SurfaceView的基本使用流程

来源：互联网发布：企业价值衡量数据编辑：程序博客网时间：2024/05/21 17:38

好久没有写博客了，今天抽个空写篇简单的文章，主要就是来介绍一下SurfaceView的基本使用方法，并附上一个小DEMO供大家下载。废话不多说，直接上代码。
首先自定义了一个SurfaceView：

import android.content.Context;import android.graphics.Canvas;import android.graphics.Paint;import android.graphics.RectF;import android.view.SurfaceHolder;import android.view.SurfaceView;import com.yulin.animdemo.R;/** * Created by YuLinixon 2016/11/7 0007. */public class TestSurfaceView extends SurfaceView implements SurfaceHolder.Callback {    RenderThread renderThread;    SurfaceHolder holder;    Context context;    int lastAngle = 0;    int swipeAngle = 0;    RectF rectF;    Paint paint;    boolean isDraw = true;    private static final int sleepSpan = 50;    private static final int plusAngle = 10;    public TestSurfaceView(Context context) {        super(context);        this.context = context;        holder = this.getHolder();        holder.addCallback(this);        renderThread = new RenderThread();    }    @Override    public void surfaceCreated(SurfaceHolder holder) {        isDraw = true;        paint = new Paint();        paint.setDither(true);        paint.setAntiAlias(true);        paint.setStrokeWidth(5);        paint.setStyle(Paint.Style.STROKE);        paint.setColor(context.getResources().getColor(R.color.colorAccent));        rectF = new RectF(getWidth() / 4, getWidth() / 4, getWidth() / 4 * 3, getWidth() / 4 * 3);        renderThread.start();    }    @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {    }    @Override    public void surfaceDestroyed(SurfaceHolder holder) {        isDraw = false;    }    private class RenderThread extends Thread {        @Override        public void run() {            while (true) {                doDraw();                try {                    Thread.sleep(sleepSpan);                } catch (Exception e) {                    e.printStackTrace();                }                lastAngle = swipeAngle;                swipeAngle += plusAngle;            }        }    }    private void doDraw() {        Canvas canvas = holder.lockCanvas();        try {//            canvas.drawArc(rectF, lastAngle, swipeAngle, false, paint);            canvas.drawArc(rectF, lastAngle, swipeAngle, true, paint);        } catch (Exception e) {            e.printStackTrace();        } finally {            holder.unlockCanvasAndPost(canvas);        }    }}

然后是在Activity中的使用：

public class MainActivity extends AppCompatActivity implements View.OnClickListener{    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        TestSurfaceView surfaceView = new TestSurfaceView(this);        setContentView(surfaceView);    } }

最后是显示效果:
效果图
最后了解一下SurfaceView的基本使流程：
1.获取到 SurfaceView 对应的 SurfaceHolder，并且要给 SurfaceHolder 添加一个 SurfaceHolder.callback 对象。
2.创建一个线程用于渲染视图；
3.在SurfaceHolder.callback的surfaceCreated方法中开始渲染视图，绘制结束后，SurfaceHolder.callback的surfaceDestroyed方法中使用 unlockCanvasAndPost方法解锁 Canvas。
感觉是不是很简单？最后附上这个Demo的源码下载地址:

DEMO下载地址

1 0