Android利用Volley异步加载数据(JSON和图片)完整示例

jopen 11年前

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;            @Override            protected 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>() {                            @Override                            public void onResponse(JSONObject response) {                                System.out.println("response="+response);                                if (progressDialog.isShowing()&&progressDialog!=null) {                                    progressDialog.dismiss();                                }                            }                        },                         new Response.ErrorListener() {                            @Override                            public 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() {                    @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://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() {                    @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);            }                }  
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>