Android万能适配器Adapter

万能适配器的代码的github地址是https://github.com/fengsehng/CommonAdapter

欢迎大家补充

我们经常要书写Adapter,但是Adapter里面的重复代码很多,所以我们可以复用一下 ,只要是ViewHolder的部分和Adapter的部分

常用的继承BaseAdapter的Adapter的代码如下

package com.example.euler_kalvinhe.myadapter.adapter;

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

import com.example.euler_kalvinhe.myadapter.R;
import com.example.euler_kalvinhe.myadapter.bean.Bean;

import java.util.List;

/**
* Created by Euler-KalvinHe on 2015/8/20.
*/
public class MyAdapter  extends BaseAdapter{
private LayoutInflater inflater;
private List<Bean> listData;
public MyAdapter(Context context,List<Bean> list) {
inflater = LayoutInflater.from(context);
this.listData = list;
}

@Override
public int getCount() {
return listData.size();
}

@Override
public Object getItem(int i) {
return listData.get(i);
}

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

@Override
public View getView(int i, View view, ViewGroup viewGroup) {
ViewHolder holder;
if (view == null){
view = inflater.inflate(R.layout.item,viewGroup,false);
holder = new ViewHolder();
holder.title = (TextView) view.findViewById(R.id.title);
holder.desc = (TextView) view.findViewById(R.id.desc);
holder.time = (TextView) view.findViewById(R.id.time);
holder.phone = (TextView) view.findViewById(R.id.phone);
view.setTag(holder);
}
else {
holder = (ViewHolder) view.getTag();
}
Bean bean = listData.get(i);
holder.title.setText(bean.getTitle());
holder.desc.setText(bean.getDesc());
holder.time.setText(bean.getTime());
holder.phone.setText(bean.getPhone());
return view;
}
private class ViewHolder{
TextView title;
TextView desc;
TextView time;
TextView phone;
}
}

对ViewHolder进行进行抽取,主要是初始化布局,判断ConvertView是否已经建立 ,注意重用Viewholder的时候position的设置,代码如下

package com.example.euler_kalvinhe.myadapter.utility;
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;

public class ViewHolder
{
private final SparseArray<View> mViews;
private int mPosition;
private View mConvertView;

private ViewHolder(Context context, ViewGroup parent, int layoutId,
int position)
{
this.mPosition = position;
this.mViews = new SparseArray<View>();
mConvertView = LayoutInflater.from(context).inflate(layoutId, parent,
false);
// setTag
mConvertView.setTag(this);
}

/**
* 拿到一个ViewHolder对象
*
* @param context
* @param convertView
* @param parent
* @param layoutId
* @param position
* @return
*/
public static ViewHolder get(Context context, View convertView,
ViewGroup parent, int layoutId, int position)
{
if (convertView == null)
{
return new ViewHolder(context, parent, layoutId, position);
}
return (ViewHolder) convertView.getTag();
}

public View getConvertView()
{
return mConvertView;
}

/**
* 通过控件的Id获取对于的控件，如果没有则加入views
*
* @param viewId
* @return
*/
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;
}

/**
* 为TextView设置字符串
*
* @param viewId
* @param text
* @return
*/
public ViewHolder setText(int viewId, String text)
{
TextView view = getView(viewId);
view.setText(text);
return this;
}

/**
* 为ImageView设置图片
*
* @param viewId
* @param drawableId
* @return
*/
public ViewHolder setImageResource(int viewId, int drawableId)
{
ImageView view = getView(viewId);
view.setImageResource(drawableId);

return this;
}

/**
* 为ImageView设置图片
*
* @param viewId
* @param drawableId
* @return
*/
public ViewHolder setImageBitmap(int viewId, Bitmap bm)
{
ImageView view = getView(viewId);
view.setImageBitmap(bm);
return this;
}

public int getPosition()
{
return mPosition;
}

}

Adapter类的抽取,主要是利用泛型实现了BaseAdapter的抽象方法

package  com.example.euler_kalvinhe.myadapter.utility;

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

import java.util.List;

public abstract class CommenAdapter<T> extends BaseAdapter
{
protected LayoutInflater mInflater;
protected Context mContext;
protected List<T> mDatas;
protected final int mItemLayoutId;

public CommenAdapter(Context context, List<T> mDatas, int itemLayoutId)
{
this.mContext = context;
this.mInflater = LayoutInflater.from(mContext);
this.mDatas = mDatas;
this.mItemLayoutId = itemLayoutId;
}

@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)
{
final ViewHolder viewHolder = getViewHolder(position, convertView,
parent);
convert(viewHolder, getItem(position));
return viewHolder.getConvertView();

}

public abstract void convert(ViewHolder helper, T item);

private ViewHolder getViewHolder(int position, View convertView,
ViewGroup parent)
{
return ViewHolder.get(mContext, convertView, parent, mItemLayoutId,
position);
}

}

activity的代码.匿名实现了Adapter

package com.example.euler_kalvinhe.myadapter;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.CheckBox;
import android.widget.ListView;
import android.widget.TextView;

import com.example.euler_kalvinhe.myadapter.bean.Bean;
import com.example.euler_kalvinhe.myadapter.utility.CommenAdapter;
import com.example.euler_kalvinhe.myadapter.utility.ViewHolder;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends Activity {
private ListView listView;
private List<Bean> listData = new ArrayList<Bean>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initViews();
initData();
listView.setAdapter(new CommenAdapter<Bean>(MainActivity.this,listData,R.layout.item) {
@Override
public void convert(ViewHolder holder, final Bean bean) {
((TextView)holder.getView(R.id.title)).setText(bean.getTitle());
((TextView)holder.getView(R.id.desc)).setText(bean.getDesc());
((TextView)holder.getView(R.id.time)).setText(bean.getTime());
((TextView)holder.getView(R.id.phone)).setText(bean.getPhone());
final CheckBox checkBox = holder.getView(R.id.checkbox);
checkBox.setChecked(bean.isChecked());
checkBox.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
bean.setChecked(checkBox.isChecked());
}
});
}
});
}

private void initData() {
Bean bean = new Bean("android新技能","打造万能的adapter和Viewholder","201304","10086");
listData.add(bean);
Bean bean1 = new Bean("android新技能1","打造万能的adapter和Viewholder","201304","10086");
listData.add(bean1);
Bean bean2 = new Bean("android新技能2","打造万能的adapter和Viewholder","201304","10086");
listData.add(bean2);
Bean bean3 = new Bean("android新技能3","打造万能的adapter和Viewholder","201304","10086");
listData.add(bean3);
Bean bean4 = new Bean("android新技能4","打造万能的adapter和Viewholder","201304","10086");
listData.add(bean4);
Bean bean5 = new Bean("android新技能5","打造万能的adapter和Viewholder","201304","10086");
listData.add(bean5);
Bean bean6 = new Bean("android新技能6","打造万能的adapter和Viewholder","201304","10086");
listData.add(bean6);
Bean bean7 = new Bean("android新技能7","打造万能的adapter和Viewholder","201304","10086");
listData.add(bean7);
Bean bean8 = new Bean("android新技能8","打造万能的adapter和Viewholder","201304","10086");
listData.add(bean8);
Bean bean9 = new Bean("android新技能9","打造万能的adapter和Viewholder","201304","10086");
listData.add(bean9);
Bean bean10 = new Bean("android新技能10","打造万能的adapter和Viewholder","201304","10086");
listData.add(bean10);
Bean bean11= new Bean("android新技能11","打造万能的adapter和Viewholder","201304","10086");
listData.add(bean11);

}

private void initViews() {

listView = (ListView) findViewById(R.id.listView);
}
}

Bean是数据类,初始化了变量

package com.example.euler_kalvinhe.myadapter.bean;

/**
* Created by Euler-KalvinHe on 2015/8/20.
*/
public class Bean {
private String title;
private String desc;
private String phone;
private String time;
private boolean isChecked;

public Bean(String title, String desc, String time, String phone) {
this.desc = desc;
this.phone = phone;
this.time = time;
this.title = title;
}

public boolean isChecked() {
return isChecked;
}

public void setChecked(boolean isChecked) {
this.isChecked = isChecked;
}

public String getTitle() {
return title;
}

public void setTitle(String title) {
this.title = title;
}

public String getDesc() {
return desc;
}

public void setDesc(String desc) {
this.desc = desc;
}

public String getPhone() {
return phone;
}

public void setPhone(String phone) {
this.phone = phone;
}

public String getTime() {
return time;
}

public void setTime(String time) {
this.time = time;
}
}

布局类主要是主布局.包含ListView和item的布局

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

<ListView
android:id="@+id/listView"
android:layout_width="match_parent"
android:layout_height="match_parent"></ListView>

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="wrap_content"
android:descendantFocusability="blocksDescendants">
<!--android:focusable="false"-->
<CheckBox
android:id="@+id/checkbox"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
/>
<TextView
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#888"
android:text="android新技能"
android:textSize="16sp"
/>
<TextView
android:id="@+id/desc"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="打造万能的adapter和Viewholder"
android:minLines="1"
android:maxLines="2"
android:layout_toLeftOf="@id/checkbox"
android:layout_below="@id/title"
android:layout_marginTop="10dp"
android:textColor="#444"
android:textSize="16sp"/>
<TextView
android:id="@+id/time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="201304"
android:layout_below="@id/desc"
android:layout_marginTop="10dp"
android:textColor="#444"
android:textSize="12sp"/>
<TextView
android:id="@+id/phone"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="10086"
android:layout_below="@id/time"
android:layout_marginTop="10dp"
android:drawableLeft="@drawable/ic_action_phone_start"
android:drawablePadding="5dp"
android:padding="3dp"
android:textColor="#fff"
android:textSize="12sp"
android:layout_alignParentRight="true"
android:background="#ff2447ff"/>

</RelativeLayout>

效果图

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!要注意的两个问题

1.第一个item中加入了CheckBox,CheckBox会抢焦点,使得勾选自己有效,然而点击整个item无效,这个问题,可以通过在item的根布局RelativeLayout里面加一句 android:descendantFocusability=”blocksDescendants”

2.第二个问题就是由于ViewHolder的复用导致,勾选前面的CheckBox,后面的自动勾选,解决办法是在Bean加入一个表示CheckBox是否勾选的布尔变量isChecked,具体如下

Bean里面

private boolean isChecked;
ublic boolean isChecked() {
return isChecked;
}

public void setChecked(boolean isChecked) {
this.isChecked = isChecked;
}

activity里面

final CheckBox checkBox = holder.getView(R.id.checkbox);
checkBox.setChecked(bean.isChecked());
checkBox.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
bean.setChecked(checkBox.isChecked());
}
});

万能适配器的代码的github地址是https://github.com/fengsehng/CommonAdapter

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