安卓：在imageview的

我一直试图在这一GirdView显示从URL图像显示来自URL的图像。某些图像显示正常，但某些图像显示不正确。我还将图像保存在缓存中，以便下次更快地显示图像。这是我的代码。

MainActivity.java

package com.example.gridview; 


public class MainActivity extends Activity { 

ArrayList<String> imageList = new ArrayList<String>(); 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    imageList 
    .add("http://wallpapersus.com/wallpapers/2012/10/Megan-Fox-22-854x960.jpg"); 
    imageList.add("http://www.wallpapersdesign.net 
    /wallpapers/2013/12/Transformers-Megan-Fox-854x960.jpg"); 
    imageList 
      .add("http://wallpapersus.com/wallpapers/2012/10/Megan-Fox1-854x960.jpg"); 
    imageList 
    .add("http://wallpapersus.com/wallpapers/2012/10/Megan-Fox-24-854x960.jpg"); 

    imageList 
    .add("http://topwalls.net/wallpapers/2013/06/Wallpapers-Megan-Fox-11-854x960.jpg"); 
    imageList 
      .add("http://topwalls.net/wallpapers/2013/06/Megan-Fox-133-854x960.jpg"); 


    imageList 
      .add("http://topwalls.net/wallpapers/2013/06/Megan-Fox-89-854x960.jpg"); 

    GridView gridview = (GridView) findViewById(R.id.gridview); 
    gridview.setAdapter(new ImageAdapter(this, imageList)); 
    gridview.setOnItemClickListener(new OnImageClickListener(1)); 
} 

class OnImageClickListener implements OnItemClickListener { 

    public int position; 

    // constructor 
    public OnImageClickListener(int position) { 
     this.position = position; 
    } 

    @Override 
    public void onItemClick(AdapterView<?> v, View arg1, int arg2, long arg3) { 
     Intent i = new Intent(getApplicationContext(), 
       FullScreenViewActivity.class); 
     Bundle basket = new Bundle(); 
     basket.putStringArrayList("url", imageList); 
     basket.putString("position", String.valueOf(arg2)); 
     i.putExtras(basket); 
     i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
     getApplicationContext().startActivity(i); 
     Log.e("Activity ImageClass", "Left from this class"); 
    } 

} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.main, menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    // Handle item selection 
    switch (item.getItemId()) { 
    case R.id.action_settings: 
     refresh(); 
     return true; 

    default: 
     return super.onOptionsItemSelected(item); 
    } 
} 

    private void refresh() { 

     GridView gridview = (GridView) findViewById(R.id.gridview); 
     gridview.setAdapter(new ImageAdapter(this, imageList)); 
     gridview.setOnItemClickListener(new OnImageClickListener(1)); 
    } 
}

这是适配器

package com.example.gridview; 


public class ImageAdapter extends BaseAdapter { 
private Activity mContext; 
ArrayList<String> imageList; 
ImageLoader imageLoader; 
ProgressDialog progress; 
int versionCode = 10; 

public ImageAdapter(Activity c, ArrayList<String> imageList) { 
    mContext = c; 
    this.imageList = imageList; 
    imageLoader = new ImageLoader(mContext, 200); 
} 

@Override 
public int getCount() { 
    return imageList.size(); 
} 

@Override 
public Object getItem(int position) { 
    return null; 
} 

@Override 
public long getItemId(int position) { 
    return 0; 
} 

// create a new ImageView for each item referenced by the Adapter 
@Override 
public View getView(final int position, View convertView, ViewGroup parent) { 
    final ImageView imageView; 
    if (convertView == null) { // if it's not recycled, initialize some 
           // attributes 
     imageView = new ImageView(mContext); 

    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.HONEYCOMB) { 

      Log.e("Inside", "if"); 
      imageView.setLayoutParams(new GridView.LayoutParams(185, 185)); 
      imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); 
      imageView.setPadding(8, 8, 8, 8); 
      imageView.setId(position); 
     } else { 
      Log.e("Inside", "else"); 
      imageView.setLayoutParams(new GridView.LayoutParams(90, 90)); 
      imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); 
      imageView.setPadding(8, 8, 8, 8); 
     } 

    } else { 

     imageView = (ImageView) convertView; 
    } 
    //imageLoader.clearCache(); 
    imageLoader.DisplayImage(imageList.get(position), imageView); 

    return imageView; 
} 
}

ImageLoader.java

package com.example.gridview; 

public class ImageLoader { 

MemoryCache memoryCache = new MemoryCache(); 
FileCache fileCache; 
public int REQUIRED_SIZE; 
private Map<ImageView, String> imageViews = Collections 
     .synchronizedMap(new WeakHashMap<ImageView, String>()); 
ExecutorService executorService; 
Activity context; 

public ImageLoader(Activity context, int size) { 
    fileCache = new FileCache(context, size); 
    this.context = context; 
    executorService = Executors.newFixedThreadPool(20); 
    REQUIRED_SIZE = size; 
} 

final int stub_id = R.drawable.ic_menu_camera; 

public void DisplayImage(String url, ImageView imageView) { 
    imageViews.put(imageView, url); 
    Bitmap bitmap = memoryCache.get(url); 
    if (bitmap != null) 
     imageView.setImageBitmap(bitmap); 
    else { 
     queuePhoto(url, imageView); 
     imageView.setImageResource(stub_id); 
    } 
} 

public void setWallpaper(String url) { 
    Bitmap bitmap = memoryCache.get(url); 
    if (bitmap != null) { 
     WallpaperManager myWallpaperManager = WallpaperManager 
       .getInstance(context); 
     // below line of code will set any image which is in the 
     // drawable 
     // folder 
     // myWallpaperManager.setResource(R.drawable.icon); 
     DisplayMetrics metrics = new DisplayMetrics(); 
     context.getWindowManager().getDefaultDisplay().getMetrics(metrics); 
     int height = metrics.heightPixels; 
     int width = metrics.widthPixels; 
     Bitmap bitmap1 = Bitmap.createScaledBitmap(bitmap, width, height, 
       true); 
     WallpaperManager wallpaperManager = WallpaperManager 
       .getInstance(context); 
     // wallpaperManager.setWallpaperOffsetSteps(1, 1); 
     wallpaperManager.suggestDesiredDimensions(width, height); 
     try { 
      wallpaperManager.setBitmap(bitmap); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
    } 

} 

public void DisplayImageCircle(String url, ImageView imageView) { 
    imageViews.put(imageView, url); 
    Bitmap bitmap = memoryCache.get(url); 
    if (bitmap != null) 
     imageView.setImageBitmap(bitmap); 
    else { 
     queuePhoto(url, imageView); 
     imageView.setImageResource(stub_id); 
    } 

} 

private void queuePhoto(String url, ImageView imageView) { 
    PhotoToLoad p = new PhotoToLoad(url, imageView); 
    executorService.submit(new PhotosLoader(p)); 
} 

private Bitmap getBitmap(String url) { 
    File f = fileCache.getFile(url); 

    // from SD cache 
    Bitmap b = decodeFile(f); 
    if (b != null) 
     return b; 

    // from web 
    try { 
     Bitmap bitmap = null; 
     URL imageUrl = new URL(url); 
     HttpURLConnection conn = (HttpURLConnection) imageUrl 
       .openConnection(); 
     conn.setConnectTimeout(6000000); 
     conn.setReadTimeout(6000000); 
     conn.setInstanceFollowRedirects(true); 
     InputStream is = conn.getInputStream(); 
     OutputStream os = new FileOutputStream(f); 
     Utils.CopyStream(is, os); 
     os.close(); 
     bitmap = decodeFile(f); 
     return bitmap; 
    } catch (Exception ex) { 
     ex.printStackTrace(); 
     return null; 
    } 
} 

// decodes image and scales it to reduce memory consumption 
private Bitmap decodeFile(File f) { 
    try { 
     // decode image size 
     BitmapFactory.Options o = new BitmapFactory.Options(); 
     o.inJustDecodeBounds = true; 
     BitmapFactory.decodeStream(new FileInputStream(f), null, o); 

     // Find the correct scale value. It should be the power of 2. 

     int width_tmp = o.outWidth, height_tmp = o.outHeight; 
     int scale = 1; 
     while (true) { 
      if (width_tmp/2 < REQUIRED_SIZE 
        || height_tmp/2 < REQUIRED_SIZE) 
       break; 
      width_tmp /= 2; 
      height_tmp /= 2; 
      scale *= 2; 
     } 

     // decode with inSampleSize 
     BitmapFactory.Options o2 = new BitmapFactory.Options(); 
     o2.inSampleSize = scale; 
     return BitmapFactory.decodeStream(new FileInputStream(f), null, o2); 
    } catch (FileNotFoundException e) { 
    } 
    return null; 
} 

// Task for the queue 
private class PhotoToLoad { 
    public String url; 
    public ImageView imageView; 

    public PhotoToLoad(String u, ImageView i) { 
     url = u; 
     imageView = i; 
    } 
} 

class PhotosLoader implements Runnable { 
    PhotoToLoad photoToLoad; 

    PhotosLoader(PhotoToLoad photoToLoad) { 
     this.photoToLoad = photoToLoad; 
    } 

    @Override 
    public void run() { 
     if (imageViewReused(photoToLoad)) 
      return; 
     Bitmap bmp = getBitmap(photoToLoad.url); 
     memoryCache.put(photoToLoad.url, bmp); 
     if (imageViewReused(photoToLoad)) 
      return; 
     BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad); 
     Activity a = (Activity) photoToLoad.imageView.getContext(); 
     a.runOnUiThread(bd); 
    } 
} 

boolean imageViewReused(PhotoToLoad photoToLoad) { 
    String tag = imageViews.get(photoToLoad.imageView); 
    if (tag == null || !tag.equals(photoToLoad.url)) 
     return true; 
    return false; 
} 

// Used to display bitmap in the UI thread 
class BitmapDisplayer implements Runnable { 
    Bitmap bitmap; 
    PhotoToLoad photoToLoad; 

    public BitmapDisplayer(Bitmap b, PhotoToLoad p) { 
     bitmap = b; 
     photoToLoad = p; 
    } 

    @Override 
    public void run() { 
     if (imageViewReused(photoToLoad)) 
      return; 
     if (bitmap != null) 
      photoToLoad.imageView.setImageBitmap(bitmap); 
     else 
      photoToLoad.imageView.setImageResource(stub_id); 
    } 
} 

public void clearCache() { 
    memoryCache.clear(); 
    fileCache.clear(); 
} 

}

我也尝试在doInBackground()上运行imageLoader，但它没用。请帮忙!!

来源

2014-07-26 Prashant Yadav

设置您的网址也ImageView的

imageView.setTag(yourURL); 
imageLoader.DisplayImage(imageList.get(position), imageView);

来源

2014-07-26 11:33:34

不要误解我的意思，但我不明白它会如何帮助。你能解释一下你的答案吗？ –

@PrashantYadav当你设置方法DisplayImage你只传递两个参数第一个Url和第二个Imageview 在Imageloader库下载使用线程，更多图像多线程运行后台，如果该URL是空的，然后通过imagesview标签查找。第二件事之前在Imageview中设置图片比较URL和标签。 –

先生，你可以在http://imgur.com/wJBfHZq看到，一些图像显示正常，但一些图像只显示图像的一部分，它会有帮助吗？ –

你可以去第三方库从URL

加载图像您将获得以下好处：

Multithread image loading (async or sync) 
    Wide customization of ImageLoader's configuration (thread executors, downloader, decoder, memory and disk cache, display image options, etc.) 
    Many customization options for every display image call (stub images, caching switch, decoding options, Bitmap processing and displaying, etc.) 
    Image caching in memory and/or on disk (device's file system or SD card) 
    Listening loading process (including downloading progress)

1）Universal Image loader

2）Picasso

3）Volley

来源

2014-07-26 11:45:07

安卓：在imageview的

回答

相关问题