c# - 尽管有双缓冲，行情仍然闪烁

Question

有没有人知道如何消除闪烁？我在 SO 和网络上进行了研究，并尝试了许多不同的方法，例如将 TickerControl 放入双缓冲面板中 Double Buffering when not drawing in OnPaint(): why doesn't it work?等等，还有很多其他的东西。它仍然闪烁，不是在每次重绘时都闪烁，而是每秒闪烁几次。

此外，即使在 OnPaint 中删除了“g.Clear(BackColor)”之后，某些内容仍必须清除背景，因为文本继续以可读方式滚动。

这里是我的 TickerControl 类的相关部分:

class TickerControl : Control
{
    private static readonly StringFormat stringFormat = new StringFormat(StringFormatFlags.NoWrap);

    private const int padding = 40;
    private const int scrollSleep = 10;
    private const int scrollAdvancePixels = 1;

    private float textWidth;
    private float currentX;

    private static readonly Timer scrollTimer = new Timer();

    public TickerControl()
    {
        this.SetStyle(ControlStyles.UserPaint |
                      ControlStyles.AllPaintingInWmPaint |
                      ControlStyles.OptimizedDoubleBuffer
                      , true);
        scrollTimer.Tick += AdvanceText;
        scrollTimer.Interval = scrollSleep;
        scrollTimer.Enabled = true;
    }

    private void AdvanceText(object sender, EventArgs e)
    {
        if (IsDisposed)
            return;

        currentX -= scrollAdvancePixels;
        if (currentX <= -textWidth)
            currentX = 0;
        Invalidate();
    }

    protected override void OnPaintBackground(PaintEventArgs pevent)
    {
    }

    protected override void OnPaint(PaintEventArgs e)
    {
        Graphics g = e.Graphics;

        g.Clear(BackColor);

        using (SolidBrush brush = new SolidBrush(ForeColor))
        {
            g.DrawString(Text, Font, brush, currentX, 0, stringFormat);
            g.DrawString(Text, Font, brush, currentX + textWidth, 0, stringFormat);
        }
    }

有什么想法吗？

更新:

正如 sallushan 建议的手动双缓冲，让我补充一点，我之前已经尝试过，使用下面的代码。但在屏幕上它看起来与上面完全一样，所以问题似乎不在我的 OnPaint 方法中。我想它一定在我的控件设置中的某个地方。

    private Bitmap backBuffer;

    protected override void OnPaint(PaintEventArgs e)
    {
        if (backBuffer == null)
            backBuffer = new Bitmap(this.ClientSize.Width, this.ClientSize.Height);

        Graphics g = Graphics.FromImage(backBuffer);

        g.Clear(BackColor);

        using (SolidBrush brush = new SolidBrush(ForeColor))
        {
            g.DrawString(Text, Font, brush, currentX, 0, stringFormat);
            g.DrawString(Text, Font, brush, currentX + textWidth, 0, stringFormat);
        }

        g.Dispose();

        e.Graphics.DrawImageUnscaled(backBuffer, 0, 0);
    }

    protected override void OnPaintBackground(PaintEventArgs pevent)
    {
        // Don't call base!
    }

    protected override void OnSizeChanged(EventArgs e)
    {
        if (backBuffer != null)
        {
            backBuffer.Dispose();
            backBuffer = null;
        }
        base.OnSizeChanged(e);
    }

Answer 1

在您的表单中设置此代码。它将消除闪烁

 protected override CreateParams CreateParams
        {
            get
            {
                CreateParams cp = base.CreateParams;
                cp.ExStyle |= 0x02000000;

                return cp;
            }
        }

希望对你有帮助