Question

我正在制作android应用程序..其中我已经将我的图像字符串编码到外部卡中的外部文件..但是当我读取该文件以显示图像....应用程序崩溃.. 这是一个代码：

storedpic.setOnClickListener(new View.OnClickListener() {

    ImageView storedimageView = (ImageView) findViewById(R.id.imageView3);

    public void onClick(View v) {
        File sdcard = Environment.getExternalStorageDirectory();

        File readfile = new File(sdcard, "myfile.txt");

        try {
            BufferedReader br = new BufferedReader(new FileReader(readfile));
            String test;
            while (true) {
                test = br.readLine();
                // readLine() returns null if no more lines in the file
                byte[] bytarray = Base64.decode(test, Base64.DEFAULT);
                Bitmap bmimage = BitmapFactory
                        .decodeByteArray(bytarray, 0, bytarray.length);
                storedimageView.setImageBitmap(bmimage);

                if (test == null)
                    break;

            }

        }

        catch (IOException e) {

            Toast.makeText(getBaseContext(), "Can't read a file", Toast.LENGTH_LONG).show();
        }

    }
});

Answer 1

由于输入NPE为String，Base64#decode投掷null的可能性很大。尝试替换

while (true) {
   test = br.readLine();
   ...
}

与

while ((test = br.readLine()) != null) {
   ...
}

当然会删除break声明

从android中的外部文件中读取图像字符串

1 个答案: