Android Homework01

package com.example.myhomework;
import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.ImageView;import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity {
    private ImageView image;

    //建立圖片型別變數image    private Button button01;

    //建立按鈕型別變數button01    private Button button02;

    //建立按鈕型別變數button02    private TextView tvResult;

  //建立字型別變數tvResult    private int currentImage = 0;

   //建立整數變數currentImagee給定初值為0    int[] images = {R.drawable.image01, R.drawable.image2, R.drawable.image3, R.drawable.image4, R.drawable.image5};   //建立整數陣列images,將圖片陣列路徑傳入,傳入的圖片會以數字型態表示    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);
        image = findViewById(R.id.imageView01); 

        //將圖片1的ID傳入變數image        tvResult = findViewById(R.id.textView); 

        //將字的ID傳入變數image        button01 = findViewById(R.id.button01);

        //將按鈕1的ID傳入變數button01        button01.setOnClickListener(aButtonChangeImageListener);

        //當 button01發生點擊事件時導入aButtonChangeImageListener物件        button02 = findViewById(R.id.button02);

        //將按鈕2的ID傳入變數button02        button02.setOnClickListener(aButtonChangeImageListener2);

        //當 button02發生點擊事件時導入aButtonChangeImageListener2物件    }
    View.OnClickListener aButtonChangeImageListener = new View.OnClickListener() {  //設定aButtonChangeImageListener事件內容        public void onClick(View v) {   //當發生點擊事件時            if (currentImage == 4) {    //如果陣列編號為4-->編號歸0                currentImage = 0;
            } else {                    //否則陣列編號遞增1                currentImage++;            }
            String text = currentImage+1 + "/" + images.length;   //宣告字串text並將currentImage+1和images.length串接            tvResult.setText(text); //設定顯示字串            image.setImageResource(images[currentImage]); //設定顯示圖片        }
    };    View.OnClickListener aButtonChangeImageListener2 = new View.OnClickListener() { //設定aButtonChangeImageListener2事件內容        public void onClick(View v) {
            if (currentImage == 0) {   //如果陣列編號為0-->編號遞減                currentImage = images.length - 1;            } else {
                currentImage--;            }
            String text = currentImage + 1 + "/" + images.length;      //宣告字串text並將currentImage+1和images.length串接            tvResult.setText(text); //設定顯示字串            image.setImageResource(images[currentImage]); //設定顯示圖片        }
    };}