Android listview + checkbox list sliding up or down causes loss of check box status solution, androidlistview

Android listview + checkbox list sliding up or down causes loss of check box status solution, androidlistview

I used to have a headache for this problem for a long time. I am busy with other things. I haven't sorted it out all the time. Today I am not so busy. Let's take a look at the problem of listview + checkbox.

Interface:

Listview_cell:

The interface is very simple. A full screen listview, cell is very simple, a textview and a checkbox

Activity:

package com.example.testlistviewandcheckbox;import java.util.ArrayList;import java.util.List;import android.app.Activity;import android.content.Context;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.widget.Adapter;import android.widget.ListView;public class MainActivity extends Activity {private Context context;private ListView myListView;private List<String> list;private MyAdapter adapter;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);initView();}private void initView() {context = this;myListView = (ListView) findViewById(R.id.lv_test);list = new ArrayList<String>();for(int i=0;i<20;i++) {list.add("this is a title of:"+i);}adapter = new MyAdapter(context, list);myListView.setAdapter(adapter);}}

Adapter:

Package com. example. testlistviewandcheckbox; import java. util. hashMap; import java. util. list; import android. content. context; import android. view. view; import android. view. viewGroup; import android. widget. baseAdapter; import android. widget. checkBox; import android. widget. compoundButton; import android. widget. compoundButton. onCheckedChangeListener; import android. widget. textView; public class MyAdapter extends BaseAdapter {private Context context; private List <String> list; private HashMap <Integer, Boolean> tempMap; public MyAdapter (Context context, List <String> list) {this. context = context; this. list = list; tempMap = new HashMap <Integer, Boolean> (); for (int I = 0; I <list. size (); I ++) {// initialize the data. When it comes in, set every one to falsetempMap. put (I, false); // if it is not initialized, a null pointer will be reported. After all, if you have not saved anything, you will have to take it.} @ Overridepublic int getCount () {return list = null? 0: list. size () ;}@ Overridepublic String getItem (int position) {return list. get (position) ;}@ Overridepublic long getItemId (int position) {return position ;}@ Overridepublic View getView (final int position, View convertView, ViewGroup parent) {if (convertView = null) {viewHolder = new ViewHolder (); convertView = View. inflate (context, R. layout. listview_cell, null); viewHolder. TV _title = (TextView) convertView. findViewById (R. id. TV _title); viewHolder. cb_test = (CheckBox) convertView. findViewById (R. id. cb_test); convertView. setTag (viewHolder);} else {viewHolder = (ViewHolder) convertView. getTag ();} viewHolder. TV _title.setText (getItem (position); // Add a check listener for the checkbox and save the status of the checkbox at the current position into a HashMap viewHolder. cb_test.setOnCheckedChangeListener (new OnCheckedChangeListener () {@ Overridepublic void onCheckedChanged (CompoundButton buttonView, boolean isChecked) {tempMap. put (position, isChecked); // store the status of the current position}); // retrieves our status value from hashmap, then assign the value to the checkboxviewHolder at the corresponding position of the listview. cb_test.setChecked (tempMap. get (position); return convertView;} private ViewHolder viewHolder; public class ViewHolder {public TextView TV _title; public CheckBox cb_test ;}}

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