Android图标/图像设置模式可进行多种选择

Question

What pattern do I have to use, if I have ListView in which ImageView and like 500 different icons that could be set on that ImageView . Should I just write If/Switch statement, or there is another way/pattern to do it?. Thanks in advance!

Answer 1

Where are these icons that you want to set? you are getting them from server or they are stored locally in your application file? or they are from user phone gallery?

Here is the code you want for your adapter:

public class MyAdapter extends BaseAdapter {
    private Context mContext;
    private LayoutInflater mInflater;
    private ArrayList<String> mIconNames;

    public MyAdapter(Context context) {
        mContext = context;
        mIconNames = getIconNames();
        mInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

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

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

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // Get view for row item
        View rowView = mInflater.inflate(R.layout.your_layout, parent, false);
        ImageView thumbnailImageView =
                (ImageView) rowView.findViewById(R.id.your_image_view_id);
        Picasso.with(mContext).load(mIconNames.get(position)).placeholder(R.mipmap.ic_launcher).into(thumbnailImageView);
        return rowView;
    }

    //this method builds your icon names
    private ArrayList<String> getIconNames() {
        ArrayList<String> iconNames = new ArrayList<>();
        int numberOfIcons = 99;
        String iconBaseName = "icon";
        for (int i = 1; i < numberOfIcons; i++) {
            iconNames.add(iconBaseName + i);
        }

        return iconNames;
    } 

}

Answer 2

Let me assume that you know what icon(I mean the name of icon) to be loaded into the imageView and those icons are available in your drawable resource folder. In this case

@Override
public void onBindViewHolder(final RecyclerAdapter.ViewHolder holder, int position) {
    DataItem dataItem = dataList.get(holder.getAdapterPosistion());
    try {
        int resID = activityContext.getResources().getIdentifier(dataItem.getIconName() , "drawable"/**resource folder name*/, activityContext.getPackageName());
        holder.imageView.setBackgroundResource(resID);
    } catch (Exception e) {
        throw new RuntimeException("Error getting Resource ID.", e)
    }
}