allprojects {
    repositories {
        ...
        maven { url "https://jitpack.io" }
    }
}

compile 'com.github.open-android:Picasso:0.1.0'

   Picasso.with(context) //设置context
    .load(url) //图片url地址
    .placeholder(R.drawable.placeholder) //加载时显示的图片
    .error(R.drawable.error) //加载错误显示的图片
    .fit() //自动按照图片尺寸进行压缩
    .tag("image") //图片tag，便于控制图片加载和暂停加载
    .into(view);//图片显示的imageview

  我们在列表或者是gradview中显示图片时，滑动列表时可以暂停加载图片，等滑动结束后再加载
  listView.setOnScrollListener(new AbsListView.OnScrollListener() {
        @Override
        public void onScrollStateChanged(AbsListView view, int scrollState) {
            final Picasso picasso = Picasso.with(SampleGridViewActivity.this);
            if (scrollState == SCROLL_STATE_IDLE || scrollState == SCROLL_STATE_TOUCH_SCROLL) {
                picasso.resumeTag("image");//开始加载所有tag为image的imageview
            } else {
                picasso.pauseTag("image");//开始加载所有tag为image的imageview
            }
        }

<uses-permission android:name="android.permission.INTERNET" />