adapter万能适配器

adapter万能适配器

看了慕课网adapter万能适配器的视频，记录一下。

首先定义一个ViewHolder，item复用和避免重复findViewById：

package com.hou;import android.content.Context;import android.graphics.Bitmap;import android.util.SparseArray;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import android.widget.TextView;/** * Created by hp on 2016/3/11. */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<>();        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();            return holder;        }    }    /**     * 通过viewId获取控件     */    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;    }    /**     * 给TextView设值     */    public ViewHolder setText(int viewId, String text) {        TextView tv = getView(viewId);        tv.setText(text);        return this;    }    /**     * 给ImageView设值resource     */    public ViewHolder setImageResource(int viewId, int resId) {        ImageView iv = getView(viewId);        iv.setImageResource(resId);        return this;    }    /**     * 给ImageView设Bitmap     */    public ViewHolder setImageBitmap(int viewId, Bitmap bitmap) {        ImageView iv = getView(viewId);        iv.setImageBitmap(bitmap);        return this;    }}

重写BaseAdapter，CommonAdapter.java:

package com.hou;import android.content.Context;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import java.util.List;/** * 万能适配器 */public abstract class CommonAdapter<T> extends BaseAdapter {    protected Context mContext;    protected List<T> mDatas;    private LayoutInflater mInflater;    private int mLayoutId;    public CommonAdapter(Context context, int layoutId, List<T> datas) {        this.mContext = context;        mInflater = LayoutInflater.from(context);        this.mLayoutId = layoutId;        this.mDatas = datas;    }    @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, mLayoutId, position);        convert(holder, getItem(position));        return holder.getConvertView();    }    public abstract void convert(ViewHolder holder, T t);}

这样只需要把这两个文件复制到项目中就可以开始使用了。

定义一个adapter，MyAdapter.java，继承CommonAdapter:

package com.hou.aidlclient;import android.content.Context;import com.hou.CommonAdapter;import com.hou.ViewHolder;import com.hou.aidl.Person;import java.util.List;public class MyAdapter extends CommonAdapter<Person> {    public MyAdapter(Context context, List<Person> datas) {        //这里需要传递给CommonAdapter三个参数：Context ，布局文件，数据集合        super(context, R.layout.item, datas);    }//现在不需要重写BaseAdapter中的其他方法，只需要重写父类的convert方法即可，//而代码也只有简单的一句。    @Override    public void convert(ViewHolder holder, Person person) {        holder.setImageResource(R.id.icon, R.mipmap.ic_launcher).setText(R.id.name, "\t姓名：" + person.name).setText(R.id.age, "\t年龄：" + person.age + "");    }}

运行效果如图；