2022.09.20 Android Studio

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    android:gravity="center"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:text="ToastMessage"
        android:textSize="20dp"
        android:layout_height="wrap_content"/>

    <Button
        android:id="@+id/dialog"
        android:layout_width="wrap_content"
        android:text="대화상자"
        android:textSize="20dp"
        android:layout_height="wrap_content"/>

    <Button
        android:id="@+id/version"
        android:text="version"
        android:textSize="20dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <TextView
        android:id="@+id/result"
        android:layout_marginRight="10dp"
        android:background="#eea"
        android:layout_width="match_parent"
        android:layout_height="50dp"/>

</LinearLayout>

MainActivity.java

package com.example.myapplication;

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.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
Button button, dialog, version;
TextView result;
String list[] =new String[]{"누가","젤리빈","키캣",""};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button = findViewById(R.id.button);
        result = findViewById(R.id.result);
        version = findViewById(R.id.version);
        version.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                // 대화상자 변수 dlg 생성하기
                AlertDialog.Builder dlg = new AlertDialog.Builder(MainActivity.this);
                dlg.setTitle("version>>");
                dlg.setItems(list, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        //화면 result 위젯에 뿌리는 소스 작성하시오
                        result.setText("선택항목:" + list[i]+"이군요");
                        result.setTextSize(30);
                        result.setTextColor(Color.RED);
                        Toast.makeText(MainActivity.this,
                                "선택한 항목", Toast.LENGTH_LONG).show();
                    }
                });
                dlg.show();
            }
        });




        dialog = findViewById(R.id.dialog);

        dialog.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                // 대화상자 만들기 소스
                AlertDialog.Builder dlg = new AlertDialog.Builder(MainActivity.this);
                final String name[]={"hong"};
                dlg.setTitle("대화상자 만들기");
                dlg.setIcon(R.mipmap.ic_launcher);
                dlg.setMessage("원하는 정보출력");
                dlg.setPositiveButton("ok", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        Toast.makeText(MainActivity.this, "ok가 선택되었어요",
                                    Toast.LENGTH_LONG).show();
                    }
                });

                dlg.setNegativeButton("cancle", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        Toast.makeText(MainActivity.this, "cancle이 선택되었어요",
                                Toast.LENGTH_LONG).show();
                    }
                });
                dlg.show();


            }
        });


        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(getApplicationContext(),
                        "   눌렀죠?", Toast.LENGTH_LONG).show();
            }
        });

    }
}