画廊布局（ImageSwitcher与Gallery）

//安卓开发之画廊布局（使用系统自带的ImageSwitcher与Gallery实现）

public class MainActivity extends Activity implements ViewFactory {
private Gallery gallery = null;
private ImageSwitcher imageSwitcher = null;
int[] imageIDs = { R.drawable.p1, R.drawable.p2, R.drawable.p3,
R.drawable.p4, R.drawable.p5, R.drawable.p6, R.drawable.p7,
R.drawable.p8 };


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);


imageSwitcher = (ImageSwitcher) findViewById(R.id.imageSwitcher);
// 设置ImageSwitcher组件的工厂对象
imageSwitcher.setFactory(this);
// // 设置ImageSwitcher组件显示图像的动画效果
imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this,
android.R.anim.fade_in));
imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this,
android.R.anim.fade_out));


gallery = (Gallery) findViewById(R.id.gallery);
ImageViewAdapter adapter = new ImageViewAdapter(MainActivity.this,
imageIDs);
Log.i("MainActivity", "123.....0");
gallery.setAdapter(adapter);
Log.i("MainActivity", "123.....1");
gallery.setOnItemSelectedListener(new OnItemSelectedListener() {


public void onItemSelected(AdapterView<?> parent, View view,
int position, long id) {
// 选中Gallery中某个图像时，在ImageSwitcher组件中放大显示该图像
imageSwitcher.setImageResource(imageIDs[position
% imageIDs.length]);
}


public void onNothingSelected(AdapterView<?> arg0) {


}


});


gallery.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Log.i("ljq", "parent=" + parent.getClass().getName()); // Gallery
Log.i("ljq", "view=" + view.getClass().getName()); // ImageView
Log.i("ljq", "position=" + position); // 1
Log.i("ljq", "id=" + id);// 1
Gallery gl = (Gallery) parent;
ImageView iv = (ImageView) view;
}
});


}
//
// @Override
public View makeView() {
ImageView imageView = new ImageView(this);
imageView.setBackgroundColor(0xFF000000);
imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
Log.i("MainActivity", "123.....2");
imageView.setLayoutParams(new ImageSwitcher.LayoutParams(
LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
Log.i("MainActivity", "123.....3");
return imageView;

}

}

//ImageViewAdapter类代码如下：

package com.example.agallerylayout;


import android.content.Context;
import android.content.res.TypedArray;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;


public class ImageViewAdapter extends BaseAdapter {
private int[] imageIDs=null;
   private Context context=null;
  
   public ImageViewAdapter(Context context, int[] imageIDs) {
       this.context=context;
       this.imageIDs=imageIDs;
      
   }


@Override
public int getCount() {
// TODO Auto-generated method stub
return Integer.MAX_VALUE;
}


@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return imageIDs[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 iv = new ImageView(context);
        //优化二，通过取余来循环取得imageIDs数组中的图像资源ID，取余可以大大较少资源的浪费
        iv.setImageResource(imageIDs[position%imageIDs.length]);
        iv.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
       // Log.i("MainActivity", "123.....4");
      //  iv.setLayoutParams(new LinearLayout.LayoutParams(100,100));//把图片缩小原来的60%
       // Log.i("MainActivity", "123.....5");
      //  iv.setBackgroundResource(_mGalleryItemBackground);
        return iv;


    }


}

//布局文件代码如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" 
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <!-- android:unselectedAlpha: 设置未选中的条目的透明度(Alpha)。该值必须是float类型，比如：“1.2”。 -->
    <Gallery android:layout_width="fill_parent"
        android:layout_height="wrap_content" 
        android:spacing="10dip" 
        android:background="@drawable/android_layout_bg"
        android:unselectedAlpha="1.2"
        android:id="@+id/gallery"
        android:layout_marginTop="30dp"/>
    <ImageSwitcher android:id="@+id/imageSwitcher"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="30dp" />
</LinearLayout>