Examples of ProgressBar and AsyncTask

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="20dp"
    android:orientation="vertical"
    tools:context="com.blogspot.android_er.androidprogressbar.MainActivity">

    <TextView
        android:id="@+id/title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="http://android-er.blogspot.com/"
        android:textStyle="bold"
        />

    <Button
        android:id="@+id/startprogress"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Start ProgressBar"/>

    <ProgressBar
        android:id="@+id/indeterminateBar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="gone" />

    <ProgressBar
        android:id="@+id/determinateBar1"
        style="@android:style/Widget.ProgressBar.Horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:progress="0"
        android:visibility="gone"/>
    <ProgressBar
        android:id="@+id/determinateBar2"
        style="@android:style/Widget.ProgressBar.Inverse"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="gone"/>
    <ProgressBar
        android:id="@+id/determinateBar3"
        style="@android:style/Widget.ProgressBar.Large"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="gone"/>
    <ProgressBar
        android:id="@+id/determinateBar4"
        style="@android:style/Widget.ProgressBar.Large.Inverse"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="gone"/>
    <ProgressBar
        android:id="@+id/determinateBar5"
        style="@android:style/Widget.ProgressBar.Small"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="gone"/>
    <ProgressBar
        android:id="@+id/determinateBar6"
        style="@android:style/Widget.ProgressBar.Small.Inverse"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="gone"/>
    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:src="@mipmap/ic_launcher"/>
</LinearLayout>

package com.blogspot.android_er.androidprogressbar;

import android.os.AsyncTask;
import android.os.Bundle;
import android.os.SystemClock;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.ProgressBar;

public class MainActivity extends AppCompatActivity {

    Button btnStartProgress;
    ProgressBar indeterminateBar;
    ProgressBar determinateBar1, determinateBar2, determinateBar3,
                determinateBar4, determinateBar5, determinateBar6;

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

        btnStartProgress = (Button)findViewById(R.id.startprogress);
        indeterminateBar = (ProgressBar)findViewById(R.id.indeterminateBar);
        determinateBar1 = (ProgressBar)findViewById(R.id.determinateBar1);
        determinateBar2 = (ProgressBar)findViewById(R.id.determinateBar2);
        determinateBar3 = (ProgressBar)findViewById(R.id.determinateBar3);
        determinateBar4 = (ProgressBar)findViewById(R.id.determinateBar4);
        determinateBar5 = (ProgressBar)findViewById(R.id.determinateBar5);
        determinateBar6 = (ProgressBar)findViewById(R.id.determinateBar6);

        btnStartProgress.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                btnStartProgress.setEnabled(false);
                MyAsyncTask myAsyncTask = new MyAsyncTask();
                myAsyncTask.execute();
            }
        });
    }

    public class MyAsyncTask extends AsyncTask<Void, Integer, Void> {

        @Override
        protected void onPreExecute() {
            indeterminateBar.setVisibility(View.VISIBLE);
            determinateBar1.setVisibility(View.VISIBLE);
            determinateBar1.setProgress(0);
            determinateBar2.setVisibility(View.VISIBLE);
            determinateBar3.setVisibility(View.VISIBLE);
            determinateBar4.setVisibility(View.VISIBLE);
            determinateBar5.setVisibility(View.VISIBLE);
            determinateBar6.setVisibility(View.VISIBLE);
        }

        @Override
        protected Void doInBackground(Void... voids) {
            for(int i=0; i<100; i++){
                publishProgress(i);
                SystemClock.sleep(100);
            }
            return null;
        }

        @Override
        protected void onProgressUpdate(Integer... values) {
            determinateBar1.setProgress(values[0]);
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            indeterminateBar.setVisibility(View.GONE);
            determinateBar1.setVisibility(View.GONE);
            determinateBar2.setVisibility(View.GONE);
            determinateBar3.setVisibility(View.GONE);
            determinateBar4.setVisibility(View.GONE);
            determinateBar5.setVisibility(View.GONE);
            determinateBar6.setVisibility(View.GONE);
            btnStartProgress.setEnabled(true);
        }
    }
}

Next:
- Custom ProgressBar with progressDrawable
- Add ProgressBar in ToolBar
- ProgressBar with SecondaryProgress
- Custom ProgressBar with SecondaryProgress
- Question of using ContentLoadingProgressBar