c# - 在面板上移动高质量的线 c#

Question

我想在面板上画一条线，然后随着鼠标的移动而移动。为此，我绘制了一条线，当鼠标移动时，我将线重新绘制到新位置，并通过绘制一 strip 有背景颜色的线来删除上一条线。如果我不使用高质量平滑模式，它工作正常。但是如果使用高质量的平滑模式，它会在面板上留下痕迹。有人知道如何解决这个问题吗？谢谢你。这是代码

        int x_previous = 0;
        int y_previous = 0;

        private void panel1_MouseMove(object sender, MouseEventArgs e)
        {
            Pen pen1 = new System.Drawing.Pen(Color.Black, 3);
            Pen pen2 = new System.Drawing.Pen(panel1.BackColor, 3);
            Graphics g = panel1.CreateGraphics();
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            g.DrawLine(pen2, new Point(0, 0), new Point(x_previous, y_previous));
            g.DrawLine(pen1, new Point(0, 0), new Point(e.Location.X, e.Location.Y));
            x_previous = e.Location.X;
            y_previous = e.Location.Y;
        }

这是使用 SmoothingMode 的快照

这是没有 SmoothingMode 的快照

Answer 1

最安全的选择是使用 g.Clear(panel1.BackColor) 清除图形，而不是在一条线上画一条线。这将清除已绘制的所有内容，以便您可以安全地绘制一条新线:

private void panel1_MouseMove(object sender, MouseEventArgs e)
{
    Pen pen1 = new System.Drawing.Pen(Color.Black, 3);
    Pen pen2 = new System.Drawing.Pen(panel1.BackColor, 3);
    Graphics g = panel1.CreateGraphics();
    g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
    // Clear the graphics, creating a blank area to draw on
    g.Clear(panel1.BackColor);
    g.DrawLine(pen1, new Point(0, 0), new Point(e.Location.X, e.Location.Y));
    x_previous = e.Location.X;
    y_previous = e.Location.Y;
}

希望这对您有所帮助!