爲什麼圖像無法加載？

的XML文件如下：

<LinearLayout 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" 
    tools:context="${relativePackage}.${activityClass}" > 

    <ImageView 

     android:id="@+id/imageview" 
     android:layout_height="match_parent" 
     android:layout_width="match_parent" 
     android:visibility="visible" 
     android:layout_gravity="center" 
     android:contentDescription="@string/content_description" 
     /> 
</LinearLayout>

而且我Activity是繼到圖像加載到ImageView。作爲內部類實現AsyncTask。

public class LoadImageActivity extends Activity { 

    ImageView image ; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.load_image); 
     image = (ImageView)findViewById(R.id.imageview); 
     String url = "http://java.sogeti.nl/JavaBlog/wp-content/uploads/2009/04/android_icon_256.png"; 
     LoadImageAsync loadImageAsync = new LoadImageAsync(url, image); 
     loadImageAsync.execute(url);  

    }

在Activity的onCreate方法我稱爲AsyncTask加載圖像

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.load_image); 
    image = (ImageView)findViewById(R.id.imageview); 
    String url = "http://java.sogeti.nl/JavaBlog/wp-content/uploads/2009/04/android_icon_256.png"; 
    LoadImageAsync loadImageAsync = new LoadImageAsync(url, image); 
    loadImageAsync.execute(url);  

}

在AsyncTask I類有以下代碼這是我跟着the Stack Overflow link related to this。

AsyncTask類低於此類，我將其作爲Activity類的內部類實現。

public class LoadImageAsync extends AsyncTask<String, Void, Bitmap>{ 

    private String url; 
    private ImageView imageView; 

    public LoadImageAsync(String url, ImageView imageView) { 
      this.url = url; 
      this.imageView = imageView; 
     } 

    @Override 
    protected Bitmap doInBackground(String... params) {   


     try { 
      URL urlConnection = (URL) new URL(params[0]); 
      HttpURLConnection connection = (HttpURLConnection) urlConnection 
        .openConnection(); 
      connection.setDoInput(true); 
      connection.connect(); 
      InputStream input = connection.getInputStream(); 
      Bitmap myBitmap = BitmapFactory.decodeStream(input); 
      return myBitmap; 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
     return null; 

    } 

    @Override 
    protected void onPostExecute(Bitmap result) { 

     imageView.setImageBitmap(result); 
     super.onPostExecute(result); 
    } 

}

我做了什麼錯？或者錯過了什麼？

處理圖像時需要考慮什麼？

然後，這將移動到GridView加載圖像。

來源

2014-12-05 Karthikeyan Ve

變化從這裏'loadImageAsync.execute（URL）;''來loadImageAsync.execute（）;' – Piyush 2014-12-05 08:57:22

這個問題可能在你的ImageView的重點。嘗試致電requestLayout和/或invalidate：

@Override 
protected void onPostExecute(Bitmap result) { 
    imageView.requestLayout(); 
    imageView.setImageBitmap(result); 
    imageView.invalidate(); //try this if it still not working 
    super.onPostExecute(result); 
}

來源

2014-12-05 08:27:53

我會建議使用畢加索 Picasso.with（上下文）.load（「http://java.sogeti.nl/JavaBlog/wp-content/uploads/2009/04/android_icon_256.png」）.into（圖像）;

所以你不必擔心OutMemoryException這很可能會發生時，你會實現這個在GridView

來源

2014-12-05 08:32:04

使用AQuery從URL加載圖像：

AQuery水性=新AQuery（背景）;

aq.ajax(url, Bitmap.class, new AjaxCallback<Bitmap>() { 
     @Override 
     public void callback(String url, Bitmap object, AjaxStatus status) { 
     imageView.setImageBitmap(object); 
     } 
});

aq.id(imageView).image(url,true,true);

注：請更多的選項，提高圖片加載，緩存等

來源

2014-12-05 09:30:06

爲什麼圖像無法加載？

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