视频叠加半透明圆

在视频上叠加半透明圆

 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;
using System.Runtime.InteropServices;

namespace WindowsApplication132
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            GraphicsPath GP = new GraphicsPath();
            GP.AddEllipse(new Rectangle(0, 0, 50, 50));

            Bitmap Bmp = new Bitmap(50, 50);
            using (Graphics G = Graphics.FromImage(Bmp))
                G.FillEllipse(Brushes.Red, new Rectangle(0, 0, 50, 50));

            Panel P = new Panel();
            P.Name = "P";
            P.BorderStyle = BorderStyle.Fixed3D;
            P.Parent = this;
       

            Form F = new Form();
            F.Name = "F";
            F.Size = new Size(50, 50);
            F.FormBorderStyle = FormBorderStyle.None;
            F.BackgroundImage = Bmp;
            F.Opacity = 0.5;
            F.Region = new Region(GP);
            F.Show(P);
            this.LocationChanged += new EventHandler(Form1_LocationChanged);
        }

        void Form1_LocationChanged(object sender, EventArgs e)
        {
            Panel P = (Panel)this.Controls.Find("P", true)[0];
            Application.OpenForms["F"].Location = P.PointToScreen(new Point(0, 0));
        }
    }
}