高仿新浪点击图片放大(可以拖动，动态缩小放大，以及再次点击图片消失和保存图片的功能)

有图有真相：

最近在做项目的时候用到了点击图片放大效果，于是就开始实现，本以为挺简单的，实现起来还是遇到不少的小问题啊：

第一：只实现点击图片放大，再次点击消失，这个好实现；

第二：只实现图片可以拖动，而且可以动态缩小放大，这个也好实现；

第三：第一 和第二同步实现就出现问题了：

具体的问题是：

（1）setOnClickListener 和 setOnTouchListener 同时设置的时候，若是setOnTouchListener的返回值为true,则不会再执行setOnClickListener ；若是返回为false,则会执行setOnClickListener 

（2）将setOnTouchListener的返回值设为false之后，运行项目，图片缩小放大之后会直接消失，也就是直接执行了setOnClickListener ，但是项目的要求是，图片移动了或者放大缩小了，依旧显示图片，只有点击的时候才会使图片消失，我于是就用一个变量进行控制手指点击屏幕之后的大小小于1的时候才算是点击了图片，从而让图片消失，具体不多说了，看图和代码：

 

public class ImageToFullScreenActivity extends Activity implementsOnClickListener {private String mImageUrl;private ImageWorker mImageWorker;private int mImageWidth;private int mImageHeight;private ImageView mFullImageView;private LinearLayout mImageLayout;private ImageView mSaveImage;private Boolean isShutDownPic = true;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.image_to_full_screen);mImageUrl = getIntent().getStringExtra("imageUrl");init();}private void init() {mImageLayout = (LinearLayout) findViewById(R.id.image_layout);mFullImageView = (ImageView) findViewById(R.id.full_image);mSaveImage = (ImageView) findViewById(R.id.save_image);mSaveImage.setOnClickListener(this);mImageLayout.setOnClickListener(this);mFullImageView.setOnClickListener(this);mFullImageView.setOnTouchListener(new TouchListener());WindowManager wm = (WindowManager) getSystemService(Context.WINDOW_SERVICE);DisplayMetrics outMetrics = new DisplayMetrics();wm.getDefaultDisplay().getMetrics(outMetrics);mImageWidth = (int) (outMetrics.widthPixels * 1.0d);mImageHeight = mImageWidth;ImageCacheParams cacheParams = new ImageCacheParams();cacheParams.loadingResId = R.drawable.image_full_screen;cacheParams.memCacheSize = ImageCache.DEFAULT_MEM_CACHE_SIZE_BIG;cacheParams.reqWidth = mImageWidth;cacheParams.reqHeight = mImageHeight;mImageWorker = new ImageWorker(this,(HealthApplication) getApplication());mImageWorker.addParams(cacheParams);mImageWorker.loadBitmap(mImageUrl, mFullImageView);LayoutParams params = new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT);mFullImageView.setLayoutParams(params);}@Overridepublic void onClick(View v) {// TODO Auto-generated method stubswitch (v.getId()) {case R.id.save_image:SaveImageToSysAlbum();break;case R.id.image_layout:if(isShutDownPic){ImageToFullScreenActivity.this.finish();}isShutDownPic = true;break;case R.id.full_image:if(isShutDownPic){ImageToFullScreenActivity.this.finish();}isShutDownPic = true;break;default:break;}}/** * 將ImageView中的圖片保存到系统相册 */private void SaveImageToSysAlbum() {if (FileUtil.isSdCardExist()) {BitmapDrawable bmpDrawable = (BitmapDrawable) mFullImageView.getDrawable();Bitmap bmp = bmpDrawable.getBitmap();if (bmp != null) {try {/* * ContentResolver cr = getContentResolver(); String url = * MediaStore.Images.Media.insertImage(cr, bmp, * String.valueOf(System.currentTimeMillis()), ""); */File tempFile = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM).getPath()+ "/"+ String.valueOf(System.currentTimeMillis())+ ".png");if (tempFile.exists()) {tempFile.delete();}try {tempFile.createNewFile();} catch (IOException e) {e.printStackTrace();}FileOutputStream fOut = null;try {fOut = new FileOutputStream(tempFile);} catch (FileNotFoundException e) {e.printStackTrace();}bmp.compress(Bitmap.CompressFormat.PNG, 100, fOut);try {fOut.flush();fOut.close();} catch (IOException e) {// TODO: handle exceptione.printStackTrace();}Toast.makeText(this, getString(R.string.save_succ),Toast.LENGTH_SHORT).show();} catch (Exception e) {e.printStackTrace();}} else {Toast.makeText(this, getString(R.string.no_iamge_save_fail),Toast.LENGTH_SHORT).show();}} else {Toast.makeText(this, getString(R.string.no_sdcard_save_fail),Toast.LENGTH_SHORT).show();}String release = android.os.Build.VERSION.RELEASE;String tempID = release.substring(0, 3);if (Double.parseDouble(tempID) >= 4.4) {// 安卓4.4以上版本的时候使用这个，以下的使用else语句里面的MediaScannerConnection.scanFile(this,new String[] { Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM).getPath()+ "/" }, null, null);} else {sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED,Uri.parse("file://"+ Environment.getExternalStorageDirectory())));MediaScannerConnection.scanFile(this,new String[] { Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM).getPath()+ "/" }, null, null);}}private class TouchListener implements OnTouchListener {private PointF startPoint = new PointF();private Matrix matrix = new Matrix();private Matrix currentMaritx = new Matrix();private int mode = 0; // 用于标记模式private static final int DRAG = 1; // 拖动private static final int ZOOM = 2; // 放大private float startDis = 0;private PointF midPoint; // 中心点@Overridepublic boolean onTouch(View v, MotionEvent event) {switch (event.getAction() & MotionEvent.ACTION_MASK) {case MotionEvent.ACTION_DOWN:mode = DRAG; // 拖拽currentMaritx.set(mFullImageView.getImageMatrix()); // 记录ImageView当前移动位置startPoint.set(event.getX(), event.getY()); // 开始点break;case MotionEvent.ACTION_MOVE:// 移动事件float tempX = event.getX() - startPoint.x;float tempY = event.getY() - startPoint.y;/** * 控制移动小于1.0的情况下，视为没有移动，执行点击事件 */if(Math.abs(tempX) < 1.0 && Math.abs(tempY) < 1.0){isShutDownPic = true;}else {isShutDownPic = false;}mFullImageView.setScaleType(ImageView.ScaleType.MATRIX);if (mode == DRAG) { // 图片拖动事件float dx = event.getX() - startPoint.x; // x轴移动距离float dy = event.getY() - startPoint.y;matrix.set(currentMaritx); // 在当前的位置基础上移动matrix.postTranslate(dx, dy);} else if (mode == ZOOM) { // 图片放大事件float endDis = distance(event); // 结束距离if (endDis > 10f) {float scale = endDis / startDis; // 放大倍数matrix.set(currentMaritx);matrix.postScale(scale, scale, midPoint.x, midPoint.y);}}break;case MotionEvent.ACTION_UP:mode = 0;break;// 有手指离开屏幕，但屏幕还有触点（手指）case MotionEvent.ACTION_POINTER_UP:mode = 0;break;// 当屏幕上已经有触点（手指），再有一个手指压下屏幕case MotionEvent.ACTION_POINTER_DOWN:mode = ZOOM;startDis = distance(event);if (startDis > 10f) { // 避免手指上有两个midPoint = mid(event);currentMaritx.set(mFullImageView.getImageMatrix()); // 记录当前的缩放倍数}break;}// 显示缩放后的图片mFullImageView.setImageMatrix(matrix);return false;}}/** * 计算两点之间的距离 *  * @param event * @return */public static float distance(MotionEvent event) {float dx = event.getX(1) - event.getX(0);float dy = event.getY(1) - event.getY(0);return FloatMath.sqrt(dx * dx + dy * dy);}/** * 计算两点之间的中间点 *  * @param event * @return */public static PointF mid(MotionEvent event) {float midX = (event.getX(1) + event.getX(0)) / 2;float midY = (event.getY(1) + event.getY(0)) / 2;return new PointF(midX, midY);}}

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