【Android Demo】图片之画廊效果(Gallery Switcher)

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent" android:layout_height="fill_parent">
    <ImageSwitcher android:id="@+id/imageSwitcher"
        android:layout_width="wrap_content" android:layout_height="wrap_content"
        android:layout_centerInParent="true" />

    <Gallery android:id="@+id/gallery" android:background="#55000000"
        android:layout_width="fill_parent" android:layout_height="wrap_content"
        android:layout_alignParentBottom="true" android:spacing="10dp" />
</RelativeLayout>

package wei.ye.g1;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;

public class Hualang extends Activity {
    // 显示图片的资源
    private static int[] images = { R.drawable.baos, R.drawable.caoc,
            R.drawable.chenyj, R.drawable.chenyy, R.drawable.gouj,
            R.drawable.guany, R.drawable.hanx, R.drawable.lp, R.drawable.liub,
            R.drawable.qinq, R.drawable.tiemz, R.drawable.wus,
            R.drawable.xiangy, R.drawable.yuef, R.drawable.zhaoky,
            R.drawable.zhugl, R.drawable.xis, R.drawable.yingz };
    Gallery gallery;
    ImageSwitcher is;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.hualang);
        setTitle("这是Gallery和ImageSwitcher的效果");
        gallery = (Gallery) findViewById(R.id.gallery);
        is = (ImageSwitcher) findViewById(R.id.imageSwitcher);
        gallery.setAdapter(new ImageAdapter(this));
        // 让选定的图片在中心显示
        gallery.setSelection(images.length / 2);
        // 为Gallery绑定监听器；
        gallery.setOnItemSelectedListener(new OnItemSelectedListener() {
            public void onItemSelected(AdapterView<?> parent, View view,
                    int position, long id) {
                // 当在Gallery中选定一张图片是 ImageSwitcher同步显示同一张
                // position%images.length 为了让图片循环显示
                is.setImageResource(images[position % images.length]);

            }

            public void onNothingSelected(AdapterView<?> parent) {

            }
        });

        is.setFactory(new ImageFactory(this));

    }

    private class ImageAdapter extends BaseAdapter {
        private Context context;

        public ImageAdapter(Context context) {
            this.context = context;
        }

        // 可以return images.lenght(),在这里返回Integer.MAX_VALUE
        // 是为了使图片循环显示
        public int getCount() {
            return Integer.MAX_VALUE;
        }

        public Object getItem(int position) {
            return null;
        }

        public long getItemId(int position) {
            return 0;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            ImageView iv = new ImageView(context);
            iv.setImageResource(images[position % images.length]);
            iv.setLayoutParams(new Gallery.LayoutParams(90, 90));
            iv.setAdjustViewBounds(true);
            return iv;
        }
    }

    private class ImageFactory implements ViewFactory {
        private Context context;

        public ImageFactory(Context context) {
            this.context = context;
        }

        public View makeView() {
            ImageView iv = new ImageView(context);
            iv.setLayoutParams(new ImageSwitcher.LayoutParams(200, 200));
            return iv;
        }
    }
}