android adapter公共写法

在开发过程中,会写很多的adapter类,其中很多公共的部分,不需要每次都去书写,可以为开发者省下很多时间

提取一个ListViewAdapter

public abstract class ListViewAdapter<T> extends BaseAdapter {

    //为了让子类访问,于是将属性设置为protected
    protected Context mContext;
    protected List<T> mDatas;
    protected LayoutInflater mInflater;
    private int layoutId; //不同的ListView的item布局肯能不同,所以要把布局单独提取出来

    public ListViewAdapter(Context context, List<T> datas, int layoutId) {
        this.mContext = context;
        mInflater = LayoutInflater.from(context);
        this.mDatas = datas;
        this.layoutId = layoutId;
    }

    @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;
    }

    /**
     * 添加数据,
     *
     * @param aList
     */
    public void addData(List<T> aList) {
        if (aList != null && aList.size() > 0) {
            mDatas.addAll(aList);
        }
        notifyDataSetChanged();
    }

    /**
     * 获取数据
     *
     * @return
     */
    public List<T> getData() {
        return mDatas;
    }

    /**
     * 设置数据,
     *
     * @param sList
     */
    public void setData(List<T> sList) {
        mDatas.clear();
        addData(sList);
    }

    /**
     * 清空数据
     */
    public void clear() {
        mDatas.clear();
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        //初始化ViewHolder,使用通用的ViewHolder,一样代码就搞定ViewHolder的初始化咯
        ViewHolder holder = ViewHolder.get(mContext, convertView, parent, layoutId, position);//layoutId就是单个item的布局

        convert(holder, getItem(position));
        return holder.getConvertView(); //这一行的代码要注意了
    }

    //将convert方法公布出去
    public abstract void convert(ViewHolder holder, T t);

}
View Code

可复用ViewHolder代码

public class ViewHolder {
    private SparseArray<View> mViews;
    private int mPosition;
    private View mConvertView;

    public ViewHolder(Context context, ViewGroup parent, int layoutId, int position) {
        this.mPosition = position;
        this.mViews = new SparseArray<View>();

        mConvertView = LayoutInflater.from(context).inflate(layoutId, parent, false);
        mConvertView.setTag(this);
    }

    public static ViewHolder get(Context context, View convertView, ViewGroup parent, int layoutId, int position) {
        if (convertView == null) {
            return new ViewHolder(context, parent, layoutId, position);
        } else {
            ViewHolder holder = (ViewHolder) convertView.getTag();
            holder.mPosition = position; //即时ViewHolder是复用的,但是position记得更新一下
            return holder;
        }
    }

    /*
    通过viewId获取控件
     */
    //使用的是泛型T,返回的是View的子类
    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;
    }

    public View getConvertView() {
        return mConvertView;
    }
}
View Code

再看看现在的adapter类

public class ExampleAdapter extends ListViewAdapter<String> {
    public MsgTemplateAdapter(Context context, List<String> datas) {
        super(context, datas, R.layout.template_list_item);
    }

    @Override
    public void convert(ViewHolder holder, String s) {
        ((TextView) holder.getView(R.id.name)).setText(s);
    }
}
View Code

看到这么简洁的代码,是不是感觉整个人都精神了

1.android studio使用maven

repositories {
    maven {
        url 'https://dl.bintray.com/ping/maven/'
    }
}

dependencies {
    ...
    compile 'com.github.liuping123.commadapter:commadapter:0.0.3@aar'
}

2.android studio使用jcenter

compile 'com.github.liuping123.commadapter:commadapter:0.0.3'

 

Github地址:https://github.com/liuping123/CommAdapter

 

参考:http://www.cnblogs.com/smyhvae/p/4477079.html

 

 

 

【声明】 

欢迎转载,但请保留文章原始出处

博客地址:http://www.cnblogs.com/lping/

文章来源:http://www.cnblogs.com/lping/p/5470781.html

 

posted on 2016-05-08 15:48  木头平  阅读(1395)  评论(0编辑  收藏  举报

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