android ImageSwitcher

<?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/switcher"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true" />

    <Gallery
        android:id="@+id/gallery"
        android:layout_width="fill_parent"
        android:layout_height="60dp"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:background="#ff00ff"
        android:gravity="center_vertical"
        android:spacing="16dp" />

</RelativeLayout>

package com.example.yanlei.mytk;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;

import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.Gallery.LayoutParams;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher;


public class MainActivity extends AppCompatActivity implements ViewSwitcher.ViewFactory {


    private ImageSwitcher mSwitcher;
    private Gallery gallery;
    private Context mContext;

    private Integer[] mImageIds = {
            R.drawable.sample_0, R.drawable.sample_1, R.drawable.sample_2,
            R.drawable.sample_3, R.drawable.sample_4, R.drawable.sample_5,
            R.drawable.sample_6, R.drawable.sample_7, R.drawable.sample_8,
            R.drawable.sample_9, R.drawable.sample_10, R.drawable.sample_11};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setTitle("瀏覽圖片");
        mSwitcher = (ImageSwitcher) findViewById(R.id.switcher);
        gallery = (Gallery) findViewById(R.id.gallery);

        mSwitcher.setFactory(this);
        mSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
        mSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));

        gallery.setAdapter(new ImageAdapter(this));
        gallery.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

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

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

            }

        });
    }

    public class ImageAdapter extends BaseAdapter {

        public ImageAdapter(Context context) {
            mContext = context;
        }

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

        @Override
        public Object getItem(int position) {

            return position;
        }

        @Override
        public long getItemId(int position) {

            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            ImageView i = new ImageView(mContext);
            i.setImageResource(mImageIds[position]);
            i.setAdjustViewBounds(true);
            i.setLayoutParams(new Gallery.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
            i.setBackgroundResource(R.drawable.picture_frame);
            return i;
        }

    }

    @Override
    public View makeView() {
        ImageView i = new ImageView(this);
        i.setBackgroundColor(0xFF000000);
        i.setScaleType(ImageView.ScaleType.FIT_CENTER);
        i.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
        return i;
    }
}