4、通過手勢縮放圖片參考

1、通過手勢縮放【實驗內(nèi)容】通過手勢縮放【實驗?zāi)康摹空莆帐謩菔录奶幚矸椒?。【實驗】開源平板，Android4.0 環(huán)境?！娟P(guān)鍵代碼】1源文件：Main.java ： package.farsight.gesture; import android.app.Activity; import android.os.Bundle;import android.view.GestureDetector;import android.view.GestureDetector.OnGestureListener; import android.view.MotionEvent;import android.

2、widget.ImageView;public class Main extendivity implements OnGestureListener private GestureDetectestureScanner;/* Called when the activity iscreated. */ Overridepublic void onCreate(Bundle savedInstane) super.onCreate(savedInstane); setContentView(R.layout.main);ImageView iv = (ImageView) findViewBy

3、Id(R.id.imageView1); iv.setOnTouchListener(new MultiTouchPoListener(); gestureScanner = new GestureDetector(this);gestureScanner.setOnDoubleTapListener(new GestureDetector.OnDoubleTapListener() publiconDoubleTap(MotionEvent e) / TODO 雙擊時產(chǎn)生一次時，調(diào)至編輯頁面android.util.Log.e(asd, asdf); return false;Overrid

4、epubliconDoubleTvent(MotionEvent e) / TODO Auto-generated method stubreturn false;OverridepubliconSingleTapConfirmed(MotionEvent e) / TODO Auto-generated method stubreturn false;);Override publiconTouchEvent(MotionEvent me)return gestureScanner.onTouchEvent(me);Override publiconDown(MotionEvent e) /

5、 TODO Auto-generated method stubreturn false;OverridepubliconFling(MotionEvent e1, MotionEvent e2, float velocityX,float velocityY) / TODO Auto-generated method stub return false;Overridepublic void onLongPress(MotionEvent e) / TODO Auto-generated method stubOverridepubliconScroll(MotionEvent e1, Mo

6、tionEvent e2, float distanceX,float distanceY) / TODO Auto-generated method stub2return false;Overridepublic void onShowPress(MotionEvent e) / TODO Auto-generated method stubOverridepubliconSingleTapUp(MotionEvent e) / TODO Auto-generated method stubreturn false;源文件：MultiTouchPoListener.java ：packag

7、e.farsight.gesture;import android.graphics.Matrix; import android.graphics.PoF; import android.util.FloatMath; import android.view.MotionEvent; import android.view.View;import android.view.View.OnTouchListener;import android.widget.ImageView;public class MultiTouchPoListener implements OnTouchListen

8、er Matrix matrix = new Matrix();Matrix savedMatrix = new Matrix();s ssic final ic finalic finalNONE = 0;DRAG = 1;ZOOM = 2;mode = NONE;PoF start = new PoF();PoF mid = new PoF(); float oldDist = 1f;OverridepubliconTouch(View v, MotionEvent event) 3ImageView view = (ImageView) v;switch (event.getAction

9、() & MotionEvent.ACTION_MASK) case MotionEvent.ACTION_DOWN:matrix.set(view.getImageMatrix(); savedMatrix.set(matrix); start.set(event.getX(), event.getY();mode = DRAG;break;case MotionEvent.ACTION_POER_DOWN: oldDist = spacing(event);if (oldDist 10f) savedMatrix.set(matrix); midPo(mid, event); mode =

10、 ZOOM;break;case MotionEvent.ACTION_UP:case MotionEvent.ACTION_POmode = NONE;ER_UP:break;case MotionEvent.ACTION_MOVE: if (mode = DRAG) matrix.set(savedMatrix);matrix.tTranslate(event.getX() - start.x, event.getY()- start.y); else if (mode = ZOOM) float newDist = spacing(event); if (newDist 10f) matrix.set(savedMatrix);float scale = newDist / oldDist;matrix.tScale(scale, scale, mid.x, mid.y);break;view.setImageMatrix(matrix);4【實驗現(xiàn)象】5return true;private float spacing(MotionEvent event) float x = event.getX(0) - event.getX(1); float y = event.getY(0) - event.getY(1); return FloatM