안드로이드 수업 2일차 (버튼 누르면 사진 랜덤으로 출력)

- 버튼 누르면 사진 랜덤으로 출력하기 

 

 

<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"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/btnTest"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Button" />

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <ImageView
            android:id="@+id/imageView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:visibility="invisible"
            app:srcCompat="@drawable/a" />

        <ImageView
            android:id="@+id/imageView2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:visibility="invisible"
            app:srcCompat="@drawable/b" />

        <ImageView
            android:id="@+id/imageView3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:visibility="invisible"
            app:srcCompat="@drawable/c" />

        <ImageView
            android:id="@+id/imageView4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:visibility="invisible"
            app:srcCompat="@drawable/d" />
    </FrameLayout>

</LinearLayout>

 

<MainActivity.java>

package com.example.imageviewapp;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import java.util.Random;

public class MainActivity extends AppCompatActivity {

    Button btnTest;
    ImageView imageView;
    ImageView imageView2;
    ImageView imageView3;
    ImageView imageView4;
    int index = 0;
    Random random = new Random();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        imageView = findViewById(R.id.imageView);
        imageView2 = findViewById(R.id.imageView2);
        imageView3 = findViewById(R.id.imageView3);
        imageView4 = findViewById(R.id.imageView4);
        btnTest = findViewById(R.id.btnTest);

        btnTest.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                index = random.nextInt(4);

                switch(index){
                    case 0:
                        imageView.setVisibility(View.VISIBLE);
                        imageView2.setVisibility(View.INVISIBLE);
                        imageView3.setVisibility(View.INVISIBLE);
                        imageView4.setVisibility(View.INVISIBLE);
                        break;
                    case 1:
                        imageView2.setVisibility(View.VISIBLE);
                        imageView.setVisibility(View.INVISIBLE);
                        imageView3.setVisibility(View.INVISIBLE);
                        imageView4.setVisibility(View.INVISIBLE);
                        break;
                    case 2:
                        imageView3.setVisibility(View.VISIBLE);
                        imageView2.setVisibility(View.INVISIBLE);
                        imageView.setVisibility(View.INVISIBLE);
                        imageView4.setVisibility(View.INVISIBLE);
                        break;
                    case 3:
                        imageView4.setVisibility(View.VISIBLE);
                        imageView2.setVisibility(View.INVISIBLE);
                        imageView3.setVisibility(View.INVISIBLE);
                        imageView.setVisibility(View.INVISIBLE);
                        break;
                }
            }
        });
    }
}