Adapter 超简洁写法

EasyListView

每次用到 ListView 时候都需要写一个Adapter；令人恶心的是需要在getView() 方法中添加一堆代码，无论是维护还是从头开始写都非常不便。该项目能够极大的简化代码，使得代码更加模块化，且只需要三步就可以实现一个 Adapter。
GitHub : https://github.com/jqzhang/EasyListView

实现思路：

1. 根据不同的 viewType 创建 View
2. 绑定（项目中用Buttetknife 实现）
3. 更新View

主要代码：

@Override
public View getView(int position, View convertView, ViewGroup parent) { 
  ViewHolder vh;   
  // 如果view为null 或者 类型不符则重新创建
  if (null == convertView || ((convertView.getTag() != null) && (((ViewHolder) convertView.getTag()).getType() != getItemViewType(position))))    {      
    vh = onCreateViewHolder(parent, position);          
    vh.setType(getItemViewType(position));   
  } else {      
    vh = (ViewHolder) convertView.getTag();   
  }   
  if (null == vh) {      
    return null;   
  }   
  vh.updateView(vh.getConvertView(), getItem(position), position);   
  return vh.getConvertView();
}

项目地址

注意：项目中用到 butterknife

单一样式

1. 实现 Adapter

    class SingleTypeAdapter extends EasyBaseAdapter {
        List list = new ArrayList<>();
   
        @Override
        protected List getList() {
            if (list.size() > 0) {
                return list;
            }
            // 构造数据
            for (int i = 0; i < 60; i++) {
                SingleTypeActivity.Result result = new SingleTypeActivity.Result();
                list.add(result);
            }
            return list;
        }
   
        // 构造 Item ViewHolder
        @Override
        protected EasyBaseAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int position) {
            // 创建 ItemView
            View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_1, null);
            return new SingleTypeViewHolder(view);
        }
    }
   

2. 实现ViewHolder
   class SingleTypeViewHolder extends EasyBaseAdapter.ViewHolder {

        @Bind(R.id.textView)
        TextView textView;
   
        public SingleTypeViewHolder(View view) {
            super(view);
        }
   
        @Override
        protected void updateView(View convertView, Result data, int position) {
            // 更新View 
            textView.setText(data.txt + position + "  " + (null == convertView));
        }
    }
   

3. 完成
   listView.setAdapter(new SingleTypeAdapter());

多样式

1. 实现Adapter
   class MutiTypeAdapter extends EasyBaseAdapter {

        // 一定要实现该方法
        @Override
        public int getViewTypeCount() {
            return 2;
        }
   
        // 一定要实现该方法
        @Override
        public int getItemViewType(int position) {
            if (0 == position % 2) {
                return 0;
            } else {
                return 1;
            }
        }
   
        List list = new ArrayList<>();
   
        @Override
        protected List getList() {
   
            if (list.size() > 0) {
                return list;
            }
            // 构造数据
            for (int i = 0; i < 60; i++) {
                MutiTypeActivity.Result result = new MutiTypeActivity.Result();
                list.add(result);
            }
            return list;
        }
   
        // 构造 Item ViewHolder
        @Override
        protected EasyBaseAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int position) {
            // 根据 ViewType 创建 ItemView
            if (0 == getItemViewType(position)) {
                View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_1, null);
                return new MutiTypeViewHolder1(view);
            } else {
                View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_2, null);
                return new MutiTypeViewHolder2(view);
            }
        }
    }
   

2. 实现ViewHolder
   class MutiTypeViewHolder1 extends EasyBaseAdapter.ViewHolder {

        @Bind(R.id.textView)
        TextView textView;
   
        public MutiTypeViewHolder1(View view) {
            super(view);
        }
   
        @Override
        protected void updateView(View convertView, Result data, int position) {
            // 更新View 
            textView.setText("刺激 + " + position + "   " + (null == convertView));
        }
    }
   
    class MutiTypeViewHolder2 extends EasyBaseAdapter.ViewHolder {
   
        @Bind(R.id.imageView)
        ImageView imageView;
   
        public MutiTypeViewHolder2(View view) {
            super(view);
        }
   
        @Override
        protected void updateView(View convertView, Result data, int position) {
            // 更新View 
            imageView.setImageResource(R.mipmap.rr);
          }
    }
   

3. 完成
   listView.setAdapter(new SingleTypeAdapter());

注意：多样式ListView 的 Adapter 中一定要实现 getViewTypeCount() 和 getItemViewType()这两个方法。其余照搬就好。