android 雙擊圖片放大，再雙擊縮小效果 【安卓進化九】

       今天寫了個onDoubleTap事件的處理方法，雙擊螢幕事件的放大縮小的程式，雙擊螢幕圖片放大，再雙擊螢幕圖片縮小到原來的效果。 請看的效果！                

                                           原圖：                                                     雙擊螢幕放大後的效果： 

                                       

現把代碼貼出來：

一、MainActivty.java類中的代碼：

package com.cn.android;import android.app.Activity;import android.os.Bundle;import android.util.Log;import android.view.GestureDetector;import android.view.KeyEvent;import android.view.MotionEvent;import android.view.GestureDetector.OnGestureListener;public class mainActivity extends Activity implements OnGestureListener{       private ImageShowView mImageShowView = null;    private GestureDetector gestureScanner;    private double Scale = 1.0;        @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);                mImageShowView = new ImageShowView(this);        setContentView(mImageShowView);                   gestureScanner = new GestureDetector(this);           gestureScanner.setOnDoubleTapListener(new GestureDetector.OnDoubleTapListener(){            @Override            public boolean onDoubleTap(MotionEvent e) {                // TODO Auto-generated method stub                // 雙擊時產生一次                                    if(Scale == 1.0){                    Scale = Scale + 0.5;                    mImageShowView.setScale(Scale);                }                else if(Scale == 1.5){                    Scale = Scale - 0.5;                    mImageShowView.setScale(Scale);                }                Log.v("daming", "onDoubleTap");                return true;            }            @Override            public boolean onDoubleTapEvent(MotionEvent e) {                // TODO Auto-generated method stub                // 雙擊時產生兩次                Log.v("daming", "onDoubleTapEvent");                return false;            }            @Override            public boolean onSingleTapConfirmed(MotionEvent e) {                //短快的點擊算一次單擊                Log.v("daming", "onSingleTapConfirmed");                return false;              }             });    }        @Override      public boolean onTouchEvent(MotionEvent me) {         return gestureScanner.onTouchEvent(me);       }    @Override    public boolean onDown(MotionEvent e) {        // TODO Auto-generated method stub        return false;    }    @Override    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,            float velocityY) {        // TODO Auto-generated method stub        return false;    }    @Override    public void onLongPress(MotionEvent e) {        // TODO Auto-generated method stub            }    @Override    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,            float distanceY) {        // TODO Auto-generated method stub        return false;    }    @Override    public void onShowPress(MotionEvent e) {        // TODO Auto-generated method stub            }    @Override    public boolean onSingleTapUp(MotionEvent e) {        // TODO Auto-generated method stub        return false;    }     }

二、ImageShowView.java中的代碼：

package com.cn.android;import android.content.Context;import android.graphics.Bitmap;import android.graphics.Canvas;import android.graphics.Matrix;import android.graphics.drawable.BitmapDrawable;import android.view.KeyEvent;import android.view.View;public class ImageShowView extends View implements Runnable{    Bitmap mBitmap = null;    int mBitmapWidth = 0;//定義圖片的寬    int mBitmapHeight = 0;//定義圖片的高        private double Scale = 1.0;        Matrix mMatrix = new Matrix();        public ImageShowView(Context context) {        super(context);                mBitmap = ((BitmapDrawable)getResources().getDrawable(R.drawable.image1)).getBitmap();                mBitmapWidth = mBitmap.getWidth();        mBitmapHeight = mBitmap.getHeight();                //開啟線程        new Thread(this).start();    }    public void setScale(double scale){         this.Scale = scale;    }        @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        mMatrix.reset();        mMatrix.postScale((float)Scale, (float)Scale);//設定縮放                Bitmap mBitmap2 = Bitmap.createBitmap(mBitmap,0,0,mBitmapWidth,mBitmapHeight,mMatrix,true);                //繪製旋轉之後的映像        ImageShowView.drawImage(canvas,mBitmap2,(320-mBitmapWidth)/2,10);        mBitmap2 = null;    }    @Override    public void run() {                while(!Thread.currentThread().isInterrupted()){            try {                Thread.sleep(100);            } catch (InterruptedException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }            postInvalidate();        }        }        private static void drawImage(Canvas canvas, Bitmap bitmap, int x, int y) {        // TODO Auto-generated method stub        canvas.drawBitmap(bitmap, x, y, null);    }}

說明：以上就是我的全部代碼，項目中的圖片就不上傳了，大家可以自己傳個圖片上去就可以了，有需要完整代碼的可以留郵箱，大家有任何問題，可以給我留言，我看到就回複！大家有好的意見可以提出來，共同學習，共同進步！