2.5 构建可复用的BaseAdapter
一、布局文件
1、MainActivity.xml 布局代码：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">
<ListView
android:id="@+id/list_book"
android:layout_width="wrap_content"
android:layout_weight="1"
android:layout_height="wrap_content"/>
<ListView
android:id="@+id/list_app"
android:layout_width="wrap_content"
android:layout_weight="1"
android:layout_height="wrap_content"/>
LinearLayout>
2、新建一个布局文件：item_one.xml，布局代码如下：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">
<ImageView
android:id="@+id/img_icon"
android:layout_width="64dp"
android:layout_height="64dp"
android:src="@mipmap/ic_launcher" />
<TextView
android:id="@+id/txt_aname"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginTop="20dp"
android:text="百度"
android:textSize="20sp" />
LinearLayout>
2、新建一个布局文件：item_two.xml，布局代码如下：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">
<TextView
android:id="@+id/txt_bname"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="《第一行代码Android》"
android:textColor="#F3684A"
android:textSize="18sp" />
<TextView
android:id="@+id/txt_bauthor"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:text="郭霖"
android:textColor="#44BDED"
android:textSize="18sp" />
LinearLayout>
Java代码
1、MyAdapter.java，可复用的BaseAdapter,代码如下：
package com.example.yuancan.test0926001;
import android.content.Context;
import android.util.SparseArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.ArrayList;
/**
* Created by yuancan on 16/9/26.
*/
public abstract class MyAdapter extends BaseAdapter {
private ArrayList mData;
private int mLayoutRes; //布局id
public MyAdapter() {
}
public MyAdapter(ArrayList mData, int mLayoutRes) {
this.mData = mData;
this.mLayoutRes = mLayoutRes;
}
@Override
public int getCount() {
return mData != null ? mData.size() : 0;
}
@Override
public T getItem(int position) {
return mData.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = ViewHolder.bind(parent.getContext(), convertView, parent, mLayoutRes
, position);
bindView(holder, getItem(position));
return holder.getItemView();
}
public abstract void bindView(ViewHolder holder, T obj);
public void add(T data) {
if (mData == null) {
mData = new ArrayList<>();
}
mData.add(data);
notifyDataSetChanged();
}
public void add(int position, T data) {
if (mData == null) {
mData = new ArrayList<>();
}
mData.add(position,data);
notifyDataSetChanged();
}
public void remove(T data) {
if (mData != null) {
mData.remove(data);
}
notifyDataSetChanged();
}
public void remove(int position) {
if (mData != null) {
mData.remove(position);
}
notifyDataSetChanged();
}
public static class ViewHolder {
private SparseArray mViews;
private View item;
private int position;
private Context context;
ImageView img_icon;
TextView txt_content;
private ViewHolder(Context context, ViewGroup parent, int layoutRes){
mViews = new SparseArray<>();
this.context = context;
View convertView = LayoutInflater.from(context).inflate(layoutRes,parent,false);
convertView.setTag(this);
item = convertView;
}
public static ViewHolder bind(Context context, View convertView, ViewGroup parent, int layoutRes, int position) {
ViewHolder holder;
if (convertView == null) {
holder = new ViewHolder(context,parent,layoutRes);
} else {
holder = (ViewHolder)convertView.getTag();
holder.item = convertView;
}
holder.position = position;
return holder;
}
public T getView(int id) {
T t = (T)mViews.get(id);
if(t == null) {
t = (T)item.findViewById(id);
mViews.put(id,t);
}
return t;
}
public View getItemView() {
return item;
}
public int getItemPosition() {
return position;
}
public ViewHolder setText(int id, CharSequence text) {
View view = getView(id);
if (view instanceof TextView) {
((TextView) view).setText(text);
}
return this;
}
public ViewHolder setImageResource(int id,int drawableRes) {
View view = getView(id);
if (view instanceof ImageView) {
((ImageView) view).setImageResource(drawableRes);
}else {
view.setBackgroundResource(drawableRes);
}
return this;
}
/**
* 设置点击监听
*/
public ViewHolder setOnClickListener(int id, View.OnClickListener listener) {
getView(id).setOnClickListener(listener);
return this;
}
/**
* 设置可见
*/
public ViewHolder setVisibility(int id, int visible) {
getView(id).setVisibility(visible);
return this;
}
/**
* 设置标签
*/
public ViewHolder setTag(int id, Object obj) {
getView(id).setTag(obj);
return this;
}
}
}
2、App.java ,数据类，代码如下：
package com.example.yuancan.test0926001;
/**
* Created by yuancan on 16/9/27.
*/
public class App {
private int aIcon;
private String aName;
public App() {
}
public App(int aIcon, String aName) {
this.aIcon = aIcon;
this.aName = aName;
}
public int getaIcon() {
return aIcon;
}
public String getaName() {
return aName;
}
public void setaIcon(int aIcon) {
this.aIcon = aIcon;
}
public void setaName(String aName) {
this.aName = aName;
}
}
3、Book.java，数据类，代码如下:
package com.example.yuancan.test0926001;
/**
* Created by yuancan on 16/9/27.
*/
public class Book {
private String bName;
private String bAuthor;
public Book() {
}
public Book(String bName, String bAuthor) {
this.bName = bName;
this.bAuthor = bAuthor;
}
public String getbName() {
return bName;
}
public String getbAuthor() {
return bAuthor;
}
public void setbName(String bName) {
this.bName = bName;
}
public void setbAuthor(String bAuthor) {
this.bAuthor = bAuthor;
}
}
4、MainActivity.java， 代码如下：
package com.example.yuancan.test0926001;
import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ListView;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.HashMap;
public class MainActivity extends AppCompatActivity {
private Context mContext;
private ListView list_book;
private ListView list_app;
private MyAdapter myAdapter1 = null;
private MyAdapter myAdapter2 = null;
private List mData1 = null;
private List mData2 = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mContext = MainActivity.this;
init();
}
private void init() {
list_book = (ListView) findViewById(R.id.list_book);
list_app = (ListView) findViewById(R.id.list_app);
//数据初始化
mData1 = new ArrayList();
mData1.add(new App(R.mipmap.ic_launcher,"百度"));
mData1.add(new App(R.mipmap.ic_launcher,"豆瓣"));
mData1.add(new App(R.mipmap.ic_launcher,"支付宝"));
mData2 = new ArrayList();
mData2.add(new Book("《第一行代码Android》", "郭霖"));
mData2.add(new Book("《Android群英传》","徐宜生"));
mData2.add(new Book("《Android开发艺术探索》","任玉刚"));
//Adapter初始化
myAdapter1 = new MyAdapter((ArrayList)mData1,R.layout.item_one) {
@Override
public void bindView(ViewHolder holder, App obj) {
holder.setImageResource(R.id.img_icon,obj.getaIcon());
holder.setText(R.id.txt_aname,obj.getaName());
}
};
myAdapter2 = new MyAdapter((ArrayList)mData2,R.layout.item_two) {
@Override
public void bindView(ViewHolder holder, Book obj) {
holder.setText(R.id.txt_bname,obj.getbName());
holder.setText(R.id.txt_bauthor,obj.getbAuthor());
}
};
//ListView设置下Adapter：
list_book.setAdapter(myAdapter2);
list_app.setAdapter(myAdapter1);
}
} 