嗨,我的应用中有异步
例如: -
private class ProgressTask1 extends AsyncTask<String, Void, Boolean> {
private ProgressDialog dialog;
public ProgressTask1(MainActivity mainActivity) {
context = mainActivity;
dialog = new ProgressDialog(context);
}
private Context context;
protected void onPreExecute() {
this.dialog.setMessage("Checking system...");
this.dialog.setCancelable(false);
this.dialog.setTitle("Please Wait...");
this.dialog.setIcon(R.drawable.ic_launcher);
this.dialog.show();
}
现在,我希望那个setMessage更改我尝试在doinbackground中添加它
protected Boolean doInBackground(final String... args) {
dothis1();
this.dialog.setMessage("one done...");
dothis2();
this.dialog.setMessage("two done...");
这使应用程序关闭,并且不会对其进行低评分,因为我尝试了最好的和搜索的论坛,但能够解决这个问题,因此可以在这个不错的社区中进行解决:)
有人可以提供帮助吗?:)
错误
05-13 23:36:34.899:e/androidruntime(2454):引起: android.view.ViewRootimpl $ naterfromwrongthreadexception:仅 创建视图层次结构的原始线程可以触摸其视图。
ohmm,您不应从背景线程更新UI。要更新UI,您可以通过两种方式进行操作:
1)使用publishProgress (Progress... values)
和onProgressUpdate(...)
。为此,您必须更改AsynTask
类:
private class ProgressTask1 extends AsyncTask<String, String, Boolean> {
//.......... //your init
@Override
protected Boolean doInBackground(String... params) {
//your background handle
//publish to change UI
String toShow = "your_string_here";
publishProgress(toShow);
//return ...; //your return value
}
@Override
protected void onProgressUpdate(String... values) {
super.onProgressUpdate(values);
//detect message and show it.
//this.dialog.setMessage(values[0]);
}
}
2)使用onPostExecute(....)
:
private class ProgressTask1 extends AsyncTask<String, Void, Boolean> {
//.......... //your init
@Override
protected Boolean doInBackground(String... params) {
//your background handle
//return ...;//your return value
}
@Override
protected void onPostExecute(Boolean aBoolean) {
super.onPostExecute(aBoolean);
String toShow = "your_string_here";
//this.dialog.setMessage(toShow);
}
}
您无法从后台更新UI。
请参阅asynctask.onprogressupdate,以根据您的背景进度更新UI。:D