volley 应用 GET POST请求 图片异步加载



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

package com.example.volleydemo;import java.util.HashMap;import java.util.Map;import org.json.JSONObject;import android.app.Activity;import android.app.ProgressDialog;import android.graphics.Bitmap;import android.os.Bundle;import android.support.v4.util.LruCache;import android.util.Log;import android.widget.ImageView;import com.android.volley.Request;import com.android.volley.RequestQueue;import com.android.volley.Response;import com.android.volley.VolleyError;import com.android.volley.toolbox.ImageLoader;import com.android.volley.toolbox.ImageLoader.ImageCache;import com.android.volley.toolbox.ImageLoader.ImageListener;import com.android.volley.toolbox.JsonObjectRequest;import com.android.volley.toolbox.NetworkImageView;import com.android.volley.toolbox.StringRequest;import com.android.volley.toolbox.Volley;/** * Demo描述: 1 利用Volley获取JSON数据  2 利用Volley异步加载图片 1 利用NetworkImageView加载网路图片 *  */public class MainActivity extends Activity {    private ImageView mImageView;    private NetworkImageView mNetworkImageView;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        init();    }    private void init() {        mImageView = (ImageView) findViewById(R.id.imageView);        mNetworkImageView = (NetworkImageView) findViewById(R.id.networkImageView);        getJSONByVolley();        getJsonPost();        loadImageByVolley();        showImageByNetworkImageView();    }    /**     * 利用Volley获取JSON数据     */    private void getJSONByVolley() {        RequestQueue requestQueue = Volley.newRequestQueue(this);        String JSONDataUrl = "http://127.0.0.1:8099/api/api.ashx?action=product_list&ver=1&pageindex=1&pageCount=5";        final ProgressDialog progressDialog = ProgressDialog.show(this,                "请稍后...", "正在加载...");        JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(                Request.Method.GET, JSONDataUrl, null,                new Response.Listener<JSONObject>() {                    @Override                    public void onResponse(JSONObject response) {                        //处理返回的JSON数据                        Log.e("bbb", response.toString());                        if(progressDialog.isShowing() && progressDialog!=null){                           progressDialog.dismiss(); }                    }                }, new Response.ErrorListener() {                    @Override                    public void onErrorResponse(VolleyError arg0) {                        // System.out.println("sorry,Error");                        Log.e("aaa", arg0.toString());                    }                });        requestQueue.add(jsonObjectRequest);    }    /***     * 以POST形式加载数据     */    private void getJsonPost() {        RequestQueue requestQueue = Volley.newRequestQueue(this);        String url = "http://127.0.0.1:8099/api/api.ashx";        StringRequest postRequest = new StringRequest(Request.Method.POST, url,                new Response.Listener<String>() {                    @Override                    public void onResponse(String response) {                        //处理返回的JSON数据                        Log.d("Response", response);                    }                }, new Response.ErrorListener() {                    @Override                    public void onErrorResponse(VolleyError error) {                        // error                    }                }) {            @Override            protected Map<String, String> getParams() {                //POST 参数                Map<String, String> params = new HashMap<String, String>();                params.put("action", "product_list");                params.put("ver", "1");                params.put("pageindex", "1");                params.put("pageCount", "5");                return params;            }        };        requestQueue.add(postRequest);    }    /**     * 利用Volley异步加载图片     *      * 注意方法参数: getImageListener(ImageView view, int defaultImageResId, int     * errorImageResId) 第一个参数:显示图片的ImageView 第二个参数:默认显示的图片资源 第三个参数:加载错误时显示的图片资源     */    private void loadImageByVolley() {        String imageUrl = "http://d.hiphotos.baidu.com/pic/w%3D310/sign=a00aca825aafa40f3cc6c8dc9b65038c/060828381f30e9246b63e1814c086e061c95f7bf.jpg";        RequestQueue requestQueue = Volley.newRequestQueue(this);        final LruCache<String, Bitmap> lruCache = new LruCache<String, Bitmap>(                20);        ImageCache imageCache = new ImageCache() {            @Override            public void putBitmap(String key, Bitmap value) {                lruCache.put(key, value);            }            @Override            public Bitmap getBitmap(String key) {                return lruCache.get(key);            }        };        ImageLoader imageLoader = new ImageLoader(requestQueue, imageCache);        ImageListener listener = ImageLoader.getImageListener(mImageView,                R.drawable.ic_launcher, R.drawable.ic_launcher);        imageLoader.get(imageUrl, listener);    }    /**     * 利用NetworkImageView显示网络图片     */    private void showImageByNetworkImageView() {        String imageUrl = "http://d.hiphotos.baidu.com/pic/w%3D310/sign=a00aca825aafa40f3cc6c8dc9b65038c/060828381f30e9246b63e1814c086e061c95f7bf.jpg";        RequestQueue requestQueue = Volley.newRequestQueue(this);        final LruCache<String, Bitmap> lruCache = new LruCache<String, Bitmap>(                20);        ImageCache imageCache = new ImageCache() {            @Override            public void putBitmap(String key, Bitmap value) {                lruCache.put(key, value);            }            @Override            public Bitmap getBitmap(String key) {                return lruCache.get(key);            }        };        ImageLoader imageLoader = new ImageLoader(requestQueue, imageCache);        mNetworkImageView.setTag("url");        mNetworkImageView.setImageUrl(imageUrl, imageLoader);    }}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"      xmlns:tools="http://schemas.android.com/tools"      android:layout_width="match_parent"      android:layout_height="match_parent"       >        <com.android.volley.toolbox.NetworkImageView          android:id="@+id/networkImageView"          android:layout_width="fill_parent"          android:layout_height="wrap_content"          android:layout_centerHorizontal="true"          android:layout_marginTop="30dip"      />             <ImageView          android:id="@+id/imageView"          android:layout_width="fill_parent"          android:layout_height="wrap_content"          android:layout_centerInParent="true"      />    </RelativeLayout>

引入Volley非常简单，首先，从git库先克隆一个下来：

git clone https://android.googlesource.com/platform/frameworks/volley 

转自：http://www.cnblogs.com/freexiaoyu/p/3446028.html