Android利用Volley异步加载数据(JSON和图片)完整示例
MainActivity如下:
package cc.testvolley;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.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.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 * * 参考资料: * 1 http://blog.csdn.net/t12x3456/article/details/9221611 * 2 http://blog.csdn.net/xyz_lmn/article/details/12063561 * 3 http://blog.csdn.net/lfdfhl/article/details/12221875 * Thank you very much */public class MainActivity extends Activity { private ImageView mImageView; private NetworkImageView mNetworkImageView;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);init();}private void init(){mImageView=(ImageView) findViewById(R.id.imageView);mNetworkImageView=(NetworkImageView)findViewById(R.id.networkImageView);getJSONByVolley();loadImageByVolley();showImageByNetworkImageView();}/** * 利用Volley获取JSON数据 */private void getJSONByVolley() {RequestQueue requestQueue = Volley.newRequestQueue(this);String JSONDataUrl = "http://pipes.yahooapis.com/pipes/pipe.run?_id=giWz8Vc33BG6rQEQo_NLYQ&_render=json";final ProgressDialog progressDialog = ProgressDialog.show(this, "This is title", "...Loading...");JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, JSONDataUrl, null,new Response.Listener<JSONObject>() {@Overridepublic void onResponse(JSONObject response) {System.out.println("response="+response);if (progressDialog.isShowing()&&progressDialog!=null) {progressDialog.dismiss();}}}, new Response.ErrorListener() {@Overridepublic void onErrorResponse(VolleyError arg0) { System.out.println("sorry,Error");}});requestQueue.add(jsonObjectRequest);}/** * 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://avatar.csdn.net/6/6/D/1_lfdfhl.jpg";RequestQueue requestQueue = Volley.newRequestQueue(this);final LruCache<String, Bitmap> lruCache = new LruCache<String, Bitmap>(20);ImageCache imageCache = new ImageCache() {@Overridepublic void putBitmap(String key, Bitmap value) {lruCache.put(key, value);}@Overridepublic 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://avatar.csdn.net/6/6/D/1_lfdfhl.jpg";RequestQueue requestQueue = Volley.newRequestQueue(this);final LruCache<String, Bitmap> lruCache = new LruCache<String, Bitmap>(20);ImageCache imageCache = new ImageCache() {@Overridepublic void putBitmap(String key, Bitmap value) {lruCache.put(key, value);}@Overridepublic Bitmap getBitmap(String key) {return lruCache.get(key);}};ImageLoader imageLoader = new ImageLoader(requestQueue, imageCache);mNetworkImageView.setTag("url");mNetworkImageView.setImageUrl(imageUrl,imageLoader);}}
main.xml如下:
<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="120dip" android:layout_height="120dip" android:layout_centerHorizontal="true" android:layout_marginTop="30dip" /> <ImageView android:id="@+id/imageView" android:layout_width="120dip" android:layout_height="120dip" android:layout_centerInParent="true" /></RelativeLayout>
PS：
请务必导入Volley.jar