Progress dialog freeze when adding a large view in layout from onPost of AsyncTask. We have to add a dynamic layout so we have called that from onPost,( On calling that from doInBackground error occure, So we have called that from opPost) But now the progress dialog freeze when loading that layout.
Please Help...
I have created a separated class and called that class method
protected void onPostExecute(Void unused)
{
eLayout=new ExcelLayout(viewScreenActivity);
eLayout.LinearLayoutXLSView(ROW_HEIGHT, COL_WIDTH, ROW_Title_Width,NUM_COLS, NUM_ROWS, cols, rows, data);
progressdialog.dismiss();
}
Progress dialog freeze and disappear after task completed.
This problem raises when there is a huge process such as drawing a view happens in the main UI thread. The progress dialogs are very light weight process and when some other process takes priority then they just stop there without rotating (in simple) which makes it looks like it has hanged. But the actual reason is, there is some other process which takes more priority than showing the progress dialog.
In your case it is the View creation which takes priority. So what you have to do is, dismiss the dialog before starting to draw the layout.
But if you are looking for a way to show a progress dialog while you draw your view i am afraid it is not possible, from my experience so far.
EDIT
it is very much clear that your main UI does a lot of work. YOu can try this but I am not sure how far this will work. Instead of just calling the methods immediately after the progressdialog.dismiss(), you could use the dismiss listener and call the methods from there. For example,
progressDialog.setOnDismissListener(new OnDismissListener(){
public void onDismiss(DialogInterface dialog) {
eLayout=new ExcelLayout(viewScreenActivity);
eLayout.LinearLayoutXLSView(ROW_HEIGHT, COL_WIDTH, ROW_Title_Width,NUM_COLS, NUM_ROWS, cols, rows, data);
}});
So this gets called only when the progress dialog's progressdialog.dismiss(); is called. So it should work probably.
Related
Because you must include a legal notice when using google maps on android I added the following code to my fragment:
//in oncreate view method
_noticeMaps.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View view)
{
Toast.makeText(getActivity().getApplicationContext(), "Loading", Toast.LENGTH_LONG).show();
showLegalNotice();
}
});
public void showLegalNotice(){
_legalNotice = GooglePlayServicesUtil.getOpenSourceSoftwareLicenseInfo(getActivity());
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle("Legal Notice");
builder.setMessage(_legalNotice);
AlertDialog dialog = builder.create();
dialog.show();
}
Because the legal notice takes a long time to be placed in the setMessage the app shows the dialog after a few seconds (5+). Thats why i added the toast before the showLegalNotice to notice the user that its loading. However the toast shows after the dialog is loaded. Why isnt the toast showing before the dialog is loading? I call showLegalNotice AFTER i create the toast. I know i can fix it with threads but I want to understand why the toast is showing after the dialog is created.
The best solution is to put the legalNotice method codes in an AsyncTask. The Toast is shown after the dialog because you are doing the heavy work on the UI thread which is making it busy and that's why the toast is lagging behind.
If you don't know about AsyncTask, you can learn about it here. You can show the Toast in the preExecute() method of the AsyncTask. It will be guaranteed that the toast will be shown before any other action is taken.
UPDATE
Yes, you are right. The code is run in a sequential manner so the Toast should have been shown before the method runs. But try to think in a different way.
The Toast is an system UI component. You call show() on toast and your code moves to the next heavy or long-running task almost instantly.
There is always a slight delay for the toasts to be drawn or initiated on your screen and it also depends on various flavours of Android. So, before the toast starts to draw on the screen, the UI thread gets busy or jammed on performing a long-running task and looses frames.
Just when the long-running task of your method ends, the UI thread gets free once again and is able to resume drawing the toast. That is why, the toast is displayed, but always after the method completed its execution.
I need to do some work on the UI thread, specifically setting up some views, etc. - this can't be done in a background thread. The process is invoked on a button click and takes about a second or so to complete - without a progress dialog it looks as if the app is frozen. I use progress dialog with AsynTasks in several places and it works fine - however here I'm struggling.
I started with simple:
showDialog(DIALOG_PLEASE_WAIT);
viewInfo.setFromGuide(true); //this method just sets a variable
viewInfo.setVenue(venue); //this method does a lot of UI manipulation and takes a second or so
showScreen(VIEW_INFO); //this method shows the corresponding view in ViewFlipper
dismissDialog(DIALOG_PLEASE_WAIT);
However the dialog would not show (sort of expected, as this is all on UI thread.
Then I changed the code to this:
Handler hnd = new Handler() {
#Override
handleMessage(Message m) {
viewInfo.setFromGuide(true);
viewInfo.setVenue(venue);
showScreen(VIEW_INFO);
dismissDialog(DIALOG_PLEASE_WAIT);
}
}
showDialog(DIALOG_PLEASE_WAIT);
new Thread() {
public void run() {
hnd.sendEmptyMessage(0);
}
}.start();
This still doesn't show the dialog - naturally, the UI work in handleMessage is still done on the UI thread. So, what can I do to show the progress dialog?
If it takes really takes a second or so to complete than maybe you can just use a simple Toast notification with a message like "Please wait"
as you are using AsyncTask you can override onProgressUpdate which is called when ever you call publishProgress() from inside the doInBackGround so you can publish your results smoothly while working in background because, onProgressUpdate works on the UI thread.
I have a custom dialog and despite putting in all the code to inflate the view in its constructor, it seems like it takes much longer when the dialog is first launched compared to subsequent launches, as if only when i call dialog.show(); it actually creates it. How could I do what I intended, to properly preload the dialog to prevent this first run delay?
You can Extend your class with AsyncTask<> and perform all work in doInBackground().in onPreExecute() Show Dialog and in onPostExecute() remove the dialog from UI.
I want to make a Progress Dialog Box in my app to use when sending some information. But the code I wrote won't work. It the method send() executes but the dialog box never appears because it dismisses very quickly
Here is my code :
ProgressDialog myProgressDialog = ProgressDialog.show(Tents.this,
"Please wait...", "Sending...", true);
send();
myProgressDialog.dismiss();
goFour();
How do I make the Dialog Box Last a little longer?
First of all - you should not do send() in the same thread as show() and dismiss() - because you are effectively blocking UI thread during sending. The dialog will actually never show - because in order to show it after show() is called, you need to give the control back to the main looper in UI thread and simply finish handling whatever event you are handling. Otherwise the UI thread will never have a chance to draw your dialog.
The best idea is to start running send() in AsyncTask and call dismiss() in onPostExecute() (see http://developer.android.com/reference/android/os/AsyncTask.html to get idea how to run async task).
You are probably getting a progress dialog, but having it immediately dismiss as it has nothing to wait for.
I'll pretend you want this in OnCreate for my example:
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ProgressDialog pd = ProgressDialog.show(this, "Please wait...", "Sending...");
new Thread(new Runnable(){
public void run() {
send();
pd.dismiss();
}
}).start();
gofour();
}
EDIT: If it still goes away immediately, make sure send(); does something that actually takes some time. ;)
The UI thread is used to start send() , this will not work and progress dialog will not be shown .
Call send in another thread or AsynTask doBackground and on completion dismiss the dialog.
If your send action is completing so quickly that the dialog is not displaying properly, might I suggest instead using an indeterminate progress bar in the upper right corner of your activity via requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS) and then utilizing setProgressBarIndeterminateVisibility(true/false).
"I guess my real question would then be how do I make it so that it lasts a little longer?" My answer would be WHY???!!!
I think you would be better showing an alert dialog to confirm your send function has completed, it would be annoying for the user having to wait for no reason!
Error
05-12 11:56:45.793: ERROR/AndroidRuntime(505): Caused by: android.view.ViewRoot$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
what i have done
i have a list view inside my activity and i need to populate the listview by doing the following:
mylistview.setAdapter(new CustomAdapter());
now there is already too much pressure on my UI thread so , thought of calling this method inside a AsynTask.
Another problem
there is a progress dialog that shows in my acitivity when the user clicks the button to populate the listview. when i put everything inside one thread the progress dialog does not show. i had asked a question on stackoverflow about why the progress dialog does not show and i had got a reply saying that i need to put all the extra tasks inside another thread.
i have also read the updating UI in android given on android developer website:
but over there all we do is make a new runnable and post the runnable to the Handler of the UI thread so that when the UI is free, the runnable will be executed.
But how does the above solve my purpose? i mean the UI thread is still executing the instructions.
The only way i can take the load of the UI thread is if i make another thread and put all the work over there... but android does not allow this?
what is wrong with my understanding(if there is anything wrong)? How do i solve this problem
thank you in advance.
Android does allow you to put the extra work in a different thread AND publish the results on the UI thread, using AsyncTask. Add the UI update stage in the onPostExecute() method of the AsyncTask and you should be good-to-go. onPostExecute() is performed on the UI thread, the example in the AsyncTask Documentation is a great one.
Also, if you build your application properly, and don't use graphics a lot, there should not be too much work for the UI thread during the application run. Move everything that doesn't absolutely bound to the UI on a separate thread. AsyncTask is a very convenient way to do it.
AsyncTask is the correct way to solve your problem. Where you are running into difficulty is exactly what to put into the AsyncTask. Call mylistview.setAdapter(); from the onProgressUpdate or onPostExecute methods. So do something like this:
void setProgress(Integer progress){ myprogressbar.setValue(progress); }
void setAdapter(CustomAdapter result){ mylistview.setAdapter(result); }
private class LongRunningTask extends AsyncTask<String, Integer, CustomAdapter> {
protected Long doInBackground(String... urls) {
CustomAdapter res = null;
// do all the work to BUILD the custom adapter, calling publishProgress() as progress gets made
publishProgress(<progress value>);
return res;
}
protected void onProgressUpdate(Integer... progress) {
setProgress(progress);
}
protected void onPostExecute(CustomAdapter result) {
setAdapter(result);
}
}
That should fix the threading issue and let you set the progress bar.