打造一個萬能的適配器！！！

最近項目中 常常用listView和GridView ，能夠說是項目中Listview GridView幾乎是必用的組件，Android也提供一套機制，爲這些控件綁定數據，那就是Adapter 最近抽了時間，本身也打造了一個萬能的適配器

看咱們以前的一些寫法：

public class ImageViewAdapter2 extends RecyclerView.Adapter<ImageViewAdapter2.MyViewHolder> {
    private SweatQuestryModel deviceDataBean;
    private Context context;
    private ArrayList<String> urls = null;
    public ImageViewAdapter2(Context context, SweatQuestryModel deviceDataBean) {
        this.context = context;
        this.deviceDataBean = deviceDataBean;
        initImageUrl(deviceDataBean);
    }

    private void initImageUrl(SweatQuestryModel deviceDataBean) {
        urls = new ArrayList<>();
        if(urls != null){
            urls.addAll(deviceDataBean.getList());
        }
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.item_imageview, null);
        MyViewHolder holder = new MyViewHolder(view);
        return holder;
    }

    @Override
    public void onBindViewHolder(MyViewHolder holder, final int position) {
        GlideUtil.loadNetImg2(context, holder.image, urls.get(position) , R.drawable.default_square_image);
        holder.image.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Bundle bundle = new Bundle();
                bundle.putStringArrayList("imgUrls",urls);
                bundle.putInt("position", position);
                bundle.putInt("type", PictureActivity.TYPE_NET_IMG);
                ActivityUtils.showActivity(context, PictureActivity.class, bundle);
            }
        });

    }

    @Override
    public int getItemCount() {
        return deviceDataBean == null ? 0 : 9;
    }

    class MyViewHolder extends RecyclerView.ViewHolder {
        ImageView image;

        public MyViewHolder(View itemView) {
            super(itemView);
            image = (ImageView) itemView.findViewById(R.id.sweat_recycler_image);
        }
    }
}
複製代碼

這樣用起來雖然還不錯，但每次都須要去繼承一個BaseAdapter，而後實現裏面的一大堆方法，而咱們每次最關心的無非就是getView方法，其他的方法幾乎都是相同代碼。這裏是否是就能夠優化起來呢？在其次，咱們在使用Adapter的時候，爲了優化性能，經常會建立一個Holder。而Holder裏面每次存放的都是View，對Holer的操做無非也就是初始化，綁定數據，複用。這裏是否是也能夠抽取抽取？ 若是咱們封裝後：

/**
 * 類功能描述：</br>
 *v Viewholder
 * @author yuyahao
 * @version 1.0 </p> 修改時間：</br> 修改備註：</br>
 */
public class VolTeamAdapter extends CommonAdapter<Bean> {

    private Context context;
    public VolTeamAdapter(Context context, List<Bean> listDatas,   int layoutId) {
        super(context, listDatas, layoutId);
    }

    @Override
    protected void fillData(ViewHolder holder, int position) {
        TextView actNum = holder.getView(R.id.team_item_active_num);
        TextView time = holder.getView(R.id.team_item_time);
        TextView title = holder.getView(R.id.team_item_title);
        ImageView icon = holder.getView(R.id.team_item_icon);
        Bean item = listDatas.get(position);
        actNum.setText(String.valueOf(item.getActiveSum()) + "個");
        time.setText(String.valueOf(item.getTimeSun()) + "h");
        title.setText(item.getName());

        GlideUtil.loadNetImgC(context,icon, item.getPhoto(), R.drawable.bg_app_title);
    }
}
複製代碼

這樣是否是簡單多了。每次 寫adapter均可以這樣用。

第一步：構造 BaseAdapter

**
 * 類功能描述：</br>
 *v 使用
 * @author yuyahao
 * @version 1.0 </p> 修改時間：</br> 修改備註：</br>
 */
public class VolTeamAdapter extends CommonAdapter<Bean> {

    private Context context;
    public VolTeamAdapter(Context context, List<Bean> listDatas,   int layoutId) {
        super(context, listDatas, layoutId);
        this.context = context;
    }

    @Override
    protected void fillData(ViewHolder holder, int position) {
        TextView actNum = holder.getView(R.id.team_item_active_num);
        TextView time = holder.getView(R.id.team_item_time);
        TextView title = holder.getView(R.id.team_item_title);
        ImageView icon = holder.getView(R.id.team_item_icon);
        Bean item = listDatas.get(position);
        actNum.setText(String.valueOf(item.getActiveSum()) + "個");
        time.setText(String.valueOf(item.getTimeSun()) + "h");
        title.setText(item.getName());

        GlideUtil.loadNetImgC(context,icon, item.getPhoto(), R.drawable.bg_app_title);
    }
}
複製代碼

好了，別賣關子了，直接上所有代碼。

/**
 * 類功能描述：</br>
 *v Viewholder
 * @author yuyahao
 * @version 1.0 </p> 修改時間：</br> 修改備註：</br>
 */
public abstract class CommonAdapter<T> extends BaseAdapter {
    /*** 上下文的Context*/
    protected Context mContext;


    /*** list的數據*/
    protected List<T> listDatas;

    /** Item佈局ID*/
    protected int layoutId;


    public CommonAdapter(Context context, List<T> listDatas, int layoutId) {
        this.mContext = context;
        this.listDatas = listDatas;
        this.layoutId = layoutId;
    }

    @Override
    public int getCount() {
        return listDatas == null ? 0 : listDatas.size();
    }

/**
 * 獲取當前點擊的Item的數據時用
 * 在onItemClick中 parent.getAdapter().getItem(),獲取當前點擊的Item的數據
 */
    @Override
    public Object getItem(int position) {
        return listDatas.get(position);
    }

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

    /**
     *加載每個Item，該方法是最關鍵的
     */
@   Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = ViewHolder.getViewHolder(mContext, convertView,  parent, layoutId, position);
        fillData(holder, position);
        return holder.getMConvertView();
    }

    /**
     *
     * 抽象方法，用於子類實現，填充數據
     * @param holder
     * @param position
     */
    protected abstract void fillData(ViewHolder holder, int position);
}
複製代碼

第二步Holer的通用化

/**
 * 類功能描述：</br>
 *v Viewholder
 * @author yuyahao
 * @version 1.0 </p> 修改時間：</br> 修改備註：</br>
 */
public class ViewHolder {
    private  int mPosition;
    /**
     * View容器，用於存放Holer中的View
     * 據網上說是 SparseArray是這樣的
     * SparseArray 是Android推薦使用的一個優化容器，至關於一個Map<integer,View>
     */
    private SparseArray<View> mViews;

    /**
     * Item佈局View convertView
     */
    private View mConvertView;
    public ViewHolder(Context context, ViewGroup parent, int layoutId) {
        mViews = new SparseArray<View>();
        mConvertView = LayoutInflater.from(context).inflate(layoutId, null);
        mConvertView.setTag(this);
    }

    /**
     * 獲取ViewHolder
     * @param context
     *  上下文
     * @param convertView
     * @param parent
     * @param layoutId
     *            佈局layout Id
     * @param
     * @return
     */

    public static ViewHolder getViewHolder(Context context, View convertView,  ViewGroup parent, int layoutId) {
        if (convertView == null)
            return new ViewHolder(context, parent, layoutId);
        return (ViewHolder) convertView.getTag();
    }



    public ViewHolder(Context context, ViewGroup parent, int layoutId, int position) {
        this.mViews = new SparseArray<View>();
        this.mPosition = position;
        this.mConvertView = LayoutInflater.from(context).inflate(layoutId,
                parent, false);
        this.mConvertView.setTag(this);
    }
    /**
     * 拿到一個ViewHolder對象
     * @param context
     * @param convertView
     * @param parent
     * @param layoutId
     * @param position
     * @return
     */
    public static ViewHolder getViewHolder(Context context, View convertView, ViewGroup parent, int layoutId, int position) {
        if (null == convertView) {
            return new ViewHolder(context, parent, layoutId, position);
        } else {
            ViewHolder holder = (ViewHolder) convertView.getTag();
            holder.mPosition = position;
            return holder;
        }
    }
    /**
     * 獲取Holder中的ItemView
     * @param viewId
     * @return
     */
    @SuppressWarnings("unchecked")
    public <T extends View> T getView(int viewId) {
        View item = mViews.get(viewId);
        if (item == null) {
            item = mConvertView.findViewById(viewId);
            mViews.put(viewId, item);
        }
        return (T) item;
    }

    /** * 獲取convertView***/
    public View getMConvertView() {
        return mConvertView;
    }

}
複製代碼

這樣已經寫完。

第三步使用

/**
 * 類功能描述：</br>
 *v 使用
 * @author yuyahao
 * @version 1.0 </p> 修改時間：</br> 修改備註：</br>
 */
public class VolTeamAdapter extends CommonAdapter<Bean> {

    private Context context;
    public VolTeamAdapter(Context context, List<Bean> listDatas,   int layoutId) {
        super(context, listDatas, layoutId);
        this.context = context;
    }

    @Override
    protected void fillData(ViewHolder holder, int position) {
        TextView actNum = holder.getView(R.id.team_item_active_num);
        TextView time = holder.getView(R.id.team_item_time);
        TextView title = holder.getView(R.id.team_item_title);
        ImageView icon = holder.getView(R.id.team_item_icon);
        Bean item = listDatas.get(position);
        actNum.setText(String.valueOf(item.getActiveSum()) + "");
        time.setText(String.valueOf(item.getTimeSun()) + "");
        title.setText(item.getName());

        GlideUtil.loadNetImgC(context,icon, item.getPhoto(), R.drawable.bg_app_title);
    }
}
複製代碼

mainActivity：

public class MyTextActivity extends BaseActivity{
    private Context cnt;
    @Bind(R.id.lv_list)
    ListView  lv_list;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addViewFillInRoot(R.layout.ctivity_mytext);
        ButterKnife.bind(this);
        cnt = this;
        initView();
    }


    private void initView() {
        try {
            List<Bean>  list = DataTest.getMyTestList();
            VolTeamAdapter volTeamAdapter = new VolTeamAdapter(cnt,list,R.layout.my_listr);
            lv_list.setAdapter(volTeamAdapter);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
複製代碼

xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:gravity="center_vertical"
    android:layout_height="match_parent">
    <ImageView
        android:layout_width="@dimen/dp80"
        android:layout_height="@dimen/dp80"
        android:background="@drawable/default_head"
        android:scaleType="fitXY"
        android:id="@+id/team_item_icon"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_marginLeft="@dimen/dp10"
        android:orientation="vertical"
        android:layout_height="@dimen/dp80">
        <TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/team_item_title"
            android:gravity="center_vertical"
            android:layout_weight="1"
            android:text="卡卡羅特"/>
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_weight="1"
            android:layout_height="match_parent"
            android:gravity="center_vertical">
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="天不排名"
                android:id="@+id/team_item_time"/>
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="@dimen/dp20"
                android:text="戰鬥值： "

                android:id="@+id/team_item_active_num"/>

        </LinearLayout>
    </LinearLayout>
</LinearLayout>
複製代碼

效果圖：