会动的爆米花

最新推荐文章于 2024-06-22 10:14:14 发布

翻译最新推荐文章于 2024-06-22 10:14:14 发布 · 235 阅读

本文介绍了一个名为BoomFlowerView的自定义视图组件，该组件通过继承SurfaceView并实现SurfaceHolder.Callback接口来创建一个能显示动态跳舞爆米花效果的应用。BoomFlowerView利用DrawThread线程不断更新画布上的图片，从而实现动画效果。

package alice.bw.com.day03surfaceview.view;

import android.content.Context;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

import java.io.IOException;
import java.io.InputStream;

/**
 * 会跳舞的爆米花
 */
// 继承surfaceView 并实现接口
public class BoomFlowerView extends SurfaceView implements SurfaceHolder.Callback {
    private SurfaceHolder holder;
    private DrawThread thread;

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


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

    // 实例化surfaceHolder  并添加监听 并实例化 绘制线程
    private void init() {
        holder = getHolder();
        holder.addCallback(this);
        thread = new DrawThread();

    }

    @Override
    public void surfaceCreated(SurfaceHolder surfaceHolder) {
        //启动绘制线程
        thread.start();
    }

    @Override
    public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder surfaceHolder) {

    }

    class DrawThread extends Thread {
        @Override
        public void run() {
            super.run();
            //获取资源管理者
            AssetManager manager = getResources().getAssets();
            Paint paint = new Paint();//实例化画笔
            int i = 1;
            while (true) {

                String fileName = null;
                //获取 画布  锁定画布
                Canvas canvas = holder.lockCanvas();
        // 获取文件名称
                if (i >= 10)
                    fileName = "loading00" + i + ".png";
                else
                    fileName = "loading000" + i + ".png";
                InputStream stream = null;
                try {
                    // 读取文件流
                    stream = manager.open(fileName);
                    // 将流转换为  Bitmap
                    Bitmap bitmap = BitmapFactory.decodeStream(stream);
                    if(canvas!=null){
                        canvas.drawColor(Color.BLACK);//设置一下画布的颜色
                        //绘制  一个bitmap
                        canvas.drawBitmap(bitmap, 100, 100, paint);
                        //解锁画布并提交
                        holder.unlockCanvasAndPost(canvas);
                    }

                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                    if (stream != null) {
                        try {
                            // 关闭流
                            stream.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
                // 叠加i  如果大于26  循环
                i++;
                if (i > 26) {
                    i = 1;
                }
            }

        }
    }
}