vollery异步加载图片

来源：互联网发布：js将div disabled属性编辑：程序博客网时间：2024/05/16 01:17

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 extendsActivity {  
    privateImageView mImageView;  
    privateNetworkImageView mNetworkImageView;  
    @Override
    protectedvoid onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.main);  
        init();  
    } 
      
    privatevoid init(){  
        mImageView=(ImageView) findViewById(R.id.imageView);  
        mNetworkImageView=(NetworkImageView)findViewById(R.id.networkImageView); 
        getJSONByVolley();  
        loadImageByVolley();  
        showImageByNetworkImageView();  
    } 
  
    /**
     * 利用Volley获取JSON数据
     */
    privatevoid 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 = newJsonObjectRequest(  
               Request.Method.GET,   
               JSONDataUrl,   
               null,  
               new Response.Listener<JSONObject>() { 
                   @Override 
                   public voidonResponse(JSONObject response) {  
                       System.out.println("response="+response); 
                       if (progressDialog.isShowing()&&progressDialog!=null) { 
                           progressDialog.dismiss();  
                       }  
                   }  
               },   
               new Response.ErrorListener() { 
                   @Override 
                   public voidonErrorResponse(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
     */
    privatevoid 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 = newImageCache() {  
            @Override 
            public void putBitmap(String key, Bitmap value) {  
               lruCache.put(key, value);  
            }  
  
            @Override 
            public Bitmap getBitmap(String key) { 
               return lruCache.get(key); 
            }  
        };  
        ImageLoader imageLoader = newImageLoader(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
     */
    privatevoid 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 = newImageCache() {  
            @Override 
            public void putBitmap(String key, Bitmap value) {  
               lruCache.put(key, value);  
            }  
  
            @Override 
            public Bitmap getBitmap(String key) { 
               return lruCache.get(key); 
            }  
        };  
        ImageLoader imageLoader = newImageLoader(requestQueue, imageCache);  
        mNetworkImageView.setTag("url"); 
        mNetworkImageView.setImageUrl(imageUrl,imageLoader);  
    } 
  
}

main.xml如下:

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<RelativeLayoutxmlns: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>

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