Surface和SurfaceView以及SurfaceHolder的认识及使用

MainActivity如下:

package cn.testcleancanvas;
import android.os.Bundle;
import android.app.Activity;
/**
 * Demo描述:
 * 0 Surface和SurfaceView以及SurfaceHolder的认识及使用
 * 1 Canvas清屏的实现
 * 参考资料:

 * Thank you very much
 */
public class MainActivity extends Activity {
    private ImageMovingSurfaceView mImageMovingSurfaceView;
    private PhotoMovingSurfaceView mPhotoMovingSurfaceView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //方式一:
        mImageMovingSurfaceView=
        new ImageMovingSurfaceView(MainActivity.this);
        setContentView(mImageMovingSurfaceView);

        //方式二:
//      mPhotoMovingSurfaceView=
//      new PhotoMovingSurfaceView(MainActivity.this);
//      setContentView(mPhotoMovingSurfaceView);
    }

}

 

ImageMovingSurfaceView如下:

package cn.testcleancanvas;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuffXfermode;
import android.graphics.PorterDuff.Mode;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;
/**
 * 参考资料:

 * 
 * Thank you very much
 */
public class ImageMovingSurfaceView extends SurfaceView implements Callback {
  private int lastX=0;
  private Paint mPaint;
  private Bitmap mBitmap;
  private Canvas mCanvas;
  private boolean isSurfaceRun = true;
  private SurfaceHolder mSurfaceHolder;
  private DrawMovingImageThread mDrawMovingImageThread;

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

  private void init(){
    mPaint=new Paint();
    //SurfaceView的方法getHolder()
    mSurfaceHolder=this.getHolder();
    mSurfaceHolder.addCallback(this);
    mDrawMovingImageThread=new DrawMovingImageThread();
    mBitmap=BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
  }

  //开启线程不断地绘制Bitmap
  private class DrawMovingImageThread extends Thread{
    @Override
    public void run() {
      super.run();
      while (isSurfaceRun) {
        drawMovingImage();
        try {
          Thread.sleep(300);
        } catch (Exception e) {
          e.printStackTrace();
        }
      }
    }
  }

  private void drawMovingImage(){
    mCanvas=mSurfaceHolder.lockCanvas();
    if (mCanvas!=null) {
      //以下四行为清屏的核心代码:
      Paint paint = new Paint();
      paint.setXfermode(new PorterDuffXfermode(Mode.CLEAR));
      mCanvas.drawPaint(paint);
      paint.setXfermode(new PorterDuffXfermode(Mode.SRC));
      //在每次画之前先进行清屏
      mCanvas.drawBitmap(mBitmap, lastX, 40, mPaint);
      lastX+=20;
      if (lastX>=370) {
        lastX=0;
      }
      mSurfaceHolder.unlockCanvasAndPost(mCanvas);
    }
  }

  //以下三个方法为android.view.SurfaceHolder.Callback接口的实现
  @Override
  public void surfaceCreated(SurfaceHolder arg0) {
          mDrawMovingImageThread.start();
  }

  @Override
  public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {

  }

  @Override
  public void surfaceDestroyed(SurfaceHolder arg0) {
           isSurfaceRun=false;
  }

}

PhotoMovingSurfaceView如下:

package cn.testcleancanvas;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuffXfermode;
import android.graphics.PorterDuff.Mode;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;
/**
 * 参考资料:

 * 
 * Thank you very much
 */
public class PhotoMovingSurfaceView extends SurfaceView implements Callback {
  private int lastX=0;
  private Paint mPaint;
  private Bitmap mBitmap;
  private Canvas mCanvas;
  private boolean isSurfaceRun = true;
  private SurfaceHolder mSurfaceHolder;
  private DrawMovingImageThread mDrawMovingImageThread;

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

  private void init(){
    mPaint=new Paint();
    //SurfaceView的方法getHolder()
    mSurfaceHolder=this.getHolder();
    mSurfaceHolder.addCallback(this);
    mDrawMovingImageThread=new DrawMovingImageThread();
    mBitmap=BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
  }

  //开启线程不断地绘制Bitmap
  private class DrawMovingImageThread extends Thread{
    @Override
    public void run() {
      super.run();
      while (isSurfaceRun) {
        drawMovingImage();
        try {
          Thread.sleep(300);
        } catch (Exception e) {
          e.printStackTrace();
        }
      }
    }
  }

  private void drawMovingImage(){
    mCanvas=mSurfaceHolder.lockCanvas();
    if (mCanvas!=null) {
      //以下四行为清屏的核心代码:
      Paint paint = new Paint();
      paint.setXfermode(new PorterDuffXfermode(Mode.CLEAR));
      mCanvas.drawPaint(paint);
      paint.setXfermode(new PorterDuffXfermode(Mode.SRC));
      //在每次画之前先进行清屏
      mCanvas.drawBitmap(mBitmap, lastX, 40, mPaint);
      lastX+=20;
      if (lastX>=370) {
        lastX=0;
      }
      mSurfaceHolder.unlockCanvasAndPost(mCanvas);
    }
  }

  @Override
  protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    mDrawMovingImageThread.start();
  }

  //以下三个方法为android.view.SurfaceHolder.Callback接口的实现
  @Override
  public void surfaceCreated(SurfaceHolder holder) {
    //调用SurfaceView的onDraw()方法
    onDraw(null);
  }

  @Override
  public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {

  }

  @Override
  public void surfaceDestroyed(SurfaceHolder arg0) {
           isSurfaceRun=false;
  }

}

main.xml如下:

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
     >

</RelativeLayout>

 

 

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