最近项目中需要用到手势放大与缩小图片，类似于云相册的功能，还需要图片的单击
网上查找了一个ZoomImageView，可以实现图片放大缩小以及双击放大等操作，但是没有单击效果。而且经查看该类的代码，发现使用到的手势识别
ScaleGestureDetector 会将点击事件拦截
ZoomImageView的代码如下：
package ; import android.annotation.SuppressLint; import android.content.Context; import android.graphics.Matrix; import android.graphics.RectF; import android.graphics.drawable.Drawable; import android.util.AttributeSet; import android.util.Log; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.ScaleGestureDetector; import android.view.GestureDetector.SimpleOnGestureListener; import android.view.ScaleGestureDetector.OnScaleGestureListener; import android.view.View; import android.view.View.OnTouchListener; import android.view.ViewTreeObserver; import android.widget.ImageView; /** * Created by 平sir on 2017/11/8/008. * desc：具有手势识别功能的自定义ImageView */ public class ZoomImageView extends ImageView implements OnScaleGestureListener, OnTouchListener, ViewTreeObserver.OnGlobalLayoutListener {private static final String TAG = ZoomImageView.class.getSimpleName(); public static final float SCALE_MAX = 4.0f; private static final float SCALE_MID = 2.0f; /** * 初始化时的缩放比例，如果图片宽或高大于屏幕，此值将小于0 */ private float initScale = 1.0f; private boolean once = true; /** * 用于存放矩阵的9个值 */ private final float[] matrixValues = new float[9]; /** * 缩放的手势检测 */ private ScaleGestureDetector mScaleGestureDetector = null; private final Matrix mScaleMatrix = new Matrix(); /** * 用于双击检测 */ private GestureDetector mGestureDetector; private OnZoomImageViewSingleClickListener listener; /** * @date:2017/11/16/016 * @author:平sir * @desc: 初始化拦截单击事件的接口对象 */ public void setListener(OnZoomImageViewSingleClickListener listener) {this.listener = listener; }public OnZoomImageViewSingleClickListener getListener() {return listener; }private boolean isAutoScale; private int mTouchSlop; private float mLastX; private float mLastY; private boolean isCanDrag; private int lastPointerCount; private boolean isCheckTopAndBottom = true; private boolean isCheckLeftAndRight = true; public ZoomImageView(Context context) {this(context, null); }public ZoomImageView(Context context, AttributeSet attrs) {super(context, attrs); super.setScaleType(ScaleType.MATRIX); mGestureDetector = new GestureDetector(context, new SimpleOnGestureListener() {@Override public boolean onDoubleTap(MotionEvent e) {if (isAutoScale == true)return true; float x = e.getX(); float y = e.getY(); if (getScale() < SCALE_MID) {ZoomImageView.this.postDelayed(new AutoScaleRunnable(SCALE_MID, x, y), 16); isAutoScale = true; } else if (getScale() >= SCALE_MID && getScale() < SCALE_MAX) {ZoomImageView.this.postDelayed(new AutoScaleRunnable(SCALE_MAX, x, y), 16); isAutoScale = true; } else {ZoomImageView.this.postDelayed(new AutoScaleRunnable(initScale, x, y), 16); isAutoScale = true; }return true; }}); mScaleGestureDetector = new ScaleGestureDetector(context, this); this.setOnTouchListener(this); }/** * 自动缩放的任务 * * @author zhy */ private class AutoScaleRunnable implements Runnable {static final float BIGGER = 1.07f; static final float SMALLER = 0.93f; private float mTargetScale; private float tmpScale; /** * 缩放的中心 */ private float x; private float y; /** * 传入目标缩放值，根据目标值与当前值，判断应该放大还是缩小 * * @param targetScale */ public AutoScaleRunnable(float targetScale, float x, float y) {this.mTargetScale = targetScale; this.x = x; this.y = y; if (getScale() < mTargetScale) {tmpScale = BIGGER; } else {tmpScale = SMALLER; }}@Override public void run() {// 进行缩放 mScaleMatrix.postScale(tmpScale, tmpScale, x, y); checkBorderAndCenterWhenScale(); setImageMatrix(mScaleMatrix); final float currentScale = getScale(); // 如果值在合法范围内，继续缩放 if (((tmpScale > 1f) && (currentScale < mTargetScale))|| ((tmpScale < 1f) && (mTargetScale < currentScale))) {ZoomImageView.this.postDelayed(this, 16); } else // 设置为目标的缩放比例 {final float deltaScale = mTargetScale / currentScale; mScaleMatrix.postScale(deltaScale, deltaScale, x, y); checkBorderAndCenterWhenScale(); setImageMatrix(mScaleMatrix); isAutoScale = false; }}}@SuppressLint("NewApi")@Override public boolean onScale(ScaleGestureDetector detector) {float scale = getScale(); float scaleFactor = detector.getScaleFactor(); if (getDrawable() == null)return true; /** * 缩放的范围控制 */ if ((scale < SCALE_MAX && scaleFactor > 1.0f)|| (scale > initScale && scaleFactor < 1.0f)) {/** * 最大值最小值判断 */ if (scaleFactor * scale < initScale) {scaleFactor = initScale / scale; }if (scaleFactor * scale > SCALE_MAX) {scaleFactor = SCALE_MAX / scale; }/** * 设置缩放比例 */ mScaleMatrix.postScale(scaleFactor, scaleFactor, detector.getFocusX(), detector.getFocusY()); checkBorderAndCenterWhenScale(); setImageMatrix(mScaleMatrix); }return true; }/** * 在缩放时，进行图片显示范围的控制 */ private void checkBorderAndCenterWhenScale() {RectF rect = getMatrixRectF(); float deltaX = 0; float deltaY = 0; int width = getWidth(); int height = getHeight(); // 如果宽或高大于屏幕，则控制范围 if (rect.width() >= width) {if (rect.left > 0) {deltaX = -rect.left; }if (rect.right < width) {deltaX = width - rect.right; }}if (rect.height() >= height) {if (rect.top > 0) {deltaY = -rect.top; }if (rect.bottom < height) {deltaY = height - rect.bottom; }}// 如果宽或高小于屏幕，则让其居中 if (rect.width() < width) {deltaX = width * 0.5f - rect.right + 0.5f * rect.width(); }if (rect.height() < height) {deltaY = height * 0.5f - rect.bottom + 0.5f * rect.height(); }Log.e(TAG, "deltaX = " + deltaX + " , deltaY = " + deltaY); mScaleMatrix.postTranslate(deltaX, deltaY); }/** * 根据当前图片的Matrix获得图片的范围 * * @return */ private RectF getMatrixRectF() {Matrix matrix = mScaleMatrix; RectF rect = new RectF(); Drawable d = getDrawable(); if (null != d) {rect.set(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight()); matrix.mapRect(rect); }return rect; }@Override public boolean onScaleBegin(ScaleGestureDetector detector) {return true; }@Override public void onScaleEnd(ScaleGestureDetector detector) {}@Override public boolean onTouch(View v, MotionEvent event) {/** * 设置拦截单击事件 */ mGestureDetector.setOnDoubleTapListener(new GestureDetector.OnDoubleTapListener() {@Override public boolean onSingleTapConfirmed(MotionEvent motionEvent) {if (listener != null)listener.onClick(); return false; }@Override public boolean onDoubleTap(MotionEvent motionEvent) {return false; }@Override public boolean onDoubleTapEvent(MotionEvent motionEvent) {return false; }}); if (mGestureDetector.onTouchEvent(event))return true; mScaleGestureDetector.onTouchEvent(event); float x = 0, y = 0; // 拿到触摸点的个数 final int pointerCount = event.getPointerCount(); // 得到多个触摸点的x与y均值 for (int i = 0; i < pointerCount; i++) {x += event.getX(i); y += event.getY(i); }x = x / pointerCount; y = y / pointerCount; /** * 每当触摸点发生变化时，重置mLasX , mLastY */ if (pointerCount != lastPointerCount) {isCanDrag = false; mLastX = x; mLastY = y; }lastPointerCount = pointerCount; RectF rectF = getMatrixRectF(); switch (event.getAction()) {case MotionEvent.ACTION_DOWN:if (rectF.width() > getWidth() || rectF.height() > getHeight()) {getParent().requestDisallowInterceptTouchEvent(true); }break; case MotionEvent.ACTION_MOVE:if (rectF.width() > getWidth() || rectF.height() > getHeight()) {getParent().requestDisallowInterceptTouchEvent(true); }Log.e(TAG, "ACTION_MOVE"); float dx = x - mLastX; float dy = y - mLastY; if (!isCanDrag) {isCanDrag = isCanDrag(dx, dy); }if (isCanDrag) {if (getDrawable() != null) {// if (getMatrixRectF().left == 0 && dx > 0) // { // getParent().requestDisallowInterceptTouchEvent(false); // } // // if (getMatrixRectF().right == getWidth() && dx < 0) // { // getParent().requestDisallowInterceptTouchEvent(false); // } isCheckLeftAndRight = isCheckTopAndBottom = true; // 如果宽度小于屏幕宽度，则禁止左右移动 if (rectF.width() < getWidth()) {dx = 0; isCheckLeftAndRight = false; }// 如果高度小雨屏幕高度，则禁止上下移动 if (rectF.height() < getHeight()) {dy = 0; isCheckTopAndBottom = false; }mScaleMatrix.postTranslate(dx, dy); checkMatrixBounds(); setImageMatrix(mScaleMatrix); }}mLastX = x; mLastY = y; break; case MotionEvent.ACTION_UP:case MotionEvent.ACTION_CANCEL:lastPointerCount = 0; break; }return true; }/** * @date:2017/11/16/016 * @author:平sir * @desc: 定义接口，用于拦截单击事件 */ public interface OnZoomImageViewSingleClickListener {void onClick(); }/** * 获得当前的缩放比例 * * @return */ public final float getScale() {mScaleMatrix.getValues(matrixValues); return matrixValues[Matrix.MSCALE_X]; }@Override protected void onAttachedToWindow() {super.onAttachedToWindow(); getViewTreeObserver().addOnGlobalLayoutListener(this); }@SuppressWarnings("deprecation")@Override protected void onDetachedFromWindow() {super.onDetachedFromWindow(); getViewTreeObserver().removeGlobalOnLayoutListener(this); }@Override public void onGlobalLayout() {if (once) {Drawable d = getDrawable(); if (d == null)return; Log.e(TAG, d.getIntrinsicWidth() + " , " + d.getIntrinsicHeight()); int width = getWidth(); int height = getHeight(); // 拿到图片的宽和高 int dw = d.getIntrinsicWidth(); int dh = d.getIntrinsicHeight(); float scale = 1.0f; // 如果图片的宽或者高大于屏幕，则缩放至屏幕的宽或者高 if (dw > width && dh <= height) {scale = width * 1.0f / dw; }if (dh > height && dw <= width) {scale = height * 1.0f / dh; }// 如果宽和高都大于屏幕，则让其按按比例适应屏幕大小 if (dw > width && dh > height) {scale = Math.min(width * 1.0f / dw, height * 1.0f / dh); }initScale = scale; Log.e(TAG, "initScale = " + initScale); mScaleMatrix.postTranslate((width - dw) / 2, (height - dh) / 2); mScaleMatrix.postScale(scale, scale, getWidth() / 2, getHeight() / 2); // 图片移动至屏幕中心 setImageMatrix(mScaleMatrix); once = false; }}/** * 移动时，进行边界判断，主要判断宽或高大于屏幕的 */ private void checkMatrixBounds() {RectF rect = getMatrixRectF(); float deltaX = 0, deltaY = 0; final float viewWidth = getWidth(); final float viewHeight = getHeight(); // 判断移动或缩放后，图片显示是否超出屏幕边界 if (rect.top > 0 && isCheckTopAndBottom) {deltaY = -rect.top; }if (rect.bottom < viewHeight && isCheckTopAndBottom) {deltaY = viewHeight - rect.bottom; }if (rect.left > 0 && isCheckLeftAndRight) {deltaX = -rect.left; }if (rect.right < viewWidth && isCheckLeftAndRight) {deltaX = viewWidth - rect.right; }mScaleMatrix.postTranslate(deltaX, deltaY); }/** * 是否是推动行为 * * @param dx * @param dy * @return */ private boolean isCanDrag(float dx, float dy) {return Math.sqrt((dx * dx) + (dy * dy)) >= mTouchSlop; }}
接下来在代码中初始化该view，并设置点击事件即可
@Override public void UpdateUI(Context context, int position, AlbumDetailBean data) {imageView = (ZoomImageView) view.findViewById(R.id.img); tvDesc = (TextView) view.findViewById(R.id.tv_desc); tvDesc.setText(String.format("来源：%s", data.description)); ImageUtils.loadImage(imageView, data.saveUrl); imageView.setListener(new ZoomImageView.OnZoomImageViewSingleClickListener() {@Override public void onClick() {//点击事件 }}); }
在这里，我项目中用ConvenientBanner实现了轮播，轮播图的imageview为ZoomImageView，测试中发现ZoomImageView会将轮播banner的点击事件进行拦截消费，
这里引入了事件的分发机制
dispatchTouchEvent会向下分发，ActionDown继续向下分发，然后子view如果消费掉事件的话，父view的actionUp不会有响应
原ZoomImageView的代码链接找不到了，这是我拷贝的自己项目中的代码
项目运行的效果图不会上传，就这样吧