Explanation:
Button is a widget under Buttons section which is used to execute specific code.
Example:
XML file:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 |
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <Button android:id="@+id/button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:layout_centerHorizontal="true" android:layout_marginTop="173dp" android:text="Button" android:textStyle="bold"/> </RelativeLayout> |
Java File:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 |
package com.example.android.sampleproject; import android.graphics.Color; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; public class MainActivity extends AppCompatActivity { private Button b1; private int i=0; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); b1=findViewById(R.id.button); b1.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { switch (i) { case 0: b1.setBackgroundColor(Color.BLUE); i=1; break; case 1: b1.setBackgroundColor(Color.RED); i=0; } } }); { } } } |
| Before Click:
|
After First Click:
|
After Second Click:
|
