Android简单开发之 通用Adapter ViewHolder

我们寻常使用Adapter的方式

public class BusbaseSearchApadter extends SimpleBaseApadter {

	private List<Busbase> busbases = new ArrayList<Busbase>();
	public Context context;
	public void setList(List<Busbase> busbases) {
		this.busbases = busbases;
	}

	public BusbaseSearchApadter(Context context) {
		super(context);
		this.context = context;
	}

	@Override
	public int getCount() {
		return busbases.size();
	}

	@Override
	public Object getItem(int position) {
		return busbases.get(position);
	}

	@Override
	public long getItemId(int position) {
		return position;
	}

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		Busbase busbase = busbases.get(position);
		ViewHolder holder = null;
		if(convertView == null){
			holder = new ViewHolder();
			convertView = LayoutInflater.from(context).inflate(R.layout.hx_item_search_bus, parent, false);
			holder.hx_item_bus_search_image = (ImageView)convertView.findViewById(R.id.hx_item_bus_search_image);
			holder.hx_item_bus_search_name = (TextView)convertView.findViewById(R.id.hx_item_bus_search_name);
			holder.hx_item_bus_search_mobile = (TextView)convertView.findViewById(R.id.hx_item_bus_search_mobile);
			convertView.setTag(holder);
		}else{
			holder = (ViewHolder)convertView .getTag();
		}
		bitmapUtils.display(holder.hx_item_bus_search_image, busbase.getShopLogo());
		holder.hx_item_bus_search_name.setText(busbase.name);
		holder.hx_item_bus_search_mobile.setText(busbase.mobile);
		return convertView;
	}

	class ViewHolder{
		ImageView hx_item_bus_search_image;
		TextView hx_item_bus_search_name;
		TextView hx_item_bus_search_mobile;
	}

能够看出当中  实用的代码仅仅有仅仅有getView  和ViewHolder  可是其它的代码又不得不写，太痛苦 了不得不反复的写无数adapter 和ViewHoder.

我们能够写一个通用的ViewHolder

public class ViewHolder {
	private final SparseArray<View> mViews;
    private int mPosition;
    private View mConvertView;
    protected BitmapUtils bitmapUtils;

    private ViewHolder(Context context, ViewGroup parent, int layoutId,
            int position)
    {
    	bitmapUtils = new BitmapUtils(context);
		bitmapUtils.configDefaultLoadingImage(R.drawable.hx_loodding);
		bitmapUtils.configDefaultLoadFailedImage(R.drawable.hx_loodding);
		bitmapUtils.configDefaultBitmapConfig(Bitmap.Config.RGB_565);
        this.mPosition = position;
        this.mViews = new SparseArray<View>();
        mConvertView = LayoutInflater.from(context).inflate(layoutId, parent,
                false);
        // setTag
        mConvertView.setTag(this);
    }  

    /**
     * 拿到一个ViewHolder对象
     *
     * @param context
     * @param convertView
     * @param parent
     * @param layoutId
     * @param position
     * @return
     */
    public static ViewHolder get(Context context, View convertView,
            ViewGroup parent, int layoutId, int position)
    {
        if (convertView == null)
        {
            return new ViewHolder(context, parent, layoutId, position);
        }
        return (ViewHolder) convertView.getTag();
    }  

    public View getConvertView()
    {
        return mConvertView;
    }  

    /**
     * 通过控件的Id获取对于的控件，假设没有则增加views
     *
     * @param viewId
     * @return
     */
    public <T extends View> T getView(int viewId)
    {
        View view = mViews.get(viewId);
        if (view == null)
        {
            view = mConvertView.findViewById(viewId);
            mViews.put(viewId, view);
        }
        return (T) view;
    }  

    /**
     * 为TextView设置字符串
     *
     * @param viewId
     * @param text
     * @return
     */
    public ViewHolder setText(int viewId, String text)
    {
        TextView view = getView(viewId);
        view.setText(text);
        return this;
    }  

    /**
     * 为ImageView设置图片
     *
     * @param viewId
     * @param drawableId
     * @return
     */
    public ViewHolder setImageResource(int viewId, int drawableId)
    {
        ImageView view = getView(viewId);
        view.setImageResource(drawableId);  

        return this;
    }  

    /**
     * 为ImageView设置图片
     *
     * @param viewId
     * @param drawableId
     * @return
     */
    public ViewHolder setImageBitmap(int viewId, Bitmap bm)
    {
        ImageView view = getView(viewId);
        view.setImageBitmap(bm);
        return this;
    }  

    /**
     * 为ImageView设置图片
     *
     * @param viewId
     * @param drawableId
     * @return
     */
    public ViewHolder setImageByUrl(int viewId, String url)
    {
    	bitmapUtils.display((ImageView) getView(viewId), url);
        return this;
    }  

    public int getPosition()
    {
        return mPosition;
    }

使用一个SparseArray将View存起来

如今Adapter这样写

public abstract class AbstuctBaseApadter<T> extends SimpleBaseApadter {

	protected LayoutInflater mInflater;
	protected Context mContext;
	protected List<T> mDatas;
	protected int mItemLayoutId;
	public AbstuctBaseApadter(Context context) {
		super(context);
	}

    public AbstuctBaseApadter(Context context, List<T> mDatas, int itemLayoutId)
    {
    	this(context);
        this.mContext = context;
        this.mInflater = LayoutInflater.from(mContext);
        this.mDatas = mDatas;
        this.mItemLayoutId = itemLayoutId;
    }  

    public void setList(List<T> mDatas){
    	 this.mDatas = mDatas;
    }

    @Override
    public int getCount()
    {
        return mDatas.size();
    }  

    @Override
    public T getItem(int position)
    {
        return mDatas.get(position);
    }  

    @Override
    public long getItemId(int position)
    {
        return position;
    }  

    @Override
    public View getView(int position, View convertView, ViewGroup parent)
    {
        final ViewHolder viewHolder = getViewHolder(position, convertView,
                parent);
        convert(viewHolder, getItem(position));
        return viewHolder.getConvertView();  

    }  

    public abstract void convert(ViewHolder helper, T item);  

    private ViewHolder getViewHolder(int position, View convertView,
            ViewGroup parent)
    {
        return ViewHolder.get(mContext, convertView, parent, mItemLayoutId,
                position);
    }

如今我们仅仅须要重写 convert方法  看activity里面怎么使用

		AbstuctBaseApadter abstuctBaseApadter = new AbstuctBaseApadter<Map<String,Object>>(activity,list_map,R.layout.hx_money_item) {
			public void convert(ViewHolder helper, Map<String, Object> item) {
				helper.setText(R.id.id_item_1, item.get("time").toString());
				helper.setText(R.id.id_item_3, item.get("sourcename").toString());
			}
		};

直接在activity里面写匿名内部类就能够了

哈哈  打工改成