Android_Slip_1B

Step1:

Open Android Studio and create a new project with an Empty Activity template.

In the res/layout/activity_main.xml file, add a Button widget:

<Button
android:id="@+id/buttonShowProgressDialog"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Show ProgressDialog"
android:onClick="showProgressDialog"/>

In the MainActivity.java file, implement the showProgressDialog method and create an AsyncTask to simulate a background task:

import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}

public void showProgressDialog(View view) {
new BackgroundTask().execute();
}

private class BackgroundTask extends AsyncTask {
private ProgressDialog progressDialog;

@Override
protected void onPreExecute() {
super.onPreExecute();
progressDialog = new ProgressDialog(MainActivity.this);
progressDialog.setMessage("Loading...");
progressDialog.setCancelable(false);
progressDialog.show();
}

@Override
protected Void doInBackground(Void... params) {

try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
return null;
}

@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
if (progressDialog.isShowing()) {
progressDialog.dismiss();
}
}
}
}

Step2:

Run the application, and when you click the "Show ProgressDialog" button, a ProgressDialog will appear, simulating a background task. After a simulated delay, the ProgressDialog will be dismissed.