You are not calling dialog.show()
in onPreExecute
method of your AsyncTask
.
Use Asynctask to display a ProgressBar in Android
-
01-07-2023 - |
Pregunta
I am trying to do display a ProgressBar.
I am an Android beginner.
When I press the button, the task should be running in the background, but it does not display the ProgressBar.
What is problem? I cannot understand.
Please help me!
MainActivity:
package com.example.shikkok_services;
import java.util.ArrayList;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity {
private Button btnThread,btntask;
private ProgressDialog pd;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnThread=(Button)findViewById(R.id.btnStartThread);
btntask=(Button)findViewById(R.id.btntsk);
btntask.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
//start myTast
new MyTask(MainActivity.this).execute();
}
});
}
}
MyTask:
package com.example.shikkok_services;
import android.app.Dialog;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
public class MyTask extends AsyncTask<Void, Integer, Void> {
Context context;
Handler handler;
Dialog dialog;
TextView txtprogrss;
ProgressBar progress;
Button btnCancel;
MyTask(Context context, Handler handler){
this.context=context;
this.handler=handler;
}
MyTask(Context context){
this.context=context;
this.handler=handler;
}
@Override
protected void onPreExecute() {
super.onPreExecute();
// create dialog
dialog=new Dialog(context);
dialog.setCancelable(true);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.setContentView(R.layout.pogressdialog);
txtprogrss=(TextView) dialog.findViewById(R.id.txtProgress);
progress=(ProgressBar)dialog.findViewById(R.id.progressBar2);
btnCancel=(Button)dialog.findViewById(R.id.btnProgress);
btnCancel.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
MyTask.this.cancel(true);
}
});
}
@Override
protected Void doInBackground(Void... arg0) {
for (int i = 0; i < 100; i++) {
if(isCancelled()){
break;
}else{
Log.e("In Background","current value;"+ i);
publishProgress(i);
try {
Thread.sleep(500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return null;
}
@Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
progress.setProgress(values[0]);
txtprogrss.setText("progress update"+ values[0]+"%");
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
dialog.dismiss();
Toast.makeText(context, "Finished", Toast.LENGTH_LONG).show();
}
}
Solución 2
Otros consejos
You forgot to call dialog.show()
at the onPreExecute()
Use ProgressDialog
. You don't need any layout in this case.
ProgressDialog progressDialog = new ProgressDialog(context);
in onPreExecute
show it
progressDialog.show();
and in onPostExecute
dissmiss it
progressDialog.dismiss();
Add to OnPostExecute method :
pg.setVisibility(View.INVISIBLE);
Add to onPreExecute method :
pg.setVisibility(View.VISIBLE);
and in Layout file you should add to progress bar :
android:visibility="invisible"
You created the dialog but not showing it anywhere. Your onPreExecute() should look like:
@Override
protected void onPreExecute() {
super.onPreExecute();
// create dialog
dialog=new Dialog(context);
dialog.setCancelable(true);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.setContentView(R.layout.pogressdialog);
txtprogrss=(TextView) dialog.findViewById(R.id.txtProgress);
progress=(ProgressBar)dialog.findViewById(R.id.progressBar2);
btnCancel=(Button)dialog.findViewById(R.id.btnProgress);
btnCancel.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
MyTask.this.cancel(true);
dialog.dismiss(); //On button click cancel AsyncTask and dismiss dialog
}
});
dialog.show(); //Show the dialog
}
You also need to dismiss the dialog when clicked on btnCancel.
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