如何为列表视图适配器中的开关添加点击监听器

Posted 2023-04-19

【中文标题】如何为列表视图适配器中的开关添加点击监听器

【英文标题】：how to add click listener for a switch in listview adapter

【发布时间】：2021-07-09 08:25:44

【问题描述】：

我有一个带有适配器的列表视图，列表视图项目是线性布局，带有包含随机数的开关，如何为开关编写点击监听器？

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_
    android:layout_
    android:orientation="vertical">
    <ListView
        android:id="@+id/lster"
        android:layout_
        android:layout_
        android:layout_margin="10dp">
    </ListView>
</LinearLayout>

MainActivity.java

package com.kattah.myapplication;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Random;
public class MainActivity extends AppCompatActivity 
    ListView lv;
    myadapter adp;
    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ArrayList<HashMap<String, String>> RandomNumbberList = new ArrayList<>();
        int i;
        i = 0;
        while (i < 10) 
            HashMap<String, String> RandomElement = new HashMap<>();
            int rnd = new Random().nextInt(100000);
            String num = String.valueOf(rnd);
            RandomElement.put("number", num);
            RandomNumbberList.add(RandomElement);
            i = i + 1;
        
        ArrayList<String> items;
        items = new ArrayList<String>();
        String currentrow;
        for (int u = 0; u < RandomNumbberList.size(); u++) 
            currentrow = RandomNumbberList.get(u).toString();
            items.add(currentrow);
        
        lv = findViewById(R.id.lster);
        adp = new myadapter(this, R.layout.list_row2, items, lv);
        lv.setAdapter(adp);
    

list_row2.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_
    android:layout_
    android:orientation="vertical"
    android:descendantFocusability="blocksDescendants"
    android:padding="5dip">
        <Switch
            android:id="@+id/switch1"
            android:layout_
            android:layout_
            android:text="Switch"
            android:textSize="16sp" />
</LinearLayout>

myadapter.java

package com.kattah.myapplication;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.CompoundButton;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.Switch;
import android.widget.Toast;
import java.util.List;
/**
 * Created by Vikram Diwakar on 1/23/2018.
 */
public class myadapter extends ArrayAdapter<String> 
    //the list values in the List of type hero
    List<String> items;
    //activity context
    Context context;
    //the layout resource file for the list items
    int resource;
    ListView lsst;
    //constructor initializing the values
    public myadapter(Context context, int resource, List<String> items, ListView lss) 
        super(context, resource, items);
        this.context = context;
        this.resource = resource;
        this.items = items;
        lsst = lss;
    
    //this will return the ListView Item as a View
    @Override
    public View getView(final int position, View convertView, ViewGroup parent) 
        //we need to get the view of the xml for our list item
        //And for this we need a layoutinflater
        LayoutInflater layoutInflater = LayoutInflater.from(context);
        //getting the view
        View view = layoutInflater.inflate(resource, null, false);
        Switch sw = (Switch) view.findViewById(R.id.switch1);
        // Get the text from the list and split it to get the random number
        String s = items.get(position);
        s = s.replace("", "");
        s = s.replace("", "");
        String str[] = s.split(",");
        String s1[] = str[0].split("=");
        sw.setText(s1[1]);
        sw.setTag(position);
        sw.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() 
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) 
                if (isChecked == true) 
                    TerminalAdapter adpr = (TerminalAdapter) lsst.getAdapter();
                    final int firstListItemPosition = lsst.getFirstVisiblePosition();
                    final int lastListItemPosition = firstListItemPosition + lsst.getChildCount() - 1;
                    for (int i = firstListItemPosition; i <= lastListItemPosition; i++) 

                        LinearLayout ln;
                        ln = (LinearLayout) getViewByPosition(i, lsst);
                        Switch swth;
                        swth = (Switch) ln.getChildAt(0);

                        if (swth != buttonView) 
                            swth.setChecked(false);
                        
                        ;

                    
                
        );
        return view;
    
public View getViewByPosition(int pos, ListView listView) 
        final int firstListItemPosition = listView.getFirstVisiblePosition();
        final int lastListItemPosition = firstListItemPosition + listView.getChildCount() - 1;

        if (pos < firstListItemPosition || pos > lastListItemPosition) 
            return listView.getAdapter().getView(pos, null, listView);
         else 
            final int childIndex = pos - firstListItemPosition;
            return listView.getChildAt(childIndex);
        
    

我想知道将代码放在哪里以及如何访问列表视图中的所有开关。

【问题讨论】：

您已经有代码来响应适配器中的onCheckedChanged() 回调。究竟是什么问题？

无法访问开关按钮。

对不起，问题不是很清楚，我已经编辑了帖子。我的问题是在选择一个开关并打开时关闭所有开关。如何到达其余的开关？？

数据在适配器中（在items中）。在适配器中，您可以访问这些。

现在我再次编辑了帖子，我在适配器中添加了一个公共视图 getViewByPosition，它可以通过它的位置获取视图，我尝试检查所有开关以关闭它们。当所选的开关打开时，也不起作用。 span>

【参考方案1】：

已通过上次编辑解决！检查上面的完整代码。