Question

我正在开发一个项目，我想通过按钮点击并在我的应用程序中显示来从服务器获取图像。请与我分享这个场景的代码。请帮帮我。

Answer 1

以这种方式创建缓存机制：

    /**
     * Image caching used by volley image loader
     * Created by tasneem on 23/7/15.
     */

    import android.graphics.Bitmap;
    import android.support.v4.util.LruCache;

    import com.android.volley.toolbox.ImageLoader.ImageCache;

    public class LruBitmapCache extends LruCache<String, Bitmap> implements
            ImageCache {
        public static int getDefaultLruCacheSize() {
            final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
            final int cacheSize = maxMemory / 8;

            return cacheSize;
        }

        public LruBitmapCache() {
            this(getDefaultLruCacheSize());
        }

        public LruBitmapCache(int sizeInKiloBytes) {
            super(sizeInKiloBytes);
        }

        @Override
        protected int sizeOf(String key, Bitmap value) {
            return value.getRowBytes() * value.getHeight() / 1024;
        }

        @Override
        public Bitmap getBitmap(String url) {
            return get(url);
        }

        @Override
        public void putBitmap(String url, Bitmap bitmap) {
            put(url, bitmap);
        }
    }

然后以这种方式加入你的VolleyControler：

import android.app.Application;
import android.text.TextUtils;
import android.util.Log;

import com.android.volley.DefaultRetryPolicy;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.Volley;
import com.zingoy.app.ZingoyApplication;

    /**
     * Class for handling all network requests
     * @author tasneem
     */
    public class VolleyController extends Application {

    public static final String TAG = VolleyController.class.getSimpleName();

    private static VolleyController mInstance;
    private RequestQueue mRequestQueue;
    private ImageLoader mImageLoader;

    private VolleyController() {
        mRequestQueue = mRequestQueue != null ? mRequestQueue : Volley.newRequestQueue(ZingoyApplication.getAppContext());
        mImageLoader = new ImageLoader(mRequestQueue, new LruBitmapCache());
    }

    public static synchronized VolleyController getInstance() {
        mInstance = mInstance != null ? mInstance : new VolleyController();
        return mInstance;
    }

    public RequestQueue getRequestQueue() {
        Log.d(TAG, "Cancelling request");
        return mRequestQueue != null ? mRequestQueue :  Volley.newRequestQueue(getApplicationContext());
    }

    public ImageLoader getImageLoader() {
        return mImageLoader != null ? mImageLoader : new ImageLoader(mRequestQueue, new LruBitmapCache());
    }  
}

无论何时想要渲染图像，都可以使用：

    imageLayout.setImageUrl(url, VolleyController.getInstance().getImageLoader());

在android中通过volley从服务器获取图像

1 个答案: