【转】C# GDI+ 图像的双缓存技术

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;

namespace DoubleBuffer

{

public partial class Form1 : Form

{

bool flag = true;

Brush brush;

public Form1()

{

InitializeComponent();

}

private void timerTest_Tick(object sender, EventArgs e)

{

if (rbYes.Checked)//默认

{

BasicDraw();

}

if(rbUser.Checked)//自己实现双缓冲原理

UseMyImage();

if (rbManual.Checked)//手动管理双缓冲

{

UseDoubleBuffer();

}

}

private void BasicDraw()

{

DateTime t1 = DateTime.Now;

Graphics g = this.CreateGraphics();

Draw(g);

DateTime t2 = DateTime.Now;

TimeSpan sp = t2 - t1;

float per = 1000 / sp.Milliseconds;

lbSpeed.Text = "速度：" + per.ToString() + "帧/秒";

}

private void UseMyImage()

{

DateTime t1 = DateTime.Now;

Bitmap bmp = new Bitmap(600, 600);

Graphics g = Graphics.FromImage(bmp);

Draw(g);

this.CreateGraphics().DrawImage(bmp, 0, 0);

DateTime t2 = DateTime.Now;

TimeSpan sp = t2 - t1;

float per = 1000 / sp.Milliseconds;

lbSpeed.Text = "速度：" + per.ToString() + "帧/秒";

}

private void UseDoubleBuffer()

{

BufferedGraphicsContext currentContext = BufferedGraphicsManager.Current;

BufferedGraphics myBuffer = currentContext.Allocate(this.CreateGraphics(), this.DisplayRectangle);

DateTime t1 = DateTime.Now;

Graphics g = myBuffer.Graphics;

g.Clear(Button.DefaultBackColor);

Draw(g);

myBuffer.Render();

DateTime t2 = DateTime.Now;

TimeSpan sp = t2 - t1;

float per = 1000 / sp.Milliseconds;

lbSpeed.Text = "速度：" + per.ToString() + "帧/秒";

myBuffer.Dispose();

}

private void Draw(Graphics g)

{

if (flag)

{

brush = new LinearGradientBrush(new PointF(0.0f, 0.0f),

new PointF(700.0f, 300.0f), Color.Red, Color.Blue);

flag = false;

}

else

{

brush = new LinearGradientBrush(new PointF(0.0f, 0.0f),

new PointF(700.0f, 300.0f), Color.Blue, Color.Red);

flag = true;

}

for (int j = 0; j < 60; j++)

{

for (int i = 0; i < 60; i++)

{

g.FillEllipse(brush, i * 10, j * 10, 10, 10);

}

}

}

private void btnStart_Click(object sender, EventArgs e)

{

timerTest.Enabled = true;

}

private void btnStop_Click(object sender, EventArgs e)

{

timerTest.Enabled = false;

}

}

}