一个简单的Android画廊实例

[android]代码库

public class GalleryDemo extends Activity {
	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main); /* 透过findViewById取得 */
		Gallery g = (Gallery) findViewById(R.id.mygallery); /* 新增一ImageAdapter并设定给Gallery对象 */
		g.setAdapter(new ImageAdapter(this)); /* 设定一个itemclickListener并Toast被点选图片的位置 */
		g.setOnItemClickListener(new OnItemClickListener() {
			public void onItemClick(AdapterView parent, View v, int position,
					long id) {
				Toast.makeText(
						GalleryDemo.this,
						getString(R.string.my_gallery_text_pre) + position
								+ getString(R.string.my_gallery_text_post),
						Toast.LENGTH_SHORT).show();
			}
		});
	} /* 改写BaseAdapter自定义一ImageAdapter class */

	public class ImageAdapter extends BaseAdapter { /* 宣告变量 */
		int mGalleryItemBackground;
		private Context mContext; /* ImageAdapter的建构子 */

		public ImageAdapter(Context c) {
			mContext = c; /* 使用在res/values/attrs.xml中的定义 * 的Gallery属性. */
			TypedArray a = obtainStyledAttributes(R.styleable.Gallery); /*
																		 * 取得Gallery属性的Index
																		 * id
																		 */
			mGalleryItemBackground = a.getResourceId(
					R.styleable.Gallery_android_galleryItemBackground, 0); /* 让对象的styleable属性能够反复使用 */
			a.recycle();
		} /* 一定要重写的方法getCount,传回图片数目 */

		public int getCount() {
			return myImageIds.length;
		} /* 一定要重写的方法getItem,传回position */

		public Object getItem(int position) {
			return position;
		} /* 一定要重写的方法getItemId,传回position */

		public long getItemId(int position) {
			return position;
		} /* 一定要重写的方法getView,传回一View对象 */

		public View getView(int position, View convertView, ViewGroup parent) { /* 产生ImageView对象 */
			ImageView i = new ImageView(mContext); /* 设定图片给imageView对象 */
			i.setImageResource(myImageIds[position]); /* 重新设定图片的宽高 */
			i.setScaleType(ImageView.ScaleType.FIT_XY); /* 重新设定Layout的宽高 */
			i.setLayoutParams(new Gallery.LayoutParams(136, 88)); /* 设定Gallery背景图 */
			i.setBackgroundResource(mGalleryItemBackground); /* 传回imageView物件 */
			return i;
		} /* 建构一Integer array并取得预加载Drawable的图片id */

		private Integer[] myImageIds = { R.drawable.photo1, R.drawable.photo2,
				R.drawable.photo3, R.drawable.photo4, R.drawable.photo5,
				R.drawable.photo6, };
	}
}