如何从AsyncTask的得到一个位图并将其设置为我的形象 [英] How do I get a bitmap from AsyncTask and set it to my image

问题描述

我想使用的AsyncTask将图像URL转换为位图，以便将其设置为一个图像。我不明白如何让位图出的AsyncTask的，这样我可以将其设置为我的我创建在一个循环中的图像。我还试图位图设置为内部的AsyncTask图像。我的理解是，一切都要里面的AsyncTask做，但我不能引用图片我想设置的值。

我研究的URL转换位图和AsyncTask的，但我无法弄清楚如何将它们结合起来，得到我想要的东西。这已经是一个相当普遍的任务。为什么这么难呢？

我如何引用我的图片AsyncTask的？

我能回到我的位图，然后将其设置为图像外的AsyncTask的？

有没有设定一个URL作为图像源的更简单的方法？

我已经包括了我有这么远。<​​/ P>

感谢您的帮助，并抽出时间来阅读。

 类BitmapTaks扩展的AsyncTask＆LT;弦乐，太虚，位图＆GT; {公共位图doInBackground（字符串的URL ...）{
        位图BM = NULL;
        尝试{
            网址aURL =新的URL（网址[0]）;
            康涅狄格州的URLConnection = aURL.openConnection（）;
            conn.connect（）;
            InputStream为= conn.getInputStream（）;
            二BufferedInputStream为=新的BufferedInputStream（是）;
            BM = BitmapFactory.de codeStream（之二）;
            bis.close（）;
            is.close（）;
       }赶上（IOException异常五）{
           Log.e（IMG，错误获取位图，E）;
       }
       返回BM;
}保护无效onPostExecute（位图BM）{
   //做一些事情后执行
}
}
 

解决方案

  

这已经是一个相当普遍的任务。为什么这么难呢？

我真的建议你看看到的Andr​​oid排球库 。它抽象掉这一切的AsyncTask样板code制成。下面是如何设置的图像位图一个非常好的例子。

  ImageLoader的ImageLoader的= AppController.getInstance（）getImageLoader（）。//如果您正在使用正常的ImageView
imageLoader.get（Const.URL_IMAGE，新ImageListener（）{@覆盖
公共无效onErrorResponse（VolleyError错误）{
Log.e（TAG，图像加载错误：+ error.getMessage（））;
}@覆盖
公共无效onResponse（ImageContainer响应，布尔ARG1）{
如果（response.getBitmap（）！= NULL）{
//加载图像插入的ImageView
imageView.setImageBitmap（response.getBitmap（））;
}
}
}）;
 

您可以阅读从这里更多： HTTP： //www.androidhive.info/2014/05/android-working-with-volley-library-1/

I am trying to use an AsyncTask to convert an image URL to a bitmap in order to set it to an image. I don't understand how to get the bitmap out of the AsyncTask so that I can set it to my the images I am creating in a loop. I also have tried to set the bitmap to the image inside AsyncTask. My understanding is that everything must be done inside AsyncTask but I am unable to reference the images I want to set the value for.

I have researched the URL to bitmap conversion and the AsyncTask but I can't figure out how to combine them to get what I want. This has to be a fairly common task. Why is it so difficult?

How do I reference my images in AsyncTask?

Can I return my bitmap and then set it to the image outside of AsyncTask?

Is there an easier way to set a URL as an image source?

I have included what I have so far.

Thank you for your help and taking the time to read this.

class BitmapTaks extends AsyncTask<String, Void, Bitmap> {

public Bitmap doInBackground(String... urls) {
        Bitmap bm = null;
        try {
            URL aURL = new URL(urls[0]);
            URLConnection conn = aURL.openConnection();
            conn.connect();
            InputStream is = conn.getInputStream();
            BufferedInputStream bis = new BufferedInputStream(is);
            bm = BitmapFactory.decodeStream(bis);
            bis.close();
            is.close();
       } catch (IOException e) {
           Log.e("img", "Error getting bitmap", e);
       }
       return bm;
}

protected void onPostExecute(Bitmap bm) {
   //do something after execute


}
}

解决方案

This has to be a fairly common task. Why is it so difficult?

I'd really recommend you take a look into the Android Volley library. It's made to abstract away all this AsyncTask boilerplate code. Here's a very nice example of how to set an image bitmap

ImageLoader imageLoader = AppController.getInstance().getImageLoader();
 
// If you are using normal ImageView
imageLoader.get(Const.URL_IMAGE, new ImageListener() {
 
    @Override
    public void onErrorResponse(VolleyError error) {
        Log.e(TAG, "Image Load Error: " + error.getMessage());
    }
 
    @Override
    public void onResponse(ImageContainer response, boolean arg1) {
        if (response.getBitmap() != null) {
            // load image into imageview
            imageView.setImageBitmap(response.getBitmap());
        }
    }
});

You can read more from here: http://www.androidhive.info/2014/05/android-working-with-volley-library-1/

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