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

 

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