有人可以告诉我这段代码哪里出错了吗?基本上我希望应用程序下载一个.png文件,将其显示给用户,并将其保存到SD卡以供将来参考。它似乎一切正常,直到while ((len = webstream.read(buffer)) > 0)
部分;因为调试器没有达到我放在这里的断点,我有一个空的.png文件的目录。我在我的Manifest中声明了WRITE_EXTERNAL_STORAGE
权限。SD卡写入失败?
protected class DownloadTask extends AsyncTask<String, Integer, Bitmap> {
@Override
protected Bitmap doInBackground(String... string) {
Bitmap d = null;
try {
DefaultHttpClient dhc = new DefaultHttpClient();
HttpGet request = new HttpGet(HTTP_BASE + string[0] + ".png");
HttpResponse response = dhc.execute(request);
BufferedInputStream webstream = new BufferedInputStream(response.getEntity().getContent());
d = BitmapFactory.decodeStream(webstream);
writeToSd(string[0], webstream, d);
}
catch (Exception ex) { ex.printStackTrace(); }
return d;
}
private void writeToSd(String string, BufferedInputStream webstream, Bitmap d) {
try {
webstream.mark(3);
webstream.reset();
File f = new File(Environment.getExternalStorageDirectory() + SD_DIR);
f.mkdirs();
File f2 = new File(f, string + ".png");
f2.createNewFile();
BufferedOutputStream fos = new BufferedOutputStream(new FileOutputStream(f2));
int len;
byte[] buffer = new byte[1024];
while ((len = webstream.read(buffer)) > 0) {
fos.write(buffer, 0, len);
}
webstream.close();
//fos.flush();
fos.close();
}
catch (Exception ex) {
ex.printStackTrace();
}
}
protected void onPostExecute(Bitmap result) {
if (result != null) {
iv.setImageBitmap(result);
vs.setDisplayedChild(1);
}
}
};
是的,试过这个,它工作出色,谢谢! – 2010-10-02 12:55:06