面板閃爍與Pictureboxes

Question

我需要一種方法來避免閃爍在面板上，我在這裏做了很多類似的問題和世界上所有的試圖詢問專家身邊，我已經嘗試了很多花樣，擴展板，的CreateParams，的ControlStyles，失去了很多的時間，浪費時間學習的東西會不工作......我被困在這一點上幾個月。

...沒有什麼能像預期的那樣真正起作用，我發現的最好的「Flicker-Reducer」是「Createparams」重寫子，但是這種方法使Form/App x20的任何操作都變得更慢，我不想失去閃爍如果這意味着寬鬆的應用性能太（至少不是如果是的CreateParams相同的性能不利點）。

在這個視頻中，你可以看到我的測試表單有一個50％的透明面板，裏面有圖片框，背景圖像設置爲「縮放」分層，當我向上或向下滾動時，我得到很多閃爍。

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

我用「的CreateParams」的方法，真的是你不會看到我的面板的閃爍會發生什麼，如果我不使用「的CreateParams」，真正可怕的。

這是當不閃爍面板：

而且這是在某一時刻的面板，它閃爍：

下面是完整的類：

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 

（我覺得沒有必要說我已經嘗試了所有可能的視覺和環境配置，人們說我永遠忘不了閃爍。）

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

將Panel的AutoScroll屬性設置爲true。沒有這個滾動似乎沒有工作。 添加DoubleBufferedPanel類從Panel類繼承並設置.DoubleBuffered屬性設置爲true：

Public Class DoubleBufferedPanel 
    Inherits Panel 

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

現在去隱藏InitializeComponent子（在Panel1可變單擊鼠標右鍵，然後單擊Go To Definition）。與DoubleBufferedPanel更換Panel類型需要的地方（兩處）：

的閃爍應該停止（雖然還存在一些其他的效果）。 取出CreateParams來提高速度。

P.S.總體而言，這不是一個好主意（移動複雜的半透明圖像）。你爲什麼不使用類似ListView的東西？你爲什麼不自己移動的圖像，而不使用Panel？如果您想獲得最佳速度，請使用Bitmap和Graphics類在表單上繪製圖像（.BackgroundImage）。

P.P.S.編程式滾動Panel與.AutoScroll = true似乎有一些嚴重的錯誤。我不得不重新分配滾動值以防止嚴重抖動。我已經隔離了這個情況，並會向微軟提交錯誤報告。

Answer 2

使用複合class表示panel和它的內容，然後油漆（01​​）即到Picturebox將很好地渲染。我做過幾個這樣的項目。

Answer 3

你可能形式的DoubleBuffered屬性設置爲True

編輯：

我覺得你不需要定時器。 因此，修改後的代碼將是有點像這樣：

Public Class Form1 

    Dim Scroll_Position As Int32 = 0 
    Dim SmallChange As Int32 = 5 
    Dim Largechange As Int32 = 10 

    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 
     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 Scroll_Up(ByVal Change As Int32) 
     Try 
      Scroll_Position -= Change 
      Panel1.VerticalScroll.Value = Scroll_Position 
     End Try 
    End Sub 

    Private Sub Scroll_Down(ByVal Change As Int32) 
     Try 
      Scroll_Position += Change 
      Panel1.VerticalScroll.Value = Scroll_Position 
     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 
      scrollDown(smallChange) 
     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 
      scrollUp(SmallChange) 
     End If 
    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 

這可能不是解決辦法，但是這是從我身旁的努力。

Answer 4

把這個在您的形式負載

' to remove flick 
Dim aProp As PropertyInfo = GetType(Panel).GetProperty("DoubleBuffered", BindingFlags.NonPublic Or BindingFlags.Instance) 
     aProp.SetValue(Panel7, True, Nothing) 

與背景圖像控件的名稱替換Panel7。