项目地址：https://github.com/chrisbanes/PhotoView
用开源项目有个好处，一是实现简单，二是bug少。那么我们就来说下这个项目能够实现的效果：
1.单个图片的双指缩放，双击放大缩小
PhotoViewAttacher mAttacher;
ImageView mImageView; @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Any implementation of ImageView can be used!
mImageView = (ImageView) findViewById(R.id.iv_photo); // Set the Drawable displayed
Drawable bitmap = getResources().getDrawable(R.drawable.ic_launcher);
mImageView.setImageDrawable(bitmap); // Attach a PhotoViewAttacher, which takes care of all of the zooming
// functionality.
mAttacher = new PhotoViewAttacher(mImageView);
2.图片的旋转效果，可以精准指定旋转的度数
private PhotoView photo;
private final Handler handler = new Handler();
private boolean rotating = false; @Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
photo = new PhotoView(this);
photo.setImageResource(R.drawable.wallpaper);
setContentView(photo); photo.setRotationBy(10);
}
3.放入viewpager来做照片浏览，浏览中可以放大和缩小（这里的viewpager可以设置是否允许左右滑动，如果不用这功能，就直接用普通的viewpager）
private static final String ISLOCKED_ARG = "isLocked";
private ViewPager mViewPager;
private MenuItem menuLockItem;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view_pager);
mViewPager = (HackyViewPager) findViewById(R.id.view_pager);
setContentView(mViewPager);
mViewPager.setAdapter(new SamplePagerAdapter());
if (savedInstanceState != null) {
boolean isLocked = savedInstanceState.getBoolean(ISLOCKED_ARG, false);
((HackyViewPager) mViewPager).setLocked(isLocked);
}
}
static class SamplePagerAdapter extends PagerAdapter {
private static final int[] sDrawables = { R.drawable.wallpaper, R.drawable.wallpaper, R.drawable.wallpaper,
R.drawable.wallpaper, R.drawable.wallpaper, R.drawable.wallpaper };
@Override
public int getCount() {
return sDrawables.length;
}
@Override
public View instantiateItem(ViewGroup container, int position) {
//定义可以缩放的图片对象
PhotoView photoView = new PhotoView(container.getContext());
photoView.setImageResource(sDrawables[position]);
// Now just add PhotoView to ViewPager and return it
container.addView(photoView, LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
return photoView;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
}
这是官方文档的例子
ImageView mImageView;
PhotoViewAttacher mAttacher; @Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main); // Any implementation of ImageView can be used!
mImageView = (ImageView) findViewById(R.id.iv_photo); // Set the Drawable displayed
Drawable bitmap = getResources().getDrawable(R.drawable.wallpaper);
mImageView.setImageDrawable(bitmap); // Attach a PhotoViewAttacher, which takes care of all of the zooming functionality.
mAttacher = new PhotoViewAttacher(mImageView);
} // If you later call mImageView.setImageDrawable/setImageBitmap/setImageResource/etc then you just need to call
attacher.update();
下面给出的源码是我修改过的，我把原来的放大两次变成了放大一次，然后再双击的话就缩小到原图。至于单击直接退出的效果我给出一个思路，点击一个缩略图后开启一个activity，用渐变的效果显示。在这个弹出的activity放一个可以缩放的图片，然后给这个图片加个监听器（源码中我已经加了），点击后这个activity渐变消失。很简单吧~ 不过这里面需要注意的是缩略图的设置还有弹出activity时很可能要用进度条来等待网络图片