Android_Gallery

xml布局

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.example.android.gallery.MainActivity" >

    <Gallery 
        android:id="@+id/gallery"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
    <ImageSwitcher 
        android:id="@+id/is"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
       />
</LinearLayout>

自定义适配器：

package com.example.android.gallery;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;

public class MyAdapter extends BaseAdapter {
    private int[] res;
    private Context context;
    
    public MyAdapter(int[] res, Context context) {    
        this.res = res;
        this.context = context;
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return Integer.MAX_VALUE;//设置数量为整型的最大值，使图片循环播放
    }

    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return res[position];
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView image = new ImageView(context);
        image.setBackgroundResource(res[position%res.length]);//设置背景图片无限循环
        image.setLayoutParams(new Gallery.LayoutParams(400, 300));//设置缩略图的大小
        image.setScaleType(ScaleType.FIT_XY);//设置按比例缩放
        return image;
    }

}

MainActivity类：

package com.example.android.gallery;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.Gallery;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;
import android.widget.ViewSwitcher.ViewFactory;
/**
 * ImageSwitcher:和ImageView的功能类似，都适用与显示图片，
 *         区别：ImageSwitcher的效果更炫，它可以指定图片切换的动画效果
 * 
 * ImageSwticher可以粗略理解为ImageView的选择器，需要设置ViewFactory，
 * 一般来说，会把ViewFactory的makeView()方法，返回ImageView。
 * @author Administrator
 *
 */
public class MainActivity extends Activity implements ViewFactory,OnItemSelectedListener{
    //准备数据源
    private int[] res = {R.drawable.item1,R.drawable.item2,R.drawable.item3,R.drawable.item4,
                        R.drawable.item5,R.drawable.item6,R.drawable.item7,R.drawable.item8,
                        R.drawable.item9,R.drawable.item10,R.drawable.item11,R.drawable.item12};
    private Gallery gallery;
    private ImageSwitcher is;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        gallery = (Gallery) findViewById(R.id.gallery);
        //自定义适配器
        MyAdapter adapter = new MyAdapter(res,this);
        //为gallery设置适配器
        gallery.setAdapter(adapter);
        //为gallery设置监听器,用来监听Gallery选中的图片
        gallery.setOnItemSelectedListener(this);
        
        is = (ImageSwitcher) findViewById(R.id.is);
        is.setFactory(this);//为imageSwitcher设置视图工厂
        //为imageSwitcher设置动画效果
        is.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
        is.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));
    }
    @Override
    public View makeView() {
        // TODO Auto-generated method stub
        ImageView image = new ImageView(this);
        image.setScaleType(ScaleType.FIT_CENTER);//使图片按比例缩放并居中
        return image;
    }
    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position,
            long id) {
        // TODO Auto-generated method stub
        is.setBackgroundResource(res[position%res.length]);
    }
    @Override
    public void onNothingSelected(AdapterView<?> parent) {
        // TODO Auto-generated method stub
        
    }
}