matrix.postScale(scale,scale,縮放中心,縮放中心); image.setImageMatrix(matrix);

package com.test.administrator.imageviewscale;import android.content.Context;import android.graphics.Matrix;import android.graphics.PointF;import android.renderscript.Float2;import android.renderscript.Float4;import android.util.AttributeSet;import android.util.FloatMath;import android.view.MotionEvent;import android.widget.ImageView;/** * Created by Administrator on 2016/3/21. */public class MyImageView extends ImageView {private PointF centerPoint;private float firstdistance;private Matrix matrix;public MyImageView(Context context) {super(context);initParams();}private void initParams() {matrix = new Matrix();setImageMatrix(matrix);}public MyImageView(Context context, AttributeSet attrs) {super(context, attrs);initParams();}public MyImageView(Context context, AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);initParams();}@Overridepublic boolean onTouchEvent(MotionEvent event) {int count = event.getPointerCount();if(count == 1){switch (event.getAction()){case MotionEvent.ACTION_DOWN:System.out.println("actiondown 1----");break;case MotionEvent.ACTION_MOVE:System.out.println("actionmove 1----");break;case MotionEvent.ACTION_UP:System.out.println("actionup 1----");break;default:break;}}else if(count == 2){switch (event.getAction()&MotionEvent.ACTION_MASK){case MotionEvent.ACTION_POINTER_DOWN: firstdistance = getDistance(event);centerPoint = getCenterPoint(event);System.out.println("actiondown 2===");break;case MotionEvent.ACTION_MOVE:float distance = getDistance(event);float scale = distance / firstdistance;matrix.postScale(scale,scale,centerPoint.x,centerPoint.y);setImageMatrix(matrix);System.out.println(scale + "====");firstdistance = distance;System.out.println("actionmove 2===");break;case MotionEvent.ACTION_UP:break;default:break;}}return true;}/** * 獲取兩個點的中心點坐標 * @param event */private PointF getCenterPoint(MotionEvent event) {PointF point = new PointF();point.x = (event.getX()+event.getX(1))/2;point.y = (event.getY()+event.getY(1))/2;return point;}/** * 兩根手指時手指間的距離 * @param event */private float getDistance(MotionEvent event) {float x1 = event.getX();float y1 = event.getY();float x2 = event.getX(1);float y2 = event.getY(1);float distance = (float) Math.sqrt((x1 - x2)*(x1 - x2)+(y1 - y2)*(y1- y2));return distance;}}

<com.test.administrator.imageviewscale.MyImageViewandroid:id="@+id/iv"android:layout_width="match_parent"android:layout_height="match_parent"android:focusable="true"android:clickable="true"android:scaleType="matrix"  android:src="@drawable/qq" />