Gallery 画廊效果

 
1.首先创建实现OnItemSelectedListener,ViewFactory类。
2.创建ImageAdapter类。
3.Activity类。
MyOnItemSelectedListener:当Gallery被选择的时候，把被选择的图片放到ImageSwitch里面去。
MyImageAdapter:实现Gallery显示的图片。
ViewFactory:ImageSwitch的显示工厂。

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />
    <Gallery
        android:id="@+id/gallery1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" 
        android:layout_marginTop="30dp"/>

    <ImageSwitcher android:id="@+id/imageswitcher1"  
     android:layout_height="fill_parent"  
    android:layout_width="fill_parent"  
    android:layout_alignParentTop="true"  
    android:layout_alignParentLeft="true">  
    </ImageSwitcher>
</LinearLayout>

MyOnItemSelectedListener.java

-----------------------

package com.gallery;

import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.ImageSwitcher;

public class MyOnItemSelectedListener implements OnItemSelectedListener{
  private ImageSwitcher imageswitcher1;
  private int[] images;

  public MyOnItemSelectedListener(ImageSwitcher imageswitcher1,int[] images){
    this.imageswitcher1 = imageswitcher1;
    this.images = images;

  }
  @Override
  public void onItemSelected(AdapterView<?> arg0, View arg1, int position,
      long arg3) {
    // 第2点改进，通过取余来循环取得images数组中的图像资源ID
    imageswitcher1.setImageResource(images[position % images.length]);  

  }

  @Override
  public void onNothingSelected(AdapterView<?> arg0) {
    // TODO Auto-generated method stub

  }
}

MyImageAdapter.java

----------------------

package com.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;

public class MyImageAdapter extends BaseAdapter {

  public Context context;
  private int[] images;
  public MyImageAdapter(Context context,int[]images){
    this.context = context;
    this.images = images;
  }
  @Override
  public int getCount() {
    //获得图片的总数，这里设定为最大值，是为了模拟循环显示
    return Integer.MAX_VALUE;
  }

  @Override
  public Object getItem(int arg0) {
    return null;
  }

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

  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
    ImageView imageView = new ImageView(context);
    // 第2点改进，通过取余来循环取得images数组中的图像资源ID
    imageView.setImageResource(images[position % images.length]);
    imageView.setScaleType(ImageView.ScaleType.FIT_XY);
    imageView.setLayoutParams(new Gallery.LayoutParams(100, 100));
    //imageView.setBackgroundResource(mGalleryItemBackground);
    return imageView;
  }

}

ViewFactory类

-----------------------

package com.gallery;

import android.app.ActionBar.LayoutParams;
import android.content.Context;
import android.view.View;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;

public class MyViewFactory implements ViewFactory {

  private Context context;

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

}

Activity类

---------------------------

package com.gallery;

import android.app.Activity;
import android.os.Bundle;
import android.view.animation.AnimationUtils;
import android.widget.Gallery;
import android.widget.ImageSwitcher;

public class MyGalleryActivity extends Activity{
    private Gallery gallery1;
    private ImageSwitcher imageswitcher1;
    private int[] images = new int[] { R.drawable.android0001, R.drawable.android0002, R.drawable.android0003, R.drawable.android0004, R.drawable.android0005, R.drawable.android0006, R.drawable.android0007, R.drawable.android0008 };

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        imageswitcher1 = (ImageSwitcher)findViewById(R.id.imageswitcher1);
        imageswitcher1.setFactory(new MyViewFactory(MyGalleryActivity.this));
        imageswitcher1.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));  
        imageswitcher1.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out)); 

        gallery1 = (Gallery)findViewById(R.id.gallery1);
        gallery1.setAdapter(new MyImageAdapter(this,images));
        gallery1.setOnItemSelectedListener(new MyOnItemSelectedListener(imageswitcher1,images));
    }

}