用GDI画文字中双缓存使用的问题

zsrui 2016-08-31 09:06:39

我想做一个支持弹幕的视频播放器，用GDI来实时画出弹幕内容。当我尝试使用双缓存机制来解决字幕的闪烁问题时，字幕反而不显示了，请高手指点下，谢谢！

弹幕内容是"我是画出来的文字！！！"

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;



namespace dmshipin

{

    public partial class Form1 : Form

    {

        //GDI画图的双缓存设定

        private BufferedGraphics graphBuffer = null;





        int danmuweizhi_x = 1500;//默认弹幕起始位置

        public Form1()

        {

            InitializeComponent();

            

        }



        private void axWindowsMediaPlayer1_Enter(object sender, EventArgs e)

        {

            

            axWindowsMediaPlayer1.currentPlaylist = axWindowsMediaPlayer1.newPlaylist("播放列表", "");

            //遍历打开的集合

            string[] bofangliebiao = new string[] { @"d:\h3.mp4", @"d:\h2.mp4", @"d:\h1.mp4" };

            foreach (string fn in bofangliebiao)

            {

                //添加播放列表

                axWindowsMediaPlayer1.currentPlaylist.appendItem(axWindowsMediaPlayer1.newMedia(fn));

            }



            //GDI画图的双缓存设定

            graphBuffer = (new BufferedGraphicsContext()).Allocate(axWindowsMediaPlayer1.CreateGraphics(), axWindowsMediaPlayer1.DisplayRectangle);

            

            //循环播放

            axWindowsMediaPlayer1.settings.setMode("loop", true);

            //播放

            axWindowsMediaPlayer1.Ctlcontrols.play();



            



        }



        private void timer1_Tick(object sender, EventArgs e)

        {

            System.Drawing.Size size = this.Size;

            System.Drawing.Point point = this.Location;



            int left = this.Left;

            int width = this.Width;



            if (danmuweizhi_x < -400)

            {

                danmuweizhi_x = width - 10;

            }

            else {

                danmuweizhi_x = danmuweizhi_x - 1;

            }

            label1.Location = new Point(danmuweizhi_x, 40);

            label2.Location = new Point(danmuweizhi_x + 10, 80);

            label3.Location = new Point(danmuweizhi_x - 5, 120);

            label4.Location = new Point(danmuweizhi_x + 20, 160);



            ////画出的文字

            //Graphics danmu = axWindowsMediaPlayer1.CreateGraphics();



            //GDI画图的双缓存设定

            Graphics danmu = graphBuffer.Graphics;

            Font font = new Font("黑体", 24);

            //Point一样，只是值是浮点类型

            PointF point1 = new PointF(danmuweizhi_x + 10, 250);

            SolidBrush grayBrush = new SolidBrush(Color.Gray);

            danmu.DrawString("我是画出来的文字！！！", font, Brushes.White, point1);

        }



    }

}