我如何实现异步任务这一形象有何看法？ [英] How do I implement this image view in an async task?

问题描述

我必须传递给一个活动的网址，我试图表现出从网址全屏幕上的图像，但它抛出一个主网线异常。

这是我能找到我认为我必须把方法异步任务，但是我似乎无法理解它在所有。所以，我将如何把这个方法在异步任务？

FullScreenImageView.java

 公共类FullscreenImageView延伸活动{
@覆盖
保护无效的onCreate（捆绑savedInstanceState）{
    super.onCreate（savedInstanceState）;    字符串URL = getIntent（）getStringExtra（SelectedImageURL）;    尝试{
        ImageView的I =（ImageView的）findViewById（R.id.imgView）;
        位图位图= BitmapFactory.de codeStream（（InputStream的）新的URL（网址）.getContent（））;
        i.setImageBitmap（位图）;
    }赶上（MalformedURLException的E）{
        e.printStackTrace（）;
    }赶上（IOException异常五）{
        e.printStackTrace（）;
    }}
}
 

解决方案

应该是这样的。
在 doInBackground 你得到的图像，并在 onPostExecute 设置为

 私有类DownloadFilesTask扩展的AsyncTask＆LT;弦乐，太虚，位图＆GT; {
     @覆盖
     保护位图doInBackground（字符串的URL ...）{
          位图位图= NULL;
          尝试{
              位= BitmapFactory.de codeStream（（InputStream的）新的URL（网址[0]）的getContent（））;
          }赶上（MalformedURLException的E）{
               e.printStackTrace（）;
          }赶上（IOException异常五）{
             e.printStackTrace（）;
          }
          返回位图;
     }
     @覆盖
     保护无效onPostExecute（位图位图）{
        ImageView的I =（ImageView的）findViewById（R.id.imgView）;
        i.setImageBitmap（位图）;
     }
 }
 

然后，你把它叫做你的的onCreate 方法内

 保护无效的onCreate（捆绑savedInstanceState）{
    super.onCreate（savedInstanceState）;
    字符串URL = getIntent（）getStringExtra（SelectedImageURL）;
    新DownloadFilesTask（）.execute（URL）;
}
 

I have an url passed to an activity and I am trying to show the image from the url full screen, however it throws a main network thread exception.

From what I can find I believe I have to put the method in an async task however I cannot seem to make sense of it at all. So how would I put this method in an async task?

FullScreenImageView.java

public class FullscreenImageView extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    String url = getIntent().getStringExtra("SelectedImageURL");



    try {
        ImageView i = (ImageView)findViewById(R.id.imgView);
        Bitmap bitmap = BitmapFactory.decodeStream((InputStream)new URL(url).getContent());
        i.setImageBitmap(bitmap);
    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

}
}

解决方案

It should be something like this. In the doInBackground you get the image, and in the onPostExecute you set it

private class DownloadFilesTask extends AsyncTask<String, Void, Bitmap>  {
     @Override
     protected Bitmap doInBackground(String... urls) {
          Bitmap bitmap = null; 
          try {
              bitmap = BitmapFactory.decodeStream((InputStream)new URL(urls[0]).getContent());
          } catch (MalformedURLException e) {
               e.printStackTrace();
          } catch (IOException e) {
             e.printStackTrace();
          }
          return bitmap;
     }
     @Override
     protected void onPostExecute(Bitmap bitmap) {
        ImageView i = (ImageView)findViewById(R.id.imgView);
        i.setImageBitmap(bitmap);
     }
 }

Then, you call it inside your onCreate method

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    String url = getIntent().getStringExtra("SelectedImageURL");
    new DownloadFilesTask ().execute(url); 
}

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