SurfaceView双缓冲技术引入

最新推荐文章于 2025-09-05 16:34:31 发布

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最新推荐文章于 2025-09-05 16:34:31 发布

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CC 4.0 BY-SA版权

文章标签：移动开发

原文链接：http://www.cnblogs.com/loaderman/p/10232168.html

本文介绍了一种使用双缓冲技术优化Android自定义View绘制过程的方法。通过创建DoubleBufferingTextView类，利用SurfaceView和Canvas进行高效绘图，避免了屏幕闪烁，提升了用户体验。文章展示了如何在SurfaceHolder.Callback中实现文本绘制，并通过多线程更新显示内容。

package com.loaderman.customviewdemo;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;


public class DoubleBufferingTextView extends SurfaceView {
    private Paint mPaint;

    public DoubleBufferingTextView(Context context) {
        super(context);
        init();
    }

    public DoubleBufferingTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public DoubleBufferingTextView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    private void init() {
        mPaint = new Paint();
        mPaint.setColor(Color.RED);
        mPaint.setTextSize(30);

        getHolder().addCallback(new SurfaceHolder.Callback() {
            @Override
            public void surfaceCreated(SurfaceHolder holder) {

                drawText(holder);
            }

            @Override
            public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

            }

            @Override
            public void surfaceDestroyed(SurfaceHolder holder) {

            }
        });
    }

    private void drawText(final SurfaceHolder holder) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                for (int i = 0; i < 10; i++) {
                    Canvas canvas = holder.lockCanvas();
                    if (canvas != null) {
                        canvas.drawText(i + "", i * 30, 50, mPaint);
                    }
                    holder.unlockCanvasAndPost(canvas);

                    try {
                        Thread.sleep(800);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        }).start();
    }

}