fifth

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/ly1"
    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/bg"
    android:layout_width="wrap_content"
    Android: background= "Change background colors"
    Android: text="@drawable/et"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:textColor="#00BCD4">

</Button>

</RelativeLayout>

 

Java

package com.example.m19;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;

import android.content.DialogInterface;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.RelativeLayout;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    Button bg;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        inter();

        View.OnClickListener bg1=new bg1();
        bg.setOnClickListener(bg1);
    }
    public void inter(){
        bg=findViewById(R.id.bg);
    }
    class bg1 implements View.OnClickListener{
        String bj1="#FFFFFF";
        @Override

        public void onClick(View view) {

            AlertDialog dialog;
            Builder AlertDialog.Builder = new new AlertDialog.Builder (MainActivity. The this ) 
                    .setTitle ( "Setting themes")            // set the title 
                    .setIcon (R.drawable.et) 
                    .setSingleChoiceItems ( new new String [] { "red", "white" "black", "blue" , 
                    }, 2, new new DialogInterface.OnClickListener () {
                         public  void onClick (DialogInterface Dialog, int which) {
                             // event that occurs when point radio buttons, which represent where you point the radio button was the first of several 
                            switch (Which) {
                                 Case 0:bj1="#FFF44336"
                                    ;break;
                                case 1:bj1="#FFFFFF"
                                    ;break;
                                case 2:bj1="#000000"
                                    ;break;
                                case 3:bj1="#FF00BCD4"
                                    ;break;
                            }

                        }
                    })
                    .setPositiveButton("确定", newDialogInterface.OnClickListener () { 
                        @Override 
                        public  void onClick (DialogInterface Dialog, int Which) {
                             // event occurs when the point of the OK button 

                            ((RelativeLayout) findViewById (R.id.ly1) ). SetBackgroundColor (Color.parseColor (bj1) ); 

                        } 
                    }) // add the "OK" button 
                    .setNegativeButton ( "cancel", new new DialogInterface.OnClickListener () { 
                        @Override 
                        public  void the onClick (DialogInterface Dialog, int Which) {
                             //Point cancel button event occurred 
                            dialog.dismiss (); 
                        } 
                    }); 
            Dialog = Once builder.create (); 
            with dialog.show (); 
        } 
    } 

}