ImageSwitcher的简单使用

测试代码：

activity_main.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/MyLayout"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <ImageSwitcher
        android:id="@+id/imageSwitcher"
        android:layout_gravity="center"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/btnPrevious"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:enabled="false"
            android:text="上一张" />

        <Button
            android:id="@+id/btnNext"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:enabled="true"
            android:text="下一张" />
    </LinearLayout>

</LinearLayout>

MainActivity.java：

package com.example.zz;


import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup.LayoutParams;
import android.view.animation.AnimationUtils;
import android.widget.Button;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;

public class MainActivity extends Activity {
    private ImageSwitcher imageSwitcher;
    private Button btnPrevious;
    private Button btnNext;
    private int foot=0;
    private int[] imgRes=new int[]{R.drawable.a,R.drawable.b,R.drawable.c,R.drawable.d,R.drawable.e,};
    
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState); // 生命周期方法
        super.setContentView(R.layout.activity_main); // 设置要使用的布局管理器
    imageSwitcher=(ImageSwitcher)findViewById(R.id.imageSwitcher);
    btnPrevious=(Button)findViewById(R.id.btnPrevious);
    btnNext=(Button)findViewById(R.id.btnNext);
    
    imageSwitcher.setFactory(new ViewFactory() {//设置转化工厂
        
        @Override
        public View makeView() {
            ImageView imageView=new ImageView(MainActivity.this);
            imageView.setBackgroundColor(0xFFFFFFFF);
            imageView.setScaleType(ImageView.ScaleType.CENTER);//居中显示
            imageView.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT));//定义组件
            return imageView;
        }
    });
    imageSwitcher.setImageResource(imgRes[foot++]);//初始化时显示，必须放在工厂后面，否则会报NullPointerException
    imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));//设置动画
    imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));//设置动画
    btnPrevious.setOnClickListener(new OnClickListener() {
        
        public void onClick(View v) {
            MainActivity.this.imageSwitcher.setImageResource(imgRes[foot--]);
            MainActivity.this.checkBtnEnable();
            
        }
    });
    btnNext.setOnClickListener(new OnClickListener() {
        
        public void onClick(View v) {
            MainActivity.this.imageSwitcher.setImageResource(imgRes[foot++]);
            MainActivity.this.checkBtnEnable();
            
        }
    });

    }

    protected void checkBtnEnable() {//判断按钮可用状态
        if(this.foot<this.imgRes.length-1){
            this.btnNext.setEnabled(true);
        }else{
            this.btnNext.setEnabled(false);
        }
        if(this.foot==0){
            this.btnPrevious.setEnabled(false);
        }else {
            this.btnPrevious.setEnabled(true);
        }
        
    }
}