Android ImageView功能的实现

例题2-13

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<!--suppress ALL -->
<LinearLayout xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    android:gravity="center"
    xmlns:android="http://schemas.android.com/apk/res/android">
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">

        <ImageView android:id="@+id/image"
            android:layout_width="355dip"
            android:layout_height="650dip"
            android:src="@drawable/p2"/>
    </LinearLayout>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="fill_parent">
        <Button android:id="@+id/up"
            android:layout_width="150dip"
            android:layout_height="wrap_content"
            android:text="上一张"/>
        <Button android:id="@+id/down"
            android:layout_width="150dip"
            android:layout_height="wrap_content"
            android:text="下一张"/>
    </LinearLayout>
</LinearLayout>

Mainactivity.java代码

package com.example.hello;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.telephony.SmsManager;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.RadioButton;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    Button Button1,Button2;
    int[] images={
            R.drawable.p2, R.drawable.p3, R.drawable.p4, R.drawable.p5,
            R.drawable.p6, R.drawable.p7, R.drawable.p8, R.drawable.p9,
            R.drawable.p10, R.drawable.p11, R.drawable.p12, R.drawable.p1
    };
    ImageView image;
    int index=0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button1 = (Button)findViewById(R.id.up);
        Button2 = (Button)findViewById(R.id.down);
        image = (ImageView)findViewById(R.id.image);
        Button1.setOnClickListener(new mclik());
        Button2.setOnClickListener(new mclik());
    }

    class mclik implements View.OnClickListener{

        @Override
        public void onClick(View v) {
            if(v==Button1){
                if(index>0&&index<images.length){
                    index--;
                    image.setImageResource(images[index]);
                }else {
                    index=images.length-1;
                    image.setImageResource(images[index]);
                }
            }
            if(v==Button2){
                if(index>=0&&index<images.length-1){
                    index++;
                    image.setImageResource(images[index]);
                }else {
                    index=0;
                    image.setImageResource(images[index]);
                }
            }
        }
    }

}