面板与Pictureboxes闪烁

Question

我需要一种方法来避免在面板上闪烁,我在这里提出了很多类似的问题,并且全世界试图向专家询问,我尝试过很多技巧,扩展面板,创建框架,控制方式,丢失了很多时候,浪费时间学习那些不起作用的东西......我被困在这一点上.

......没有什么能像预期的那样真正起作用,我找到的最好的"Flicker-Reducer"是"Createparams"覆盖子,但是这种方法使任何Form/App x20倍于Form的任何操作,我不想要松散闪烁,如果这意味着应用程序性能松散(至少不是如果CreateParams的性能负相同).

在这个视频中你可以看到我的测试表格有一个50%透明面板,里面有图片框,背景图像设置为"缩放"分层,当我向上或向下滚动时,我得到了很多闪烁.

http://www.youtube.com/watch?v=zIBDTMjrDd4&feature=youtu.be

我使用"CreateParams"方法,如果我不使用"CreateParams",你真的不会看到我的面板闪烁会发生什么,真的很吓人.

这是没有闪烁时的面板:

这是面板在它闪烁的时刻:

这是完整的课程:

It is a Windows Form proyect
VS2012
Framework 3.5
On Windows 7 x64
Application Visual Styles is ON
Double Buffer is ON
Panel and pictureboxes are default controls

(我认为没必要说我已经尝试了所有可能的视觉和环境配置,人们说我永远忘记了闪烁.)

Public Class Form1

    Dim Scroll_Position As Int32 = 0
    Dim Button_Down_Is_Pressed As Boolean = False
    Dim Button_Up_Is_Pressed As Boolean = False
    Dim WithEvents Progressive_Scroll_Timer As New Timer
    Dim SmallChange As Int32 = 5
    Dim Largechange As Int32 = 10

    ' Sub which reduces the Flickering, but this sub makes x20 times slower any operation of any Form/Application.
    Protected Overrides ReadOnly Property CreateParams() As CreateParams
        Get
            Dim cp As CreateParams = MyBase.CreateParams
            cp.ExStyle = cp.ExStyle Or &H2000000
            Return cp
        End Get
    End Property 'CreateParams

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' Me.BackColor = Color.FromArgb(255, 0, 0, 0)
        ' Me.TransparencyKey = Color.FromArgb(255, 0, 0, 0)
        Panel1.VerticalScroll.Maximum = 999999999
        Progressive_Scroll_Timer.Interval = 50
        Panel1.BackColor = Color.FromArgb(150, 0, 0, 0)
    End Sub

    Private Sub Panel_MouseHover(sender As Object, e As EventArgs) Handles Panel1.MouseHover
        sender.focus()
    End Sub

    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Progressive_Scroll_Timer.Tick
        If Button_Down_Is_Pressed Then
            Scroll_Down(SmallChange)
        ElseIf Button_Up_Is_Pressed Then
            Scroll_Up(SmallChange)
        Else
            sender.stop()
        End If
    End Sub

    Private Sub Scroll_Up(ByVal Change As Int32)
        Scroll_Position -= Change
        Panel1.SuspendLayout()
        Try : Panel1.VerticalScroll.Value = Scroll_Position : Catch : Scroll_Position += Change : End Try
        Panel1.ResumeLayout()
    End Sub

    Private Sub Scroll_Down(ByVal Change As Int32)
        Scroll_Position += Change
        Try : Panel1.VerticalScroll.Value = Scroll_Position : Catch : Scroll_Position -= Change : End Try
    End Sub

    Private Sub Button_Down_MouseDown(sender As Object, e As MouseEventArgs) Handles Button2.MouseDown
        If e.Button = Windows.Forms.MouseButtons.Left Then
            Button_Down_Is_Pressed = True
            Progressive_Scroll_Timer.Start()
        End If
    End Sub

    Private Sub Button_Up_MouseDown(sender As Object, e As MouseEventArgs) Handles Button1.MouseDown
        If e.Button = Windows.Forms.MouseButtons.Left Then
            Button_Up_Is_Pressed = True
            Progressive_Scroll_Timer.Start()
        End If
    End Sub

    Private Sub Button_Down_MouseUp(sender As Object, e As MouseEventArgs) Handles Button2.MouseUp
        Button_Down_Is_Pressed = False
    End Sub

    Private Sub Button_Up_MouseUp(sender As Object, e As MouseEventArgs) Handles Button1.MouseUp
        Button_Up_Is_Pressed = False
    End Sub

    Private Sub Form_MouseWheel(ByVal sender As Object, ByVal e As MouseEventArgs) Handles Panel1.MouseWheel
        If Panel1.Focused Then
            Select Case Math.Sign(e.Delta)
                Case Is > 0 : Scroll_Up(Largechange)
                Case Is < 0 : Scroll_Down(Largechange)
            End Select
        End If
    End Sub

End Class

Answer 1

设置Panel的AutoScroll属性true.如果没有这个,滚动似乎不起作用.添加从DoubleBufferedPanel类继承的Panel类并将该.DoubleBuffered属性设置为true:

Public Class DoubleBufferedPanel
    Inherits Panel

    Public Sub New()
        DoubleBuffered = True
    End Sub
End Class

现在转到隐藏InitializeComponent子(右键单击Panel1变量并单击Go To Definition).在需要的地方替换Panel类型DoubleBufferedPanel(两个地方):

Me.Panel1 = New WindowsApplication4.DoubleBufferedPanel()
....
Friend WithEvents Panel1 As WindowsApplication4.DoubleBufferedPanel

闪烁应该停止(尽管还有一些其他的影响).删除CreateParams以提高速度.

PS总的来说,这不是一个好主意(移动复杂的半透明图像).你为什么不用这样的东西ListView？为什么不自己移动图像而不使用Panel？如果你想要最好的速度,只需.BackgroundImage使用Bitmap和Graphics类在你的表单()上绘制图像.

PPS似乎与编程滚动一些严重的错误Panel使用.AutoScroll = true.我不得不重新分配滚动值以防止严重的抖动.我已经隔离了这个案例,他将向微软提交一份错误报告.