Android开源框架——图片加载与缓存库 Picasso

介绍
Picasso是由Square开发的一款图片库，具有强大的下载与缓存功能，可以对图片进行处理。它简化了来自外部图片的处理过程，尤其是远程图片。
开源地址：https://github.com/square/picasso

安装
build.gradle

compile 'com.squareup.picasso:picasso:2.5.2'

图片处理功能
缩放

Picasso.with(this)
 .load("https://img-blog.youkuaiyun.com/20160605162635345")
 .resize(100, 100)
 .into(imageView)

旋转

Picasso.with(this)
    .load("https://img-blog.youkuaiyun.com/20160605162635345")
    .rotate(180)
    .into(imageView);

默认图片

Picasso.with(this)
    .load("https://img-blog.youkuaiyun.com/20160605162635345")
    .placeholder(R.drawable.image_name)
    .into(imageView);

加载失败图片

Picasso.with(this)
    .load("https://img-blog.youkuaiyun.com/20160605162635345")
    .error(R.drawable.image_name)
    .into(imageView);

组合

Picasso.with(this)
    .load("https://img-blog.youkuaiyun.com/20160605162635345")
    .placeholder(R.drawable.image_name_default)
    .error(R.drawable.image_name_error)
    .into(imageView);

Demo

package com.app.client;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ImageView;

import com.squareup.picasso.Picasso;

public class MainActivity extends AppCompatActivity {

    private ImageView imageView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        imageView = (ImageView) findViewById(R.id.imageId);
        Picasso.with(getApplicationContext()).load("https://img-blog.youkuaiyun.com/20160605162635345").into(imageView);
    }
}