Sub
End If
'move the form finally
Me.Left = Me.Left + (MouseDownX - Xs)
Me.Top = Me.Top + (e.Y - Ys)
End If
End Sub
当我添加用于停靠的代码并尝试移动表单时，它会移动并停靠，但是当按住鼠标并移动时它会疯狂地闪烁。我不明白为什么会发生这种情况，这是我第一次涉足这样的事情，所以我不确定我哪里出错了。