android - AsyncTask 不在 onCreate() 中执行

Question

我希望如果我的应用程序第一次启动，它应该从网络下载图像并将该图像存储在 Device/Emulator 中，从 Device/Emulator 应该显示在 ImageView 。我试过这种方式:

ImageView myImgView;

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

    myImgView = (ImageView) findViewById(R.id.imageView1);      

    new MyAsnyc();
     Log.d(MY_TAGT, "AsyncTask Executed.....");

}
private class MyAsnyc extends AsyncTask<Void, Void,Void>{
    public File file ;
    InputStream is;
    private Bitmap bitmap;
    protected void doInBackground() throws IOException{

        File path = Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_PICTURES);
        file = new File(path, "DemoPicture.jpg");
        try{
            // Make sure the Pictures directory exists.
            path.mkdirs();

            URL url = new      URL(BASE_URL);
            /* Open a connection to that URL. */
            URLConnection ucon = url.openConnection();

            /*
             * Define InputStreams to read from the URLConnection.
             */
            is = ucon.getInputStream();

            OutputStream os = new FileOutputStream(file);
            byte[] data = new byte[is.available()];
            is.read(data);
            Log.i(MY_TAGT, "Picture is readable........");
            os.write(data);
            Log.i(MY_TAGT, "Picture is Saved........");
            is.close();
            os.close();

        }
        catch (IOException e) {
            Log.d("ImageManager", "Error: " + e);
        }
    }
    @Override
    protected Void doInBackground(Void... params) {
        // TODO Auto-generated method stub

        try {
            doInBackground();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return null;
    }
    protected void onPostExecute(){

        try{
            // Tell the media scanner about the new file so that it is
            // immediately available to the user.

            MediaScannerConnection.scanFile(null,
                    new String[] { file.toString() }, null,
                    new MediaScannerConnection.OnScanCompletedListener() {
                public void onScanCompleted(String path, Uri uri) {
                    Log.i("ExternalStorage", "Scanned " + path + ":");
                    Log.i("ExternalStorage", "-> uri=" + uri);
                }
            });
        }
        catch (Exception e) {
            // TODO: handle exception

        }

        /*Here I want to set this image in ImageView*/

        bitmap = BitmapFactory.decodeFile(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString()+"/DemoPicture.jpg");
        myImgView.setImageBitmap(bitmap);
    }
}

但是这样MyAsync类没有被执行，请告知如何执行。

编辑这是我的日志

Answer 1

使用execute来调用它。

new MyAsnyc().execute();