Android控件系列之相册Gallery&Adapter适配器入门&控件缩放动画入门

<?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"
>
<Gallery
android:id="@+id/gallery"
android:layout_width="fill_parent"
android:layout_height="200px"
>
</Gallery>
</LinearLayout>

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//根据ID寻找到相册
Gallery gallery = (Gallery)this.findViewById(R.id.gallery);
//初始化自定义的图片适配器
ImageAdapter adp = new ImageAdapter(this);
//绑定适配器
gallery.setAdapter(adp);
//监听图片选中事件
gallery.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
//初始化“缩放动画”类的实例，表示从1倍放大到1.5倍，并且放大的中心点是图片的中心点
ScaleAnimation animation = new ScaleAnimation(1, 1.5f, 1, 1.5f,
Animation.RELATIVE_TO_SELF,0.5f,Animation.RELATIVE_TO_SELF,0.5f);
//从1倍到1.5倍需要1秒钟
animation.setDuration(1000);
//开始执行动画
arg1.startAnimation(animation);
}
});
}
//自定义适配器
public class ImageAdapter extends BaseAdapter{
//该值仅仅为了传递Activity
private Context context;
public ImageAdapter(Context context){
this.context = context;
}
//存放图片ID的数组，每个ID可以被ImageView所调用，从而显示图片
private int[] imageArray = {
R.drawable.p01,
R.drawable.p03,
R.drawable.p04,
R.drawable.p05,
R.drawable.p07,
R.drawable.p09,
R.drawable.p21,
R.drawable.p23,
R.drawable.p33
};
@Override
public int getCount() {
// TODO Auto-generated method stub
//返回数组的总数
return imageArray.length;
}
@Override
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return arg0;
}
@Override
public long getItemId(int arg0) {
// TODO Auto-generated method stub
return arg0;
}
@Override
public View getView(int arg0, View arg1, ViewGroup arg2) {
// TODO Auto-generated method stub
//实现Adapter的核心，即根据给定的数据返回什么样的控件
//您需要返回的是ImageView，因为您要实现的是相册
ImageView view = new ImageView(this.context);
//获取指定索引的图片的ID
int id = imageArray[arg0];
//将ID告诉ImageView,它就能找到图片
view.setImageResource(id);
//对ImageView进行布局
view.setLayoutParams(new Gallery.LayoutParams(120,120));
//设置ImageView的拉升类型，这里采用居中，您可以尝试不同的类型
view.setScaleType(ImageView.ScaleType.FIT_CENTER);
return view;
}
}