Volley使用指南

1.什么是Volley

在这之前，我们在程序中需要和网络通信的时候，大体使用的东西莫过于AsyncTaskLoader，HttpURLConnection，AsyncTask，HTTPClient（Apache）等，今年的Google I/O 2013上，Volley发布了。Volley是Android平台上的网络通信库，能使网络通信更快，更简单，更健壮。

视频：http://www.youtube.com/watch?v=y（需要翻墙）优酷：http://v.youku.com/v_show/id_XNTU4ODgzNjg4.html

Volley提供的功能
简单来说，它提供了如下的便利功能：

Volley automatically schedule all network requests. It means that Volley will be taking care of all the network requests your app executes for fetching response or image from web.
Volley provides transparent disk and memory caching.
Volley provides powerful cancellation request API. It means that you can cancel a single request or you can set blocks or scopes of requests to cancel.
Volley provides powerful customization abilities.
Volley provides Debugging and tracing tools

2.使用Volley

从git库先克隆一个下来：git clone https://android.googlesource.com/platform/frameworks/volley

将volley引入工程即可

http请求

      RequestQueue  mQueue = Volley.newRequestQueue(getApplicationContext());
        String url = "https://api.instagram.com/v1/media/popular?client_id=e8e3eb77fcab4830947fed8677eeb6cd";
      
        JsonObjectRequest jsonRequet = new JsonObjectRequest(Method.GET, url,
                null, new Listener<JSONObject>() {
                    public void onResponse(JSONObject result) {
                       Log.i(TAG, "请求成功"+result);
                       
                    }
                }, new Response.ErrorListener() {
                    public void onErrorResponse(VolleyError error) {
                        Log.e(TAG, "请求失败");
                    }
                });
        jsonRequet.setTag(TAG);
        mQueue.add(jsonRequet);

ImageView设置图片

RequestQueue  mQueue = Volley.newRequestQueue(getApplicationContext());
        imageview = (ImageView) findViewById(R.id.imageview);
        mImageLoader = new ImageLoader(mQueue, new ImageCache() {
            private final LruCache<String, Bitmap> mCache = new LruCache<String, Bitmap>( 10 * 1024 * 1024){
                @Override
                protected int sizeOf(String key, Bitmap value) {
                    return value.getRowBytes() * value.getHeight();
                }
            };
            public void putBitmap(String url, Bitmap bitmap) {
                mCache.put(url, bitmap);
            }
            public Bitmap getBitmap(String url) {
                return mCache.get(url);
            }
        });
        String imageUrl="http://h.hiphotos.baidu.com/pic/w%3D230/sign=cec1af55a044ad342ebf8084e0a30c08/f11f3a292df5e0fec6c784b95d6034a85fdf72ae.jpg";
        ImageListener listener = ImageLoader.getImageListener(imageview, android.R.drawable.ic_menu_rotate, android.R.drawable.ic_delete);  
        mImageLoader.get(imageUrl, listener);

使用NetworkImageView

Volley提供了一个新的控件NetworkImageView来代替传统的ImageView，这个控件的图片属性可以通过setImageUrl方法来设置网络图片

 RequestQueue  mQueue = Volley.newRequestQueue(getApplicationContext());
        imageview = (NetworkImageView) findViewById(R.id.imageview);
        mImageLoader = new ImageLoader(mQueue, new ImageCache() {
            private final LruCache<String, Bitmap> mCache = new LruCache<String, Bitmap>( 10 * 1024 * 1024){
                @Override
                protected int sizeOf(String key, Bitmap value) {
                    return value.getRowBytes() * value.getHeight();
                }
            };
            public void putBitmap(String url, Bitmap bitmap) {
                mCache.put(url, bitmap);
            }
            public Bitmap getBitmap(String url) {
                return mCache.get(url);
            }
        });
        String imageUrl="http://h.hiphotos.baidu.com/pic/w%3D230/sign=cec1af55a044ad342ebf8084e0a30c08/f11f3a292df5e0fec6c784b95d6034a85fdf72ae.jpg";
        
        imageview.setImageUrl(imageUrl, mImageLoader);

定制自己的Request

https://gist.github.com/ficusk/5474673

3.参考

http://blog.csdn.net/t12x3456/article/details/9221611

http://blog.csdn.net/geekpark/article/details/9380933

http://stackoverflow.com/questions/16626032/volley-post-get-parameters

http://stackoverflow.com/questions/17571759/looking-for-a-documentation-for-the-android-volley-api

（文档）http://files.evancharlton.com/volley-docs/