12、json、GridView、缓存

public class PhotosData {
	public int retcode;
	public PhotosInfo data;
	public class PhotosInfo {
		public String title;
		public ArrayList<PhotoInfo> news;
	}
	public class PhotoInfo {
		public String id;
		public String listimage;
		public String pubdate;
		public String title;
		public String type;
		public String url;
	}
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical" >
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:background="@drawable/pic_list_item_bg"
        android:gravity="center"
        android:orientation="vertical" >
        <ImageView
            android:id="@+id/iv_pic"
            android:layout_width="match_parent"
            android:layout_height="180dp"
            android:scaleType="centerCrop"
            android:src="@drawable/news_pic_default" />
        <TextView
            android:id="@+id/tv_title"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:padding="10dp"
            android:text="标题"
            android:singleLine="true"
            android:textColor="#000"
            android:textSize="22sp" />
    </LinearLayout>
</LinearLayout>

	public static final String PHOTOS_URL = SERVER_URL
			+ "/photos/photos_1.json";// 获取组图信息的接口

public class PhotoMenuDetailPager extends BaseMenuDetailPager {
	private ListView lvPhoto;
	private GridView gvPhoto;
	private ArrayList<PhotoInfo> mPhotoList;
	private PhotoAdapter mAdapter;
	private ImageButton btnPhoto;
	public PhotoMenuDetailPager(Activity activity, ImageButton btnPhoto) {	super(activity);
		this.btnPhoto = btnPhoto;
//这样就把imagebutton传了过来，好方法。在构造函数里传
		btnPhoto.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				changeDisplay();
			}
		});
	}
	@Override
	public View initViews() {
		View view = View.inflate(mActivity, R.layout.menu_photo_pager, null);
		lvPhoto = (ListView) view.findViewById(R.id.lv_photo);
		gvPhoto = (GridView) view.findViewById(R.id.gv_photo);
		return view;
	}
	@Override
	public void initData() {
		String cache = CacheUtils
				.getCache(GlobalContants.PHOTOS_URL, mActivity);
		if (!TextUtils.isEmpty(cache)) {
		}
		getDataFromServer();
	}
	private void getDataFromServer() {
		HttpUtils utils = new HttpUtils();
		utils.send(HttpMethod.GET, GlobalContants.PHOTOS_URL,
				new RequestCallBack<String>() {
					@Override
					public void onSuccess(ResponseInfo<String> responseInfo) {
						String result = (String) responseInfo.result;
						parseData(result);
						// 设置缓存
						CacheUtils.setCache(GlobalContants.PHOTOS_URL, result,
								mActivity);
					}
					@Override
					public void onFailure(HttpException error, String msg) {
						Toast.makeText(mActivity, msg, Toast.LENGTH_SHORT)
								.show();
						error.printStackTrace();
					}
				});
	}
	protected void parseData(String result) {
		Gson gson = new Gson();
		PhotosData data = gson.fromJson(result, PhotosData.class);
		mPhotoList = data.data.news;// 获取组图列表集合
		if (mPhotoList != null) {
			mAdapter = new PhotoAdapter();
			lvPhoto.setAdapter(mAdapter);
			gvPhoto.setAdapter(mAdapter);
		}
	}
	class PhotoAdapter extends BaseAdapter {
		private BitmapUtils utils;
		public PhotoAdapter() {
			utils = new BitmapUtils(mActivity);
			utils.configDefaultLoadingImage(R.drawable.news_pic_default);
		}
		@Override
		public int getCount() {
			return mPhotoList.size();
		}
		@Override
		public PhotoInfo getItem(int position) {
			return mPhotoList.get(position);
		}
		@Override
		public long getItemId(int position) {
			return position;
		}
		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			ViewHolder holder;
			if (convertView == null) {
				convertView = View.inflate(mActivity, R.layout.list_photo_item,
						null);
				holder = new ViewHolder();
				holder.tvTitle = (TextView) convertView
						.findViewById(R.id.tv_title);
				holder.ivPic = (ImageView) convertView
						.findViewById(R.id.iv_pic);
				convertView.setTag(holder);
			} else {
				holder = (ViewHolder) convertView.getTag();
			}
			PhotoInfo item = getItem(position);
			holder.tvTitle.setText(item.title);
			utils.display(holder.ivPic, item.listimage);
			return convertView;
		}
	}
	static class ViewHolder {
		public TextView tvTitle;
		public ImageView ivPic;
	}
	private boolean isListDisplay = true;// 是否是列表展示
	/**
	 * 切换展现方式
	 */
	private void changeDisplay() {
		if (isListDisplay) {
			isListDisplay = false;
			lvPhoto.setVisibility(View.GONE);
			gvPhoto.setVisibility(View.VISIBLE);
			btnPhoto.setImageResource(R.drawable.icon_pic_list_type);
		} else {
			isListDisplay = true;
			lvPhoto.setVisibility(View.VISIBLE);
			gvPhoto.setVisibility(View.GONE);
			btnPhoto.setImageResource(R.drawable.icon_pic_grid_type);
		}
	}
}

    <ImageButton
            android:id="@+id/btn_photo"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:layout_marginRight="5dp"
            android:background="@null"
            android:src="@drawable/icon_pic_grid_type"
            android:visibility="gone" />

	if (pager instanceof PhotoMenuDetailPager) {
			btnPhoto.setVisibility(View.VISIBLE);
		} else {
			btnPhoto.setVisibility(View.GONE);
		}