Android开发案例 设置背景图片轮播

点击按钮实现图片轮播效果

实践案例：

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"
    tools:context=".Main2Activity"
    android:orientation="vertical"
    android:gravity="center">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="350dp">

        <android.support.v7.widget.AppCompatImageView
            android:id="@+id/img1"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:src="@mipmap/img1" />

        <android.support.v7.widget.AppCompatImageView
            android:id="@+id/img2"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:src="@mipmap/img2" />

        <android.support.v7.widget.AppCompatImageView
            android:id="@+id/img3"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:src="@mipmap/img3" />
    </LinearLayout>

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

        <Button
            android:id="@+id/button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="切换图片" />

        <Button
            android:id="@+id/button2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="返回主页" />

    </LinearLayout>

</LinearLayout>

Java

package com.example.administrator.demo2;

import android.content.Intent;
import android.media.Image;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

public class Main2Activity extends AppCompatActivity {
    //定义所有的轮播图片
    int[] image = new int[]{
            R.mipmap.img1,
            R.mipmap.img2,
            R.mipmap.img3
    };
    //定义初始下标为0
    int Index = 0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        //获取ImageView
        final ImageView img = (ImageView) findViewById(R.id.img1);
        img.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (Index>=2){
                    Index=-1;
                }
                //改变ImageView中的Src属性值
                img.setImageResource(image[++Index]);
            }
        });

        Button button =  (Button) findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (Index>=2)
                    Index=-1;
                //改变ImageView中的Src属性值
                img.setImageResource(image[++Index]);
            }
        });

        Button ubt1 = (Button) findViewById(R.id.button2);
        ubt1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent it = new Intent();
                it.setClass(Main2Activity.this,MainActivity.class);
                startActivity(it);
            }
        });

    }
}