Android项目实践——自定义RecyclerViewAdapter模板代码

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前言：项目开发中难免会敲很多重复的代码，尤其是像 Adapter（适配器）这种使用频率高且格式基本一致的类，这篇博客将以 RecyclerViewAdapter为例教大家如何自定义自己的模板代码实现一键生成

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一般RecyclerViewAdapter中会包含初始化方法，ViewHolder，设置列表项点击或长按的接口等等，下面是RecyclerViewAdapter的一个例子

package com.test.bauztest.BaseRecyclerViewAdapter;//你的包名//各种类的导入import android.content.Context;import android.support.v7.widget.RecyclerView;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import java.util.List;import java.util.Map;//类的File Header/** * Created by anlia on 2017/10/30. */public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewAdapter.ViewHolder> {    private Context context;    private List<Map<String,String>> list;//声明一个传参类型为Map<String,String>的list    private OnItemClickListener mOnItemClickListener;    class ViewHolder extends RecyclerView.ViewHolder{        // TODO: 声明组件        public ViewHolder(View view) {            super(view);            // TODO: 注册组件,view.findViewById(R.id.xxx)        }    }    public MyRecyclerViewAdapter(Context context,List<Map<String,String>> list) {        this.context = context;        this.list = list;    }    public interface OnItemClickListener {        void onItemClick(View view, int position);        void onItemLongClick(View view , int position);    }    public void setOnItemClickListener(OnItemClickListener mOnItemClickListener){        this.mOnItemClickListener = mOnItemClickListener;    }    @Override    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        // TODO: 为对应itemViewId赋值,例：R.layout.xxx        int itemViewId = 0;        ViewHolder holder = new ViewHolder(LayoutInflater.from(context).inflate(itemViewId, parent, false));        return holder;    }    @Override    public void onBindViewHolder(final ViewHolder holder, int position) {        // TODO: 绑定组件的事件        // 如果设置了回调，则设置点击事件        if (mOnItemClickListener != null)        {            holder.itemView.setOnClickListener(new View.OnClickListener()            {                @Override                public void onClick(View v)                {                    int pos = holder.getLayoutPosition();                    mOnItemClickListener.onItemClick(holder.itemView, pos);                }            });            holder.itemView.setOnLongClickListener(new View.OnLongClickListener()            {                @Override                public boolean onLongClick(View v)                {                    int pos = holder.getLayoutPosition();                    mOnItemClickListener.onItemLongClick(holder.itemView, pos);                    return false;                }            });        }    }    @Override    public int getItemCount() {        return list.size();    }}

基本每个Adapter都包含上面这些内容，经常复制粘贴然后再去改类名是非常影响开发效率的一件事，我们可以利用Android Studio中设置模板代码的功能来减轻我们的负担，进入模板代码设置有两种方法
* 点击File → Settings → Editor → File and Code Templates，然后点击新增，编写我们的模板代码即可，如图

• 还有另外一种方法更加快捷，点击File → New → Edit File Templates

因为模板代码要有通用性，所以包名、类名以及List的传参我们都不能写死，上面的Adapter例子需要略微修改，注意模板代码中修改的地方

//自动生成包名#if (${PACKAGE_NAME} && ${PACKAGE_NAME} != "")package ${PACKAGE_NAME};#endimport android.content.Context;import android.support.v7.widget.RecyclerView;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import java.util.List;//用默认的File Header即可#parse("File Header.java")public class ${NAME}<E> extends RecyclerView.Adapter<${NAME}.ViewHolder> {//包名也需要自动生成，同时注意List传参为泛型    private Context context;    private List<E> list;//数据集合    private OnItemClickListener mOnItemClickListener;    class ViewHolder extends RecyclerView.ViewHolder{        // TODO: 声明组件        public ViewHolder(View view) {            super(view);            // TODO: 注册组件,view.findViewById(R.id.xxx)        }    }    public ${NAME}(Context context,List<E> list) {        this.context = context;        this.list = list;    }    public interface OnItemClickListener {        void onItemClick(View view, int position);        void onItemLongClick(View view , int position);    }    public void setOnItemClickListener(OnItemClickListener mOnItemClickListener){        this.mOnItemClickListener = mOnItemClickListener;    }    @Override    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        // TODO: 为对应itemViewId赋值,例：R.layout.xxx        int itemViewId = 0;        ViewHolder holder = new ViewHolder(LayoutInflater.from(context).inflate(itemViewId, parent, false));        return holder;    }    @Override    public void onBindViewHolder(final ViewHolder holder, int position) {        // TODO: 绑定组件的事件        // 如果设置了回调，则设置点击事件        if (mOnItemClickListener != null)        {            holder.itemView.setOnClickListener(new View.OnClickListener()            {                @Override                public void onClick(View v)                {                    int pos = holder.getLayoutPosition();                    mOnItemClickListener.onItemClick(holder.itemView, pos);                }            });            holder.itemView.setOnLongClickListener(new View.OnLongClickListener()            {                @Override                public boolean onLongClick(View v)                {                    int pos = holder.getLayoutPosition();                    mOnItemClickListener.onItemLongClick(holder.itemView, pos);                    return false;                }            });        }    }    @Override    public int getItemCount() {        return list.size();    }}

模板代码设置好后，我们只需要简单几步即可自动生成RecyclerViewAdapter代码

至此本篇教程到此结束，如果大家看了感觉还不错麻烦点个赞，你们的支持是我最大的动力~

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