Android - Simple Alert Dialog

[jon waek]

Operating System

Android

In this tutorial we will try to create a Simple Alert Dialog Using Android. Android is the world’s most widely used operating system with over a millions of user, that are already installed to smartphones, tablets, and even television. Android is an open source so that developer find it easy to develop and expand new features. So let's do the coding...

Getting Started:

First you will have to download & install the Android Development IDE (Android Studio or Eclipse). Android Studio is an open source development feel free to develop your things.

Here's the link for the Android Studio https://developer.android.com/studio/index.html.

Layout Design

We will now create the design for the application, first locate the activity_main.xml and click text to view the script. Then copy and paste the code below.

1. <?
   
   xml version=
   
   "1.0"
   
   encoding=
   
   "utf-8"
   
   ?>
   
2. <
   
   RelativeLayout xmlns:
   
   android=
   
   "http://schemas.android.com/apk/res/android"
   
3. xmlns:
   
   app=
   
   "http://schemas.android.com/apk/res-auto"
   
4. xmlns:
   
   tools=
   
   "http://schemas.android.com/tools"
   
5. android:
   
   layout_width=
   
   "match_parent"
   
6. android:
   
   layout_height=
   
   "match_parent"
   
7. tools:
   
   context=
   
   "com.razormist.simplealertdialog.MainActivity"
   
   >
   
8. 
   
9. 
   
10. <
    
    TextView
    
11. android:
    
    layout_height=
    
    "wrap_content"
    
12. android:
    
    layout_width=
    
    "wrap_content"
    
13. android:
    
    text=
    
    "Simple Alert Dialog"
    
14. android:
    
    textSize=
    
    "30sp"
    
15. android:
    
    layout_alignParentTop=
    
    "true"
    
16. android:
    
    layout_centerHorizontal=
    
    "true"
    
17. android:
    
    layout_marginTop=
    
    "20dp"
    
18. android:
    
    id=
    
    "@+id/tv_title"
    
    />
    
19. 
    
20. <
    
    Button
    
    
    
21. android:
    
    id=
    
    "@+id/btn_click"
    
22. android:
    
    layout_width=
    
    "wrap_content"
    
23. android:
    
    layout_height=
    
    "wrap_content"
    
24. android:
    
    layout_centerInParent=
    
    "true"
    
25. android:
    
    text=
    
    "Click Here"
    
    />
    
26. 
    
27. </
    
    RelativeLayout>
    

Android Manifest File

The Android Manifest file provides essential information about your app to the Android system in which the system must required before running the code.

1. <?
   
   xml version=
   
   "1.0"
   
   encoding=
   
   "utf-8"
   
   ?>
   
2. <
   
   manifest xmlns:
   
   android=
   
   "http://schemas.android.com/apk/res/android"
   
3. package
   
   =
   
   "com.razormist.simplealertdialog"
   
   >
   
4. 
   
5. <
   
   application
   
6. android:
   
   allowBackup=
   
   "true"
   
7. android:
   
   icon=
   
   "@mipmap/ic_launcher"
   
8. android:
   
   label=
   
   "@string/app_name"
   
9. android:
   
   roundIcon=
   
   "@mipmap/ic_launcher_round"
   
10. android:
    
    supportsRtl=
    
    "true"
    
11. android:
    
    theme=
    
    "@Style/AppTheme"
    
    >
    
12. <
    
    activity android:
    
    name=
    
    ".MainActivity"
    
13. android:
    
    configChanges=
    
    "orientation"
    
14. android:
    
    screenOrientation=
    
    "portrait"
    
    >
    
15. <
    
    intent-
    
    filter>
    
16. <
    
    action android:
    
    name=
    
    "android.intent.action.MAIN"
    
    />
    
17. 
    
18. <
    
    category android:
    
    name=
    
    "android.intent.category.LAUNCHER"
    
    />
    
19. </
    
    intent-
    
    filter>
    
20. </
    
    activity>
    
21. </
    
    application>
    
22. </
    
    manifest>
    

The Main Function

This code contains the main function of the application. This code will generate a dialog to prompt the user to what to do next when the button is clicked. To create first locate your java file and open it, then write these blocks of code.

1. package
   
   com.razormist.simplealertdialog
   
   ;
   
2. 
   
3. import
   
   android.app.Application
   
   ;
   
4. import
   
   android.content.DialogInterface
   
   ;
   
5. import
   
   android.support.v7.app.AlertDialog
   
   ;
   
6. import
   
   android.support.v7.app.AppCompatActivity
   
   ;
   
7. import
   
   android.os.Bundle
   
   ;
   
8. import
   
   android.util.Log
   
   ;
   
9. import
   
   android.view.View
   
   ;
   
10. import
    
    android.widget.Button
    
    ;
    
11. import
    
    android.widget.TextView
    
    ;
    
12. 
    
13. public
    
    class
    
    MainActivity extends
    
    AppCompatActivity {
    
14. 
    
15. Button
    
    btn_click;
    
16. 
    
17. 
    
18. @Override
    
19. protected
    
    void
    
    onCreate(
    
    Bundle savedInstanceState)
    
    {
    
20. super
    
    .onCreate
    
    (
    
    savedInstanceState)
    
    ;
    
21. setContentView(
    
    R.layout
    
    .activity_main
    
    )
    
    ;
    
22. 
    
23. btn_click =
    
    (
    
    Button
    
    )
    
    findViewById(
    
    R.id
    
    .btn_click
    
    )
    
    ;
    
24. 
    
25. btn_click.setOnClickListener
    
    (
    
    new
    
    View
    
    .OnClickListener
    
    (
    
    )
    
    {
    
26. @Override
    
27. public
    
    void
    
    onClick(
    
    View
    
    v)
    
    {
    
28. 
    
29. AlertDialog.Builder
    
    builder=
    
    new
    
    AlertDialog.Builder
    
    (
    
    MainActivity.this
    
    )
    
    ;
    
30. builder.setMessage
    
    (
    
    "Are you sure you want to exit?"
    
    )
    
31. .setTitle
    
    (
    
    "System Configuration"
    
    )
    
32. .setCancelable
    
    (
    
    false
    
    )
    
33. .setPositiveButton
    
    (
    
    "YES"
    
    , new
    
    DialogInterface.OnClickListener
    
    (
    
    )
    
    {
    
34. @Override
    
35. public
    
    void
    
    onClick(
    
    DialogInterface dialog, int
    
    which)
    
    {
    
36. moveTaskToBack(
    
    true
    
    )
    
    ;
    
37. android.os
    
    .Process
    
    .killProcess
    
    (
    
    android.os
    
    .Process
    
    .myPid
    
    (
    
    )
    
    )
    
    ;
    
38. System
    
    .exit
    
    (
    
    1
    
    )
    
    ;
    
39. }
    
    }
    
    )
    
40. .setNegativeButton
    
    (
    
    "NO"
    
    , new
    
    DialogInterface.OnClickListener
    
    (
    
    )
    
    {
    
41. @Override
    
42. public
    
    void
    
    onClick(
    
    DialogInterface dialog, int
    
    which)
    
    {
    
43. dialog.cancel
    
    (
    
    )
    
    ;
    
44. }
    
45. }
    
    )
    
    ;
    
46. 
    
47. AlertDialog alert =
    
    builder.create
    
    (
    
    )
    
    ;
    
48. alert.show
    
    (
    
    )
    
    ;
    
49. }
    
50. }
    
    )
    
    ;
    
51. }
    
52. }
    

There you have it we successfully created a Simple Alert Dialog using android. I hope that this tutorial help you to what you are looking for. For more updates and tutorials just kindly visit this site. Enjoy Coding!!

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