android listview刷新期间的空指针异常
我想在下载完成后更新我的列表视图，但它给了我Nullpointer异常我的代码是根据下
try {
URL url = new URL(GlobalVariable.Getstr());
HttpURLConnection c = (HttpURLConnection) url.openConnection();
c.setRequestMethod("GET");
c.setDoOutput(true);
c.connect();
int lenghtOfFile = c.getContentLength();
Log.d("ANDRO_ASYNC", "Lenght of file: " + lenghtOfFile);
String PATH = Environment.getExternalStorageDirectory()
+ "/download/";
Log.v(LOG_TAG, "PATH: " + PATH);
File file = new File(PATH);
file.mkdirs();
// String fileName = "workTest.mp3";
String fileName = GlobalVariable.Getstrpath().toString();
File outputFile = new File(file, fileName);
FileOutputStream fos = new FileOutputStream(outputFile);
InputStream is = c.getInputStream();
byte[] buffer = new byte[1024];
// int len1 = 0;
long total = 0;
// while ((len1 = is.read(buffer)) != -1) {
// total += len1;
// publishProgress(""+(int)((total*100)/lenghtOfFile));
// fos.write(buffer, 0, len1);
//
while ((count = is.read(buffer)) != -1) {
total += count;
publishProgress(""+(int)((total*100)/lenghtOfFile));
fos.write(buffer, 0, len1);
}
fos.close();
is.close();
// ArrayAdapter aa=new ArrayAdapter(FindFilesByType.this, android.R.layout.test_list_item,Ringtones);
// aa.setNotifyOnChange(true);
// lv1.setAdapter(aa);
try{
((ArrayAdapter) lv1.getAdapter()).notifyDataSetChanged();
// adapter.notifyDataSetChanged();
}
catch (Exception e) {
Log.i(LOG_TAG, "Error: " + e.toString());
}
我得到了
04-28 15:56:17.198: INFO/app(624): Error: java.lang.NullPointerException
我在做什么错？
提前致谢
线路异常来了。
并使用notifyDataSetChanged（）; 方法而不是lvl.getAdapter（）。 notifyDataSetChanged（）;
编辑： notifydatasetChange看到这一点
希望能帮助到你..
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