vmei_day05

今天周五

学习安卓万能适配器

简化的adapter如下

package common;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;

import com.example.maguitao.demo.R;

import java.util.List;

/**
 * 万能的Adapter
 * Created by maguitao on 2016/12/15.
 */

public abstract class CommonAdapter<T> extends BaseAdapter {
    protected Context mContext;
    protected List<T> mDatas;
    protected LayoutInflater mlayoutInflater;

    public CommonAdapter(Context mContext ,List<T> mDatas) {
        this.mDatas = mDatas;
        this.mContext = mContext;
    }

    @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){
        ViewHolder holder=   ViewHolder.get(mContext,convertView,parent, R.layout.item,position);
        convert(holder,mDatas.get(position), position);
        return holder.getmConvetView();
    }
    public abstract void convert(ViewHolder holder, T bean, int position);
}

抽取的万能Viewholder如下

package common;

import android.content.Context;
import android.util.SparseArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

/**
 * 万能Viewholder
 * Created by maguitao on 2016/12/15.
 */

public class ViewHolder {
    private SparseArray<View> mViews;
    private int mPosition;
    private View mConvetView;
    public ViewHolder(Context context,ViewGroup parent,int layoutId,int position) {
        this.mPosition=position;
        this.mViews=new SparseArray<View>();
        mConvetView= LayoutInflater.from(context).inflate(layoutId,parent,false);
        mConvetView.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();
               return holder;
           }
    }
    /**
     * 获取每个view
     * @param viewId
     * @param <T>
     * @return
     */
    public  <T extends View> T getView(int viewId){
        View view=mViews.get(viewId);
        if (view==null){
            view=mConvetView.findViewById(viewId);
            mViews.put(viewId,view);
        }
        return (T) view;
    }

    /**
     * 返回convertview
     * @return
     */
    public View getmConvetView(){
        return mConvetView;
    }
}

package com.example.maguitao.demo.adapter;

import android.content.Context;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;

import com.example.maguitao.demo.R;

import java.util.List;

import common.CommonAdapter;
import common.ViewHolder;

/**
 * Created by maguitao on 2016/12/15.
 */

public class MyAdapter extends CommonAdapter<String> {
    public MyAdapter(Context mContext, List mDatas) {
        super(mContext, mDatas);
    }



    @Override
    public void convert(ViewHolder holder, String bean, final int position) {
        TextView tv_title=holder.getView(R.id.tv_title);
        tv_title.setText(bean);
        tv_title.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(mContext,"点击的位置是"+position+"",Toast.LENGTH_SHORT).show();
            }
        });
    }


}