Android通过ImageView设置手指滑动控件缩放

ImageView设置手指滑动缩放效果，具体实现步骤大家通过本文学习下吧！

实现步骤

1, imageview设置scaletype为 android:scaleType=”matrix”

2, 设置imageview的setOnTouchListener,重写里面的代码

3, 新建一个matrix,

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

这样image的大小就会改变了.

需要注意的几点是 imageview一定要设置scaletype为matrix,否则图片不能进行缩放.而且Bitmap也可以通过Matrix改变大小.

也可以用自定义控件imageview,重写里面的onTouchEvent,本文就是用的自定义控件得到方式实现的.

代码

自定义控件的代码,主要是重写的onTouchEvent的代码

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;}/** * 获取两个点的中心点坐标 * @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;}/** * 两根手指时手指间的距离 * @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;}}

imageview的代码

总结

以上所述是小编给大家介绍的Android通过ImageView设置手指滑动控件缩放，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对脚本之家网站的支持！

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