Android自定义SurfaceView实现画板功能

<LinearLayout 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"  android:orientation="vertical" tools:context="com.example.xinxindemo.MainActivity" > <com.example.xinxindemo.view.SecondSurfaceView  android:id="@+id/surfaceview"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:layout_weight="20"   /> <LinearLayout  android:layout_width="match_parent"  android:layout_height="55dip"  android:orientation="horizontal"  android:padding="5dip" >  <Button   android:onClick="onClick"   android:layout_width="wrap_content"   android:layout_height="match_parent"   android:text="clean" /></LinearLayout></LinearLayout>

/** * 2016年7月26日17:20:13 * @author 小瓶盖 blog  * */public class SecondSurfaceView extends SurfaceView implements SurfaceHolder.Callback,Runnable{ /**  * 是否处于绘制状态  */ private boolean mIsDrawing; /**  * 帮助类  */ private SurfaceHolder mHolder; /**  * 画布  */ private Canvas mCanvas; /**  * 路径  */ private Path mPath; /**  * 画笔  */ private Paint mPaint; public SecondSurfaceView(Context context, AttributeSet attrs, int defStyle) {  super(context, attrs, defStyle);  initView(); } public SecondSurfaceView(Context context, AttributeSet attrs) {  super(context, attrs);  initView(); } public SecondSurfaceView(Context context) {  super(context);  initView(); } @Override public boolean onTouchEvent(MotionEvent event) {  int x=(int) event.getX();  int y=(int) event.getY();  switch (event.getAction()) {  case MotionEvent.ACTION_DOWN:   mPath.moveTo(x, y);   break;  case MotionEvent.ACTION_MOVE:   mPath.lineTo(x, y);   break;  case MotionEvent.ACTION_UP:   break;  default:   break;  }  return true; } private void initView() {  mHolder=getHolder();  mHolder.addCallback(this);  setFocusable(true);  setFocusableInTouchMode(true);  this.setKeepScreenOn(true);  mPath=new Path();  mPaint=new Paint();  mPaint.setAntiAlias(true);  mPaint.setColor(Color.BLACK);  mPaint.setStyle(Style.STROKE);  mPaint.setStrokeWidth(15); } @Override public void run() {  long start =System.currentTimeMillis();  while(mIsDrawing){   draw();  }  long end =System.currentTimeMillis();  if (end-start<100) {   try {    Thread.sleep(100-(end-start));   } catch (Exception e) {    e.printStackTrace();   }  } } @Override public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) { } @Override public void surfaceCreated(SurfaceHolder arg0) {  mIsDrawing=true;  new Thread(this).start(); } @Override public void surfaceDestroyed(SurfaceHolder arg0) {  mIsDrawing=false; } private void draw(){  try {   mCanvas=mHolder.lockCanvas();   mCanvas.drawColor(Color.WHITE);   mCanvas.drawPath(mPath, mPaint);  } catch (Exception e) {   e.printStackTrace();  }finally{   if (mCanvas!=null) {    mHolder.unlockCanvasAndPost(mCanvas);   }  } } /**  * 清除内容  */ public void clean(){  initView(); }}

/** * 2016年7月26日17:20:13 * @author 小瓶盖 blog * */public class MainActivity extends Activity{ SecondSurfaceView surfaceView; @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);  surfaceView=(SecondSurfaceView)findViewById(R.id.surfaceview); } public void onClick(View v){  surfaceView.clean(); }}