ListView是开发中最常用的控件了,但是总是会写重复的代码,浪费时间又没有意义。
最近参考一些资料,发现一个万能ListView适配器,代码量少,节省时间,总结一下分享给大家。
首先有一个自定义的Adapter继承于baseAdapter,下面是自定义的Adapter,精华在getView()方法中
package com.example.mylistview.util; import java.util.List; import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.baseAdapter; public abstract class CommonAdapterextends baseAdapter { private Context mContext; private List mDatas; private LayoutInflater mInflater; private int mlayoutId; public CommonAdapter(Context context, List datas, int layoutId) { this.mContext = context; this.mDatas = datas; this.mlayoutId = layoutId; mInflater = LayoutInflater.from(context); } @Override public int getCount() { // TODO Auto-generated method stub return mDatas.size(); } @Override public T getItem(int arg0) { // TODO Auto-generated method stub return mDatas.get(arg0); } @Override public long getItemId(int arg0) { // TODO Auto-generated method stub return arg0; } @Override public View getView(int arg0, View arg1, ViewGroup arg2) { // TODO Auto-generated method stub ViewHolder holder = ViewHolder.get(mContext, arg1, arg2, mlayoutId, arg0); convert(holder, getItem(arg0)); return holder.getConvertView(); } public abstract void convert(ViewHolder holder, T t); }
以上的抽象方法convert(ViewHolder holder, T t);就相当于以前通用代码中的
viewHolder.mTextView = (TextView) convertView .findViewById(R.id.id_tv_title);
viewHolder.mTextView.setText(Bean.getName());
找到控件的id再去设施setText等重复的代码方法中的参数ViewHolder holder, T t holder就相当于以前通用代码中的viewHolder,t就相当于一个自己定义的实体类Bean。
以上代码中getView()方法中有一个ViewHolder是需要自己声明的,以下是代码以及详细注释:
package com.example.mylistview.util;
import android.content.Context;
import android.graphics.Bitmap;
import android.renderscript.Type;
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 SparseArray mViews;
private int mPosition;
private View mConvertView;
public View getConvertView() {
return mConvertView;
}
public ViewHolder(Context context, ViewGroup parent, int layoutId,
int position) {
this.mViews = new SparseArray();
this.mPosition = position;
this.mConvertView = LayoutInflater.from(context).inflate(layoutId,
parent, false);
this.mConvertView.setTag(this);
}
public static ViewHolder get(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;
}
}
public T getView(int viewId) {
View view = mViews.get(viewId);
if (null == view) {
view = mConvertView.findViewById(viewId);
mViews.put(viewId, view);
}
return (T) view;
}
public ViewHolder setText(int viewId, String text) {
TextView tv = getView(viewId);
tv.setText(text);
return this;
}
public ViewHolder setImageResource(int viewId, int drawableId)
{
ImageView view = getView(viewId);
view.setImageResource(drawableId);
return this;
}
public int getPosition()
{
return mPosition;
}
}
再写一个Adapter继承于万能适配器CommonAdapter,还是要写一个自己的Adapter,因为一个项目可能会有多个ListView,但是每个的item元素,布局都会有所不同的,这个泪用来区分不同的ListView与自己所对应的item.这个代码量较少完全可以写成内部类在Activity.java中.
package com.example.mylistview.adapter; import java.util.List; import android.content.Context; import android.view.View; import android.view.View.OnClickListener; import android.widget.CheckBox; import com.example.mylistview.R; import com.example.mylistview.domain.Bean; import com.example.mylistview.util.CommonAdapter; import com.example.mylistview.util.ViewHolder; public class MyAdapter extends CommonAdapter{ public MyAdapter(Context context, List datas, int layoutId) { super(context, datas, layoutId); // TODO Auto-generated constructor stub } @Override public void convert(ViewHolder holder, final Bean bean) { // TODO Auto-generated method stub holder.setText(R.id.tv_title, bean.getTitle()) .setText(R.id.tv_desc, bean.getDesc()) .setText(R.id.tv_time, bean.getTime()) .setText(R.id.tv_phone, bean.getPhone()); final CheckBox cBox = (CheckBox)(holder.getView(R.id.cb)); if (cBox != null) { cBox.setChecked(bean.isChecked()); cBox.setonClickListener(new onClickListener() { @Override public void onClick(View v) { bean.setChecked(cBox.isChecked()); } }); } } }
优化之后用适配器的时候就简单多了下面是实体类,item和MainActivity.java中的代码:
实体类:
package com.example.mylistview.domain;
public class Bean {
private String title;
private String desc;
private String time;
private String phone;
private boolean isChecked;
public boolean isChecked() {
return isChecked;
}
public void setChecked(boolean isChecked) {
this.isChecked = isChecked;
}
public Bean(String title, String desc, String time, String phone) {
this.title = title;
this.desc = desc;
this.time = time;
this.phone = phone;
}
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 getTime() {
return time;
}
public void setTime(String time) {
this.time = time;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
}
MainActivity.java:
重点代码:
参数有上下文,集合,和自己对应的item就可以了
adapter = new MyAdapter(this, mDatas, R.layout.item);
package com.example.mylistview.ui;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
import com.example.mylistview.R;
import com.example.mylistview.adapter.MyAdapter;
import com.example.mylistview.domain.Bean;
public class MainActivity extends Activity {
private ListView listView;
private List mDatas;
private MyAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
initData();
listener();
}
private void listener() {
// TODO Auto-generated method stub
listView.setonItemClickListener(new onItemClickListener() {
@Override
public void onItemClick(AdapterView> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
startActivity(new Intent(MainActivity.this, SecondActivity.class));
}
});
}
private void initData() {
// TODO Auto-generated method stub
mDatas = new ArrayList();
Bean bean = new Bean("Android新技能 Get",
"Android-打造万能的ListView和GridView适配器", "2015-08-05", "10086");
mDatas.add(bean);
bean = new Bean("捡到权志龙一个",
"在星巴克捡到权志龙一个", "2015-08-06", "10086");
mDatas.add(bean);
bean = new Bean("GetTOP一个",
"在韩国首尔捡到TOP一个", "2015-08-07", "10086");
mDatas.add(bean);
adapter = new MyAdapter(this, mDatas, R.layout.item);
listView.setAdapter(adapter);
}
private void initView() {
// TODO Auto-generated method stub
listView = (ListView) findViewById(R.id.listView);
}
}
item布局:
效果图:
用这个去适配另一个不同的布局:
新布局的Adapter一样继承自己的万能adapter:CommonAdapter
package com.example.mylistview.adapter; import java.util.List; import java.util.Map; import android.content.Context; import com.example.mylistview.R; import com.example.mylistview.util.CommonAdapter; import com.example.mylistview.util.ViewHolder; public class SecondAdapter extends CommonAdapter
Activity.java代码:
package com.example.mylistview.ui;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;
import com.example.mylistview.R;
import com.example.mylistview.adapter.MyAdapter;
import com.example.mylistview.adapter.SecondAdapter;
public class SecondActivity extends Activity {
private ListView listView_second;
private SecondAdapter secondAdapter;
private List> lists = new ArrayList>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
initView();
initData();
}
private void initData() {
// TODO Auto-generated method stub
for (int i = 0; i < 4; i++) {
Map map = new HashMap();
map.put("values", "条目" + i);
lists.add(map);
}
secondAdapter = new SecondAdapter(this, lists, R.layout.item2);
listView_second.setAdapter(secondAdapter);
}
private void initView() {
// TODO Auto-generated method stub
listView_second = (ListView) findViewById(R.id.listView_second);
}
}
item:
效果图:
以上就是对Android ListView 的资料整理,希望能给大家带来帮助!



