AsyncTask的得到一个错误的字符串参数 [英] AsyncTask get a wrong String parameter

问题描述

我试图加载在AsyncTask的位图，在onclick我将执行myAsyncTask并得到位图作为结果。我坚持用NullPointerException异常，因为String参数，我把给myAsyncTack是德codeD错误的（见截图logcat中，第一行是字符串数据[位置]的log.d，第二个是从myAsyncTask德code法）。在我的code我需要打开大量的背景图片，我该怎么办它myAsyncTask吧？

I'm trying to load bitmaps in the asyncTask, in the onClick I will execute myAsyncTask and get bitmap as result. I'm stuck with NullPointerException, because String parameter, that I put to myAsyncTack is decoded wrong (see logcat screenshot, first line is log.d of String data[position], and the second is from myAsyncTask decode method). In my code I need to open lots of images at background, how can I do it right with myAsyncTask?

执行

        Log.d("Files", "DATA: " + data[position]);
        try{
            ImageView mImg = (ImageView) vi.findViewById(R.id.imageView);
            BitmapTask btmt = new BitmapTask();
            btmt.execute(data[position]);
            mImg.setImageBitmap(btmt.get());
        } catch (Exception e){
            e.printStackTrace();
        }


        return vi;

异步：

public class BitmapTask extends AsyncTask {

        @Override
        protected Bitmap doInBackground(String... bmt) {
            Bitmap bm = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory() + "/MANUAL/workflow/" + bmt);
            int targetWidth  = bm.getWidth() / 1;
            int targetHeight = bm.getHeight() / 1;

            Bitmap size = Bitmap.createBitmap(bm, 0, 0, targetWidth, targetHeight, matrix(), true);
            return size;
        }

        @Override
        protected void onPostExecute(Bitmap result) {

        }

    }

logcat的：

logcat:

推荐答案

更改此：

Bitmap bm = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory() + "/MANUAL/workflow/" + bmt);

这样：

Bitmap bm = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory() + "/MANUAL/workflow/" + bmt[0]);

您必须让字符串...的第一个元素BMT 字符串数组。

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