Develop Reference

Android ProgressDialog takes time to appear on screen

I have attached on click listener to a text view, inside on click listener a function say f1 is called and inside f1 another function say f2 is called.
Inside f2 I have created a android ProgressDialog object using current activity context, and called show function on progressDialog object. ProgressDialog takes time to appear on screen around 5-6 sec.
I have analyzed my code, but not able to understand why it takes this much time ?
textView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
ShowSyncDialog(); - f1
}
});
public void ShowSyncDialog()
{
fnSyncOfflineData(); - f2
}
public void fnSyncOfflineData()
{
ProgressDialog progressDialog = new ProgressDialog(context);
progressDialog.show();
//other code
}

You should call your functions in an AsyncTask. Also ProgressDialog must be shown at the beginning of this works. Use something like this:
public class YourTask extends AsyncTask<String, Void, String> {
private Context mContext;
private ProgressDialog progressDialog;
public YourTask(Context context) {
super();
mContext = context;
progressDialog = new ProgressDialog(context);
progressDialog.setMessage("Your Message");
}
#Override
protected void onPreExecute() {
super.onPreExecute();
progressDialog.show();
}
#Override
protected String doInBackground(String... values) {
// If you want to use 'values' string in here
String values = values[0];
String yourResult = yourFunction();
return yourResult;
}
#Override
protected void onPostExecute(String result) {
progressDialog.dismiss();
// Your task has done
...
}
}
Then call this task with:
new YourTask(YourActivity.this).execute();
You can change return type of task doInBackground method. This is just an example, you can search about AsyncTask.
Good luck.

Android Progress Bar appear and hide

I have a progress bar and I do not want to incorporate a numerical value to show the loading of some content. I just want that the ProgressBar should appear, animate and then go away.
I used:
public void buttonClick(View v){
ProgressBar mProgress=(ProgressBar)findViewById(R.id.my_progress);
mProgress.setVisibility(VISIBLE); //line 1..
//loading data from web... takes time
mProgress.setVisibility(INVISIBLE); //line 2..
}
but when I run this code, both line 1 and line 2 executes, but the UI changes afterwards, which is not desired. I want that when the button is clicked, the progress bar should appear and when the data is downloaded from the web the progress bar should disappear.
I tried setting the visibility from another thread, but it didn't work as UI changes are not allowed in other threads.

You download your data in AsyncTask right? Put this code
private class DownloadData extends AsyncTask<Void, Void, Void>{
#Override
protected void onPreExecute() {
super.onPreExecute();
mProgress.setVisibility(View.VISIBLE);
}
#Override
protected Void doInBackground(Void... params) {
// download your data here
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
mProgress.setVisibility(View.GONE);
}
}

The best way implement it by using an AsyncTask
MyTask.java
class MyTask extends AsyncTask<Void, Void, Void> {
ProgressDialog dialog;
Context context;
MyTask(Context context){
this.context=context;
}
#Override
protected void onPreExecute() {
dialog=new ProgressDialog(context);
dialog.setMessage("Please wait...");
dialog.setIndeterminate(true);
dialog.setCancelable(false);
dialog.show();
}
#Override
protected Void doInBackground(Void... params) {
//do your task here
}
#Override
protected void onPostExecute(Void result) {
if(dialog.isShowing()){
dialog.dismiss();
}
}
}
You can start the task like this:
public void buttonClick(View v){
new MyTask(YourActivity.this).execute();
}
You can modify the AsyncTask accordingly to retrieve the result.
Hope it helps. :)

ProgressDialog show too much late with Asynch task in Android

I am new in android. I am trying to display ProgressDialog when click on button .
This is my code:
// set listener
btn_Login.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
//progress.show();
MyAsynch asynch = new MyAsynch();
asynch.execute();
}
In this code progress dialog too much late appear when i am comment on Asynctask object then progress dialog appear normally.
I am puting my progress dialog in
AsynchTask method
onPreExecute() but same out put dialog display late .
How to solve my problem..??
I am also read stack answers following link but not solve my problem .
async task progress dialog show too late
ProgressDialog appears too late and dissapears too fast
here is my Asynctask code
private class MyAsynch extends AsyncTask<String, Void, String> {
ProgressDialog progress;
String login_stat;
String stat;
#Override
protected void onPreExecute() {
progress = new ProgressDialog(this);
progress.setTitle(" User Login ");
progress.setMessage("Please Wait!!");
progress.setCancelable(false);
progress.setIndeterminate(true);
progress.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progress.show();
}
#Override
protected String doInBackground(String... urls) {
try {
login_stat = s_ApiHandling.doLogin(m_Et_Username.getText()
.toString().trim(), m_Et_Password.getText()
.toString().trim());
} catch (Exception e) {
System.out.println("internet connection loss ");
stat = "ERORR";
e.printStackTrace();
}
return stat;
}
#Override
protected void onPostExecute(String status) {
progress.dismiss();
}
}

You are probably doing too much in onPreExecute

Remove progress.cancel() from your doInBackground method and put it in to a onPostExecute method in your AsyncTask (like the second link you posted)
You shouldn't have anything talking to the UI in a background thread - that should all be done in pre/post execution.

you code should look like this:
AsyncTask<String, Void, String>()
{
private ProgressDialog progressDialog = ProgressDialog.show(this, "", "Loading...");
#Override
protected void onPostExecute(String result)
{
progressDialog.dismiss();
}
#Override
protected String[] doInBackground(String... params)
{
//ALL CODE GOES HERE.
}
}
When you call the asynctask you must not use the get() method or the progress dialog won't work correctly.

AsyncTask not showing the ProgressDialog

I am using an AsyncTask (which I am starting in my main activity) to load some data:
Context context = VehicleTabView.this;
ProgressDialog progressDialog = new ProgressDialog(context);
progressDialog.setMessage("Loading...");
new LoadingVehicles(context, progressDialog).execute(null, null, null);
Here is the AsyncClass:
package com.example.schedule_vehicles;
import com.example.utils.VehicleNames;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
// Showing a ProgressDialog once loading the list of vehicles is completed using an AsyncTask
public class LoadingVehicles extends AsyncTask<Void, Void, Void> {
Context context;
ProgressDialog progressDialog;
public LoadingVehicles(Context context, ProgressDialog progressDialog) {
this.context = context;
this.progressDialog = progressDialog;
}
#Override
protected void onPreExecute() {
progressDialog.show();
}
#Override
protected Void doInBackground(Void... params) {
new VehicleNames(context);
return null;
}
#Override
protected void onPostExecute(Void result) {
progressDialog.dismiss();
}
}
The problem that the ProgressDialog is not showing on the screen.
I type Log.d, to see if the program is going through all the phases - onPreExecute, doInBackground, onPostExecute, and it is going through all the phases and doing the job that I need. But the ProgressDialog is not showing. I read a lot of information about this thing and it seems that the PRE and POST execute are started by the main thread, which is blocked by the DOINBACKGROUND method, and this is the reason not to see the ProgressDialog. I tried to find some answer how this is solved - but no success.
If anyone faced this, please share your experience. THANKS a lot!

You're passing the ProgressDialog to the Task, just show() it before you start the AsyncTask, not from within the AsyncTask.

Your code looks good to me. You are correct about your understanding of Asynctask and your use of them also appears correct.
The only thing that I can think of is that you must make sure that you are calling execute() on the UI Thread as well. From the code posted I'm not able to tell what context you are in.
Make sure you can pass in "this" as a context. That will tell you if your on the UI thread or not.
ProgressDialog progressDialog = new ProgressDialog(this);

Try :
ProgressDialog progressDialog = new ProgressDialog([Activity Name].this);
Let me know if this solves the problem or I'll see in depth.

Maybe you are missing the context.
ProgressDialog progressDialog = new ProgressDialog(this);

Normally when creating a ProgressDialog, you use the static method ProgressDialog.show(context, title, message). This will create and show the message and give you back a reference to the dialog.
onPreExecute and onPostExecute are called on the main thread, and are not blocked by the doInBackground, which runs on another thread. onPreExecute is called before doInBackground and onPostExecute is called after.
Here's some example code:
public static class InitializeTask extends MyAsyncTask<String, String, Response<Object>> {
private Activity activity;
private ProgressDialog dialog;
public InitializeTask(Activity activity) {
this.activity = activity;
}
#Override
protected void onPreExecute() {
dialog = ProgressDialog.show(activity, null, "Initializing...");
}
#Override
protected void onPostExecute(Response<Object> result) {
if (dialog != null && dialog.isShowing())
dialog.dismiss();
}
#Override
protected Response<Object> doInBackground(String... params) {
}
#Override
protected void attach(Activity context) {
this.activity = context;
dialog = ProgressDialog.show(context, null, "Initialize...");
}
#Override
protected void detach() {
if (dialog.isShowing())
dialog.dismiss();
activity = null;
}
}
Attach and detach are my own methods for referencing a cross orientation changes.

ProgressDialog is not shown in the AsyncTask

Document doc = new Obtainer(context, uri).execute().get();
This code in the activity class renders the Obtainer(which extends AsyncTask) which gets the xml document from the url. This is the onPreExecute method:
protected void onPreExecute() {
super.onPreExecute();
System.out.println("Pre execute began");
exception = null;
dialog = new ProgressDialog(context);
dialog.setMessage("Loading started");
dialog.setIndeterminate(true);
dialog.setCancelable(false);
System.out.println("Preexecute end");
dialog.show();
}
context is set in the Constructor:
public Obtainer(Context c, String addr) {
context = c;
address = addr;
}
During the runtime I can see in the console output both "Pre execute began" and "Preexecute end" but the progress dialog is not shown. What is the probleM?

Use this code, it works for me:
class Obtainer extends AsyncTask<Void, Void, Void> {
private ProgressDialog dialog;
#Override
protected void onPreExecute() {
dialog = new ProgressDialog(App.this); // App - your main activity class
dialog.setMessage("Please, wait...");
dialog.show();
}
#Override
protected Void doInBackground(Void... params) {
// ...
}
#Override
protected void onPostExecute(Void result) {
dialog.dismiss();
}
}
And in your main activity class method call
new Obtainer().execute();

What Context are you passing when you create your Obtainer (AsyncTask subclass)?
If you are using the Application context via getApplicationContext(), it can not be used to create a Dialog (or any View for that matter). You need to pass it a Context that can create Views.
"If you're in the habit of using your application context (from a call to getApplicationContext(), for example) in places where you need a Context to create views, it's only a matter of time until you find a case where things don't work quite like you would want or expect."
From: https://plus.google.com/107708120842840792570/posts/VTeRBsAeyTi