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;	}}

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent" >    <ListView        android:id="@+id/lv_photo"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:cacheColorHint="#fff"        android:divider="@null" />    <GridView        android:id="@+id/gv_photo"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:numColumns="2"        android:visibility="gone" /></FrameLayout>

<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);		}