Introduction

In this article, you will learn how to validate edit text in Android.
Validation
 Validation is a process to ensure that the value entered by the user is within the accepted boundaries of the application. For example, if a user enters a name then the programmer validates the edit text in such a way that it consists of only letters but no numeric values.
Step 1
Create a new project.
9.jpg
Step 2
Now open the XML file:
  1. <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  2. xmlns:tools="http://schemas.android.com/tools"
  3. android:layout_width="match_parent"
  4. android:layout_height="match_parent"
  5. android:paddingLeft="@dimen/activity_horizontal_margin"
  6. android:paddingRight="@dimen/activity_horizontal_margin"
  7. android:paddingTop="@dimen/activity_vertical_margin"
  8. android:paddingBottom="@dimen/activity_vertical_margin"
  9. tools:context=".MainActivity">
  10. <LinearLayout
  11. android:layout_width="wrap_content"
  12. android:layout_height="wrap_content"
  13. android:layout_alignParentTop="true"
  14. android:orientation="horizontal" android:id="@+id/linearLayout2">
  15. <TextView
  16. android:layout_width="wrap_content"
  17. android:layout_height="wrap_content"
  18. android:textAppearance="?android:attr/textAppearanceLarge"
  19. android:text="Person_Name"
  20. android:id="@+id/textView1"
  21. android:layout_gravity="center_horizontal|top"
  22. android:layout_alignParentTop="true"
  23. android:layout_toRightOf="@+id/linearLayout2"/>
  24. <EditText
  25. android:layout_width="200dp"
  26. android:layout_height="wrap_content"
  27. android:inputType="textPersonName"
  28. android:text=""
  29. android:id="@+id/editText1"
  30. android:layout_gravity="center_horizontal|top"
  31. android:layout_alignTop="@+id/linearLayout2"
  32. android:layout_alignParentRight="true"/>
  33. </LinearLayout>
  34. <LinearLayout
  35. android:layout_width="wrap_content"
  36. android:layout_height="wrap_content"
  37. android:layout_marginTop="80dp"
  38. android:orientation="horizontal" android:id="@+id/linearLayout">
  39. <TextView
  40. android:layout_width="wrap_content"
  41. android:layout_height="wrap_content"
  42. android:textAppearance="?android:attr/textAppearanceLarge"
  43. android:text="word"
  44. android:id="@+id/textView"
  45. android:layout_gravity="center_horizontal|top"
  46. android:layout_alignParentTop="true"
  47. android:layout_toRightOf="@+id/linearLayout2"/>
  48. <EditText
  49. android:layout_width="200dp"
  50. android:layout_height="wrap_content"
  51. android:inputType=""
  52. android:text=""
  53. android:id="@+id/editText2"
  54. android:layout_marginLeft="40dp" android:layout_gravity="center_horizontal|top"
  55. android:layout_alignTop="@+id/linearLayout2"
  56. android:layout_alignParentRight="true"/>
  57. </LinearLayout>
  58. <Button
  59. android:layout_width="wrap_content"
  60. android:layout_height="wrap_content"
  61. android:text="Register"
  62. android:id="@+id/button"
  63. android:layout_below="@+id/linearLayout"
  64. android:layout_centerHorizontal="true"
  65. android:layout_marginTop="31dp"/>
  66. >
  67. </RelativeLayout>
Step 3
  1. package com.edittextvalidation;
  2. import android.os.Bundle;
  3. import android.app.Activity;
  4. import android.view.Menu;
  5. import android.view.View;
  6. import android.widget.Button;
  7. import android.widget.EditText;
  8. import android.widget.TextView;
  9. import android.widget.Toast;
  10. public class MainActivity extends Activity {
  11. EditText NameEditText,editTextPhoneNumber,wordEditText;
  12. TextView textViewName,textViewAge,textViewword;
  13. Button RegistrationButton;
  14. @Override
  15. protected void onCreate(Bundle savedInstanceState) {
  16. super.onCreate(savedInstanceState);
  17. setContentView(R.layout.activity_main);
  18. RegistrationButton=(Button)findViewById(R.id.button);
  19. NameEditText=(EditText)findViewById(R.id.editText1);
  20. wordEditText=(EditText)findViewById(R.id.editText2);
  21. RegistrationButton.setOnClickListener(new View.OnClickListener() {
  22. @Override
  23. public void onClick(View view) {
  24. final String Name=NameEditText.getText().toString();
  25. final String word=wordEditText.getText().toString();
  26. if(Name.length()==0)
  27. {
  28. NameEditText.requestFocus();
  29. NameEditText.setError("FIELD CANNOT BE EMPTY");
  30. }
  31. else if(!Name.matches("[a-zA-Z ]+"))
  32. {
  33. NameEditText.requestFocus();
  34. NameEditText.setError("ENTER ONLY ALPHABETICAL CHARACTER");
  35. }
  36. else if(word.length()==0)
  37. {
  38. wordEditText.requestFocus();
  39. wordEditText.setError("FIELD CANNOT BE EMPTY");
  40. }
  41. else
  42. {
  43. Toast.makeText(MainActivity.this,"Validation Successful",Toast.LENGTH_LONG).show();
  44. }
  45. }
  46. });
  47. }
  48. }
Step 4
When we entered no value for the person's name:
3.jpg
Step 5
When we entered no value for the word:
4.jpg
Step 6
When we entered a numeric value:
2.jpg
 Step 7
When we entered a valid value:
6.jpg