C# 喷漆/仅喷漆时的奇怪行为

我有一个网格和一个四边形。网格在其中布局为四边形

class Grid : System.Windows.Forms.Control
    {
        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);
        }

        protected override void OnLayout(LayoutEventArgs levent)
        {
            base.OnLayout(levent);

            int numControls = this.Controls.Count;

            if (numControls < 1)
            {
                return;
            }

            int size = this.Width / numControls;

            int i = 0;

            foreach (Control ctrl in this.Controls)
            {
                ctrl.Size = new Size(size, this.Height);
                ctrl.Location = new Point(i * size, 0);
                i++;
            }
        }
}

以我的形式

        this.quad1 = new Quad();
        this.SuspendLayout();

        grid1 = new Grid();
        grid1.Size = new Size(200, 200);

        for (int i = 0; i < 4; i++)
        {
            Grid grid_j = new Grid();
            for (int j = 0; j < 4; j++)
            {
                grid_j.Controls.Add(new Quad());
            }
            grid1.Controls.Add(grid_j);
        }

        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.ClientSize = new System.Drawing.Size(284, 261);
        this.Controls.Add(grid1);
        this.Name = "Form1";
        this.Text = "Form1";
        this.ResumeLayout(false);

protected override void OnLayout(System.Windows.Forms.LayoutEventArgs levent)
        {
             base.OnLayout(levent);

             this.grid1.Size = new Size(this.ClientRectangle.Width, this.ClientRectangle.Height);
             this.grid1.Location = new Point(0, 0);
        }

---

这是正确的方法吗？另外，何时必须调用进一步的“更新”

Invalidate（）

告诉控件自行重新绘制，并且在

OnPaint

之前图形不会被清除。Invalidate是否会传播到子级？（它会传播给父母吗？）我相信ti会传播给孩子（而不是父母）。我不是100%确定，但你可以用一个简单的绘图来测试。默认情况下，绘图是优化的，只重绘控件调整大小时显示的部分。换句话说，它不会覆盖矩形的一条边，从而产生涂抹效果。此行为由ControlStyles.ResizerDraw样式控制。对于控件，默认情况下它处于禁用状态。打开它最简单的方法是添加

this.ResizeRedraw=true到四元类构造函数。这增加了明显闪烁的几率，如果这是一个问题，那么也添加
This.DoubleBuffered=true
        this.quad1 = new Quad();
        this.SuspendLayout();

        grid1 = new Grid();
        grid1.Size = new Size(200, 200);

        for (int i = 0; i < 4; i++)
        {
            Grid grid_j = new Grid();
            for (int j = 0; j < 4; j++)
            {
                grid_j.Controls.Add(new Quad());
            }
            grid1.Controls.Add(grid_j);
        }

        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.ClientSize = new System.Drawing.Size(284, 261);
        this.Controls.Add(grid1);
        this.Name = "Form1";
        this.Text = "Form1";
        this.ResumeLayout(false);

protected override void OnLayout(System.Windows.Forms.LayoutEventArgs levent)
        {
             base.OnLayout(levent);

             this.grid1.Size = new Size(this.ClientRectangle.Width, this.ClientRectangle.Height);
             this.grid1.Location = new Point(0, 0);
        }

foreach (Control ctrl in this.Controls)
            {
                ctrl.Size = new Size(size, this.ClientRectangle.Height-10);
                ctrl.Location = new Point(i * size, 0);
                ctrl.Invalidate();
                i++;
            }