安卓大图片不失真拉拽放大缩小

这些天都在搞图片处理，要求显示大图（2m以上）都知道安卓应用默认加载的图片大小是不能太大的，如果太大的话就会内存溢出。而且不能压缩失真，其实android自带的一些控件是能实现拖拽的但都不符合我的需求，于是在网上找答案，还是有点眉目的就是没有和我一模一样的需求，于是那过来比对修改搞来了半天，终于还是出来效果了。还是相信那么一句话，没有白费的功夫。有付出还是会有回报的。现在为了和我一样需求的人不至于乱费时间，我把源码贴出来共享一下。

package com.hcq.jpg; import java.io.InputStream;import android.annotation.SuppressLint;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Matrix;import android.graphics.PointF;import android.os.Bundle;import android.os.Handler;import android.view.Menu;import android.view.MotionEvent;import android.view.View;import android.view.View.OnTouchListener;import android.view.ViewConfiguration;import android.view.ViewGroup.LayoutParams;import android.view.Window;import android.view.WindowManager;import android.widget.ImageView;import android.widget.ImageView.ScaleType; @SuppressLint("NewApi")public class Main extends Activity {    ImageView iv;    float  lastX ,lastY;    int globalX, globalY;    int globalWidth, globalHeight;    final Handler handler = new Handler();    Bitmap png = null;    float mTouchSlop;    private ZoomImageView zoomImageView;    private boolean mIsDragging;    Runnable mSetBitmap = new Runnable() {                 @Override        public void run() {           // setImage();        }    };    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        requestWindowFeature(Window.FEATURE_NO_TITLE);        setContentView(R.layout.main);        final Window win = getWindow();        win.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,  WindowManager.LayoutParams.FLAG_FULLSCREEN);        iv = new ImageView(this);        iv.setAdjustViewBounds(true);        iv.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT));        iv.setScaleType(ScaleType.CENTER);        width = iv.getWidth();        height = iv.getHeight();//setContentView(iv);        iv.setOnTouchListener(new MulitPointTouchListener());                zoomImageView = (ZoomImageView) findViewById(R.id.zoom_image_view);// 取出图片路径，并解析成Bitmap对象，然后在ZoomImageView中显示//String imagePath = getIntent().getStringExtra("image_path");InputStream is = getResources().openRawResource(R.drawable.ta);        png = BitmapFactory.decodeStream(is);//bitmap = BitmapFactory.decodeFile(imagePath);zoomImageView.setImageBitmap(png);        new Thread(){            @Override            public void run() {                super.run();                try {                InputStream is = getResources().openRawResource(R.drawable.one);                    png = BitmapFactory.decodeStream(is);                    handler.post(mSetBitmap);                } catch (Exception e) {                    e.printStackTrace();                }            }}.start();            final ViewConfiguration configuration = ViewConfiguration.get(getApplicationContext());mTouchSlop = configuration.getScaledTouchSlop();    }     void setImage() {        if(png != null) {            iv.setImageBitmap(png);            globalWidth = png.getWidth();            globalHeight = png.getHeight();          handler.removeCallbacks(mSetBitmap);            iv.setScaleType(ScaleType.MATRIX);            iv.setImageMatrix(iv.getImageMatrix());        }    }              @Override    public boolean onCreateOptionsMenu(Menu menu) {        getMenuInflater().inflate(R.menu.main, menu);        return true;    }         public class MulitPointTouchListener implements OnTouchListener {        Matrix matrix = new Matrix();        Matrix savedMatrix = new Matrix();        PointF pf = new PointF();        float mx, my;        public MulitPointTouchListener() {            super();        }        @Override        public boolean onTouch(View v, MotionEvent event) {            ImageView view = (ImageView) v;            float dx = event.getX() - lastX,dy = event.getX() -  lastY;            switch(event.getAction() & MotionEvent.ACTION_MASK) {            case MotionEvent.ACTION_DOWN:                matrix.set(view.getImageMatrix());                savedMatrix.set(matrix);                pf.set(event.getX(), event.getY());                mIsDragging =false;                break;            case MotionEvent.ACTION_MOVE:                            matrix.set(savedMatrix);//                mx = event.getX() - pf.x;//                my = event.getY() - pf.y;//                globalX += mx;//                globalY += my;//                lastX = event.getX();//                lastY = event.getY();//                matrix.postTranslate(mx, my);//                Log.i("MXY", pf.x + "," + pf.y + "," + mx + "," + my + "," + view.getWidth() + "," + view.getHeight());             // 只有单指按在屏幕上移动时，为拖动状态float xMove = event.getX();float yMove = event.getY();if (lastXMove == -1 && lastYMove == -1) {lastXMove = xMove;lastYMove = yMove;}movedDistanceX = xMove - lastXMove;movedDistanceY = yMove - lastYMove;// 进行边界检查，不允许将图片拖出边界if (totalTranslateX + movedDistanceX > 0) {movedDistanceX = 0;} else if (width - (totalTranslateX + movedDistanceX) > globalWidth) {movedDistanceX = 0;}if (totalTranslateY + movedDistanceY > 0) {movedDistanceY = 0;} else if (height - (totalTranslateY + movedDistanceY) > globalHeight) {movedDistanceY = 0;}// 调用onDraw()方法绘制图片lastXMove = xMove;lastYMove = yMove;matrix.postTranslate(movedDistanceX, movedDistanceY);view.setImageMatrix(matrix);                break;                 default:                    break;            }                        return true;        }             }    /** * 记录当前图片的宽度，图片被缩放时，这个值会一起变动 */private float currentBitmapWidth;/** * 记录当前图片的高度，图片被缩放时，这个值会一起变动 */private float currentBitmapHeight;/** * ZoomImageView控件的宽度 */private int width;/** * ZoomImageView控件的高度 */private int height;    /** * 记录上次手指移动时的横坐标 */private float lastXMove = -1;/** * 记录上次手指移动时的纵坐标 */private float lastYMove = -1;/** * 记录手指在横坐标方向上的移动距离 */private float movedDistanceX;/** * 记录手指在纵坐标方向上的移动距离 */private float movedDistanceY;/** * 记录图片在矩阵上的横向偏移值 */private float totalTranslateX;/** * 记录图片在矩阵上的纵向偏移值 */private float totalTranslateY ;    @Override    protected void onStop() {        if (png != null) {            if (!png.isRecycled()) {                png.recycle();                png = null;                System.gc();             }        }        super.onStop();    }     @Override    protected void onDestroy() {        super.onDestroy();        if (png != null) {            if (!png.isRecycled()) {                png.recycle();                 png = null;                System.gc();             }        }    }}