C#中动态删除/添加（取消删除）表单区域

Question

如何使用区域和图形路径类动态删除/添加（取消删除）表单区域

Answer 1

要动态更改表单的形状，只需将表单的 Region 属性设置为从 GraphicsPath 创建的新 Region 对象即可。例如，带有单个按钮的表单可以更改其形状，如下所示：（工作示例）

using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;

namespace Sample
{
    public class ShapedForm : Form
    {
        Button testbutton;

        public ShapedForm()
        {
            // Create a button.
            testbutton = new Button();
            testbutton.Location = new Point(10, 10);
            testbutton.Size = new Size(50, 50);
            testbutton.Text = "Click me!";
            testbutton.Click += new EventHandler(this.testbutton_Click);
            this.Controls.Add(testbutton);

            // Remove the border around the form.
            this.FormBorderStyle = FormBorderStyle.None;

            // Set the initial shape of the form to an ellipse.
            GraphicsPath path = new GraphicsPath();
            path.AddEllipse(0, 0, 200, 100);

            this.Region = new Region(path);
        }

        private void testbutton_Click(object sender, EventArgs e)
        {
            // Change the shape of the form to some other ellipse.
            GraphicsPath path = new GraphicsPath();
            path.AddEllipse(0, 0, 100, 100);
            path.AddEllipse(120, 40, 50, 50);

            this.Region = new Region(path);
        }
    }
}