Android中ListView结合CheckBox判断选中项

时间:2021-11-13 19:45:29

             本文主要实现在自定义的ListView布局中加入CheckBox控件,通过判断用户是否选中CheckBox来对ListView的选中项进行相应的操作。通过一个Demo来展示该功能,选中ListView中的某一项,然后点击Button按钮来显示选中了哪些项。

[1] 程序结构图如下:

Android中ListView结合CheckBox判断选中项

其中Person.java是实体类,MainActivity.java是Activity组件类。listitem.xml是自定义的列表每项布局文件。

[2] listitem.xml布局文件源码如下:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:descendantFocusability="blocksDescendants">
<CheckBox
android:id="@+id/list.select"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<TextView
android:id="@+id/list.name"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Name"
android:layout_gravity="center"
android:textSize="20dp"
android:layout_marginLeft="10dp"/>
<TextView
android:id="@+id/list.address"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Address"
android:layout_gravity="center"
android:textSize="20dp"/>
</LinearLayout>
</LinearLayout>

[3] main.xml布局文件源码如下:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Button
android:id="@+id/show"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Show"/>
<ListView
android:id="@+id/lvperson"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
</LinearLayout>

[4] Person.java实体类源码如下:

package com.andyidea.bean;

public class Person {

private String name;
private String address;

public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}

}

[5] MainActivity.java类源码如下:

package com.andyidea.listview;

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

import com.andyidea.bean.Person;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends Activity {

Button show;
ListView lv;
List<Person> persons = new ArrayList<Person>();
Context mContext;
MyListAdapter adapter;
List<Integer> listItemID = new ArrayList<Integer>();

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mContext = getApplicationContext();
show = (Button)findViewById(R.id.show);
lv = (ListView)findViewById(R.id.lvperson);

initPersonData();
adapter = new MyListAdapter(persons);
lv.setAdapter(adapter);

show.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {

listItemID.clear();
for(int i=0;i<adapter.mChecked.size();i++){
if(adapter.mChecked.get(i)){
listItemID.add(i);
}
}

if(listItemID.size()==0){
AlertDialog.Builder builder1 = new AlertDialog.Builder(MainActivity.this);
builder1.setMessage("没有选中任何记录");
builder1.show();
}else{
StringBuilder sb = new StringBuilder();

for(int i=0;i<listItemID.size();i++){
sb.append("ItemID="+listItemID.get(i)+" . ");
}
AlertDialog.Builder builder2 = new AlertDialog.Builder(MainActivity.this);
builder2.setMessage(sb.toString());
builder2.show();
}
}
});
}

/**
* 模拟数据
*/
private void initPersonData(){
Person mPerson;
for(int i=1;i<=12;i++){
mPerson = new Person();
mPerson.setName("Andy"+i);
mPerson.setAddress("GuangZhou"+i);
persons.add(mPerson);
}
}

//自定义ListView适配器
class MyListAdapter extends BaseAdapter{
List<Boolean> mChecked;
List<Person> listPerson;
HashMap<Integer,View> map = new HashMap<Integer,View>();

public MyListAdapter(List<Person> list){
listPerson = new ArrayList<Person>();
listPerson = list;

mChecked = new ArrayList<Boolean>();
for(int i=0;i<list.size();i++){
mChecked.add(false);
}
}

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

@Override
public Object getItem(int position) {
return listPerson.get(position);
}

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

@Override
public View getView(int position, View convertView, ViewGroup parent) {
View view;
ViewHolder holder = null;

if (map.get(position) == null) {
Log.e("MainActivity","position1 = "+position);

LayoutInflater mInflater = (LayoutInflater) mContext
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = mInflater.inflate(R.layout.listitem, null);
holder = new ViewHolder();
holder.selected = (CheckBox)view.findViewById(R.id.list_select);
holder.name = (TextView)view.findViewById(R.id.list_name);
holder.address = (TextView)view.findViewById(R.id.list_address);
final int p = position;
map.put(position, view);
holder.selected.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
CheckBox cb = (CheckBox)v;
mChecked.set(p, cb.isChecked());
}
});
view.setTag(holder);
}else{
Log.e("MainActivity","position2 = "+position);
view = map.get(position);
holder = (ViewHolder)view.getTag();
}

holder.selected.setChecked(mChecked.get(position));
holder.name.setText(listPerson.get(position).getName());
holder.address.setText(listPerson.get(position).getAddress());

return view;
}

}

static class ViewHolder{
CheckBox selected;
TextView name;
TextView address;
}
}

[6] 程序运行后的结果如下:

Android中ListView结合CheckBox判断选中项