<?xml version="1.0" encoding="utf-8"?> <LinearLayout   xmlns:android="http://schemas.android.com/apk/res/android"   android:orientation="vertical"   android:layout_width="match_parent"   android:layout_height="match_parent">     <FrameLayout         android:layout_height="fill_parent"         android:layout_width="fill_parent">         <ImageView             android:id="@+id/view_img"             android:layout_height="fill_parent"             android:layout_width="fill_parent"             android:background="@drawable/camera_gray"/>         <ImageButton             android:id="@+id/view_close"             android:layout_height="wrap_content"             android:layout_width="wrap_content"             android:layout_gravity="top|left"             android:layout_margin="5dip"/>         <ImageButton             android:id="@+id/view_del"             android:layout_height="wrap_content"             android:layout_width="wrap_content"             android:layout_gravity="top|right"             android:layout_margin="5dip"/>         <ImageButton             android:id="@+id/view_narrow"             android:layout_height="wrap_content"             android:layout_width="wrap_content"             android:layout_gravity="bottom|center_horizontal"             android:layout_marginRight="10dip"/>         <ImageButton             android:id="@+id/view_amplification"             android:layout_height="wrap_content"             android:layout_width="wrap_content"             android:layout_gravity="bottom|center_horizontal"             android:layout_marginLeft="10dip"/>     </FrameLayout> </LinearLayout>

package com.kotei.lbs.Anthurium.LawCases; import android.app.Activity; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Matrix; import android.graphics.PointF; import android.graphics.RectF; import android.os.Bundle; import android.util.DisplayMetrics; import android.util.FloatMath; import android.util.Log; import android.view.MotionEvent; import android.view.View; import android.view.Window; import android.view.View.OnTouchListener; import android.widget.ImageView; import android.widget.ImageView.ScaleType; /**  * 查看图片的操作  * @author hongj  */ public class GalleryViewTouch extends Activity  {     private ImageView iv;      private Bitmap bitmap=null;         Matrix matrix = new Matrix();         Matrix savedMatrix = new Matrix();         DisplayMetrics dm;         float minScaleR;// 最小缩放比例         static final float MAX_SCALE = 4f;// 最大缩放比例         static final int NONE = 0;// 初始状态         static final int DRAG = 1;// 拖动         static final int ZOOM = 2;// 缩放         int mode = NONE;         PointF prev = new PointF();         PointF mid = new PointF();         float dist = 1f;     /** Called when the activity is first created. */     @Override     public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         requestWindowFeature(Window.FEATURE_NO_TITLE);         setContentView(R.layout.view_show);         dm = new DisplayMetrics();         getWindowManager().getDefaultDisplay().getMetrics(dm);// 获取分辨率         bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.bottom_layout_background);         iv=(ImageView)findViewById(R.id.view_img);         iv.setImageBitmap(bitmap);         iv.setOnTouchListener(new ImageTouch(bitmap,dm.widthPixels,dm.heightPixels,iv));     }     class ImageTouch implements OnTouchListener {         private ImageView iv;          private Bitmap bitmap=null;             Matrix matrix = new Matrix();             Matrix savedMatrix = new Matrix();             int dmwidth,dmheight;             float minScaleR;// 最小缩放比例             static final float MAX_SCALE = 4f;// 最大缩放比例             static final int NONE = 0;// 初始状态             static final int DRAG = 1;// 拖动             static final int ZOOM = 2;// 缩放             int mode = NONE;             PointF prev = new PointF();             PointF mid = new PointF();             float dist = 1f;             ImageTouch(Bitmap bitmap,int width,int height,ImageView iv){                 this.bitmap= bitmap;                 this.dmwidth=width;                 this.dmheight=height;                 this.iv=iv;                 initImage();             }             public void initImage(){                 if (dmwidth < bitmap.getWidth()|| dmheight < bitmap.getHeight()) {                     minZoom();                     center();                     iv.setImageMatrix(matrix);                 } else {                     iv.setScaleType(ScaleType.CENTER);                 }             }         @Override         public boolean onTouch(View v, MotionEvent event) {              switch (event.getAction() & MotionEvent.ACTION_MASK) {                 // 主点按下                 case MotionEvent.ACTION_DOWN:                     Log.d("System.out", "ACTION_DOWN");                     savedMatrix.set(matrix);                     prev.set(event.getX(), event.getY());                     mode = DRAG;                     break; // 副点按下                 case MotionEvent.ACTION_POINTER_DOWN:                     Log.d("System.out", "ACTION_POINTER_DOWN");                     dist = spacing(event); // 如果连续两点距离大于10，则判定为多点模式                     if (spacing(event) > 10f) {                         savedMatrix.set(matrix);                         midPoint(mid, event);                         mode = ZOOM;                     }                     break;                 case MotionEvent.ACTION_UP:                 case MotionEvent.ACTION_POINTER_UP:                     mode = NONE;                     break;                 case MotionEvent.ACTION_MOVE:                     if (mode == DRAG) {                         matrix.set(savedMatrix);                         matrix.postTranslate(event.getX() - prev.x, event.getY()                                 - prev.y);                     } else if (mode == ZOOM) {                         float newDist = spacing(event);                         if (newDist > 10f) {                             matrix.set(savedMatrix);                             float tScale = newDist / dist;                             matrix.postScale(tScale, tScale, mid.x, mid.y);                         }                     }                     break;                 }                 iv.setImageMatrix(matrix);                 if(mode!=NONE)                CheckView();                 return true;         }          private void CheckView() {                 float p[] = new float[9];                 matrix.getValues(p);                 if (mode == ZOOM) {                     if (p[0] < minScaleR) {                         matrix.setScale(minScaleR, minScaleR);                     }                     if (p[0] > MAX_SCALE) {                         matrix.set(savedMatrix);                     }                 }                 center();             }          public void minZoom() {                 Log.i("test", bitmap.getWidth()+"");                 Log.i("test", bitmap.getHeight()+"");                 minScaleR = Math.min(                         (float) dmwidth / (float) bitmap.getWidth(),                         (float) dmheight / (float) bitmap.getHeight());                 if (minScaleR < 1.0) {                     matrix.postScale(minScaleR, minScaleR);                 }             }           protected void center(boolean horizontal, boolean vertical) {                 Matrix m = new Matrix();                 m.set(matrix);                 RectF rect = new RectF(0, 0, bitmap.getWidth(), bitmap.getHeight());                 m.mapRect(rect);                 float height = rect.height();                 float width = rect.width();                 Log.d("System.out",rect.top+"************"+ rect.bottom);                 float deltaX = 0, deltaY = 0;                 if (vertical) { // 图片小于屏幕大小，则居中显示。大于屏幕，上方留空则往上移，下方留空则往下移                     int screenHeight = dmheight;                     if (height < screenHeight) {                         deltaY = (screenHeight - height) / 2 - rect.top;                     } else if (rect.top > 0) {                         deltaY = -rect.top;                     } else if (rect.bottom < screenHeight) {                         deltaY = iv.getHeight() - rect.bottom;                     }                     //deltaY-=50;                 }                 if (horizontal) {                     int screenWidth = dmwidth;                     if (width < screenWidth) {                         deltaX = (screenWidth - width) / 2 - rect.left;                     } else if (rect.left > 0) {                         deltaX = -rect.left;                     } else if (rect.right < screenWidth) {                         deltaX = screenWidth - rect.right;                     }                 }                 matrix.postTranslate(deltaX, deltaY);             }          public void center() {                 center(true, true);             }          private float spacing(MotionEvent event) {                 float x = event.getX(0) - event.getX(1);                 float y = event.getY(0) - event.getY(1);                 return FloatMath.sqrt(x * x + y * y);             }             /** * 两点的中点 */             private void midPoint(PointF point, MotionEvent event) {                 float x = event.getX(0) + event.getX(1);                 float y = event.getY(0) + event.getY(1);                 point.set(x / 2, y / 2);             }     } }