Android中Gallery和ImageSwitcher的使用

效果如下：

布局文件activity_main.xml如下：

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <ImageSwitcher
        android:id="@+id/imageSwitcher"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="2"
        android:paddingTop="30px" >
    </ImageSwitcher>

    <Gallery
        android:id="@+id/gallery1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:spacing="5px"
        android:unselectedAlpha="0.6" />

</RelativeLayout>

MainActivity.java代码如下：

import android.app.ActionBar.LayoutParams;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
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.ViewSwitcher.ViewFactory;

public class MainActivity extends Activity {

    private int imageId[] = new int[] { R.drawable.a, R.drawable.b,
            R.drawable.c, R.drawable.d, R.drawable.e, R.drawable.f,
            R.drawable.g, R.drawable.h, R.drawable.i, R.drawable.j,
            R.drawable.k };

    private ImageSwitcher imageSwitcher;
    private Gallery gallery;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        imageSwitcher = (ImageSwitcher) this.findViewById(R.id.imageSwitcher);
        gallery = (Gallery) this.findViewById(R.id.gallery1);

        // 设置动画效果
        imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this,
                android.R.anim.fade_in));
        imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this,
                android.R.anim.fade_out));

        imageSwitcher.setFactory(new ViewFactory() {

            @Override
            public View makeView() {
                ImageView imageView = new ImageView(MainActivity.this);
                imageView.setScaleType(ImageView.ScaleType.FIT_CENTER); // 设置保持纵横比居中
                imageView.setLayoutParams(new ImageSwitcher.LayoutParams(
                        LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

                return imageView;
            }
        });

        GalleryAdapter adapter = new GalleryAdapter(MainActivity.this,imageId);
        gallery.setAdapter(adapter);
        gallery.setSelection(imageId.length / 2);
        gallery.setOnItemSelectedListener(new OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView<?> parent, View view,int position, long id) {
                imageSwitcher.setImageResource(imageId[position]);
            }

            @Override
            public void onNothingSelected(AdapterView<?> arg0) {

            }
        });
    }
}

其中需要的一个适配器：

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

public class GalleryAdapter extends BaseAdapter {

    private int[] imageId;

    private Context mContext;

    /**
     * 穿入上下文和图片资源数组
     * @param mContext
     * @param imageId
     */
    public GalleryAdapter(Context mContext, int[] imageId) {
        this.mContext = mContext;
        this.imageId = imageId;
    }

    @Override
    public int getCount() {
        return imageId.length;
    }

    @Override
    public Object getItem(int position) {
        return imageId[position];
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView1;
        if (convertView == null) {
            imageView1 = new ImageView(mContext);
            imageView1.setScaleType(ImageView.ScaleType.FIT_XY);
            imageView1.setLayoutParams(new Gallery.LayoutParams(180, 135));
            TypedArray typedArray = mContext
                    .obtainStyledAttributes(R.styleable.Gallery);
            imageView1.setBackgroundResource(typedArray.getResourceId(
                    R.styleable.Gallery_android_galleryItemBackground, 0));
            imageView1.setPadding(5, 0, 5, 0); // 设置ImageView的内边距
        } else {
            imageView1 = (ImageView) convertView;
        }
        imageView1.setImageResource(imageId[position]); // 为ImageView设置要显示的图片
        return imageView1; // 返回ImageView
    }

}

到此 OK！