我正在研究 Android AsyncTask,我希望在我的程序加载期间制作一个进度条。这是我的制作方法。
A class is declared here...
private ArrayList<String> result1 = new ArrayList<String>(); //class variable
onCreate()
{
Some stuff here...
new ATask().execute();
for (int i = 0; i <result1.size();i++)
{
output = output +result1.get(i) + "\n\n";
}
textView.setText(output);
}
private void do0()
{
ArrayList<Sentence> result = new ArrayList<Sentence>();
ArrayList<String> result2 = new ArrayList<String>();
result = do1("link", true); //just some function I am working
result1 = do2(result,10);//do2 return ArrayList<String>
}
private class ATask extends AsyncTask<String, Void, String>{
private ProgressDialog progress = null;
@Override
protected String doInBackground(String... params) {
do0();
return null;
}
@Override
protected void onCancelled() {
super.onCancelled();
}
@Override
protected void onPostExecute(String result) {
progress.dismiss();
//adapter.notifyDataSetChanged();
super.onPostExecute(result);
}
@Override
protected void onPreExecute() {
progress = new ProgressDialog(ReadWebPage.this);
progress.setMessage("Doing...");
progress.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progress.show();
super.onPreExecute();
}
@Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
};
我的意图是,在加载进度条时,它会完成do0()
并修改result1
,然后我oncreate
可以用它result1
来显示在它的TextView
. 但是TextView
,在此设置中,我的始终是空的。所以我移动
for (int i = 0; i <result1.size();i++)
{
output = output +result1.get(i) + "\n\n";
}
textView.setText(output);
进入do0()
(在 之后result1 = do2()
),但随后程序将崩溃。我对这些线程设置不熟悉,提前感谢您的帮助。