如何在列表视图（WPF）中实现是-否单选按钮？

Question

我有一个列表视图，其中有一个问题字段和两个单选按钮 - 是和否。我想将每个问题的响应添加到数据库中。我无法这样做。

这是我尝试过的-

部分 XAML 代码（列表视图位于堆栈面板内）-

<ListView HorizontalAlignment="Left" x:Name="listviewQue" Background="Azure" 
         ItemsSource="{Binding Questions}" ScrollViewer.CanContentScroll="False" SelectionMode="Multiple">
            <ListView.ItemTemplate>
                <DataTemplate>
                    <DockPanel>
                        <TextBlock DockPanel.Dock="Top" x:Name="quebox" Text="{Binding que_text}"
                 Style="{StaticResource ResourceKey=textblock_style }" />
                        <RadioButton GroupName="answergrp" Click="Yesradiobtn_Click" x:Name="yesradiobtn" DockPanel.Dock="Left">yes</RadioButton>
                        <RadioButton GroupName="answergrp" Click="Noradiobtn_Click" x:Name="noradiobtn" DockPanel.Dock="Right">no</RadioButton>
                    </DockPanel>


                </DataTemplate>
            </ListView.ItemTemplate>

        </ListView>

后面的代码：

private void Yesradiobtn_Click(object sender, RoutedEventArgs e)
        {
            string ans = "yes";
            Question q = new Question();
            q = listviewQue.SelectedItem as Question;
            string res = SQLiteDataAccess.AddResponse(surveryId, emp[empIndex].Id, q.que_id, ans);
            if (!(res == SQLiteDataAccess.SUCCESS))
            {
                MessageBox.Show("SQLite Exception for 'yes' radiobutton click " + res);
            }
        }

        private void Noradiobtn_Click(object sender, RoutedEventArgs e)
        {
            string ans = "no";
            Question q = new Question();
            q = listviewQue.SelectedItem as Question;
            string res = SQLiteDataAccess.AddResponse(surveryId, emp[empIndex].Id, q.que_id, ans);
            if (!(res == SQLiteDataAccess.SUCCESS))
            {
                MessageBox.Show("SQLite Exception for 'no' radiobutton click : " + res);
            }
        }

这是用于插入数据库的sqlite函数：

public static string AddResponse(string sid,string eid,int qid,string answer)
        {
            try
            {
                using (IDbConnection cnn = new SQLiteConnection(LoadConnectionString()))
                {
                    cnn.Execute("insert into RESPONSE values ('" + sid + "','" + eid + "'," + qid + ",'" + answer + "')");
                }
                return SUCCESS;
            }
            catch(Exception e)
            {
                return FAILURE +": exception e = "+e;
            }
        }

我得到的异常消息是 -

\System.NullReferenceException: 'Object reference not set to an instance of an object.'

q was null.

我怎样才能实现它？

更新问题类 -

namespace Version2._0
{
    public class Question
    {
        public int que_id { get; set; }
        public string que_text { get; set; }

        private bool isSelected;
        public bool IsSelected
        {
            get { return isSelected; }
            set
            {
                isSelected = value;
                 // SQLiteDataAccess.AddResponse(surveryId, emp[empIndex].Id, item.que_id, ans);
                // how can I get the surveyId and emp[empIndex].Id here
            }
        }
    }
}

Answer 1

这就是我解决它的方法，感谢@Clemens（非常感谢！） 我的问题课 -

public class Question
{
    public int que_id { get; set; }
    public string que_text { get; set; }
    public Boolean IsSelected { get; set; }
 }

我的 XAML 部分：

<ListView.ItemTemplate>
            <DataTemplate>
                <DockPanel>
                    <TextBlock DockPanel.Dock="Top" x:Name="quebox" Text="{Binding que_text}"
             Style="{StaticResource ResourceKey=textblock_style }" />
                    <RadioButton  IsChecked="{Binding IsSelected}" x:Name="yesradiobtn" DockPanel.Dock="Left">yes</RadioButton>
                    <RadioButton   x:Name="noradiobtn" DockPanel.Dock="Right">no</RadioButton>
                </DockPanel>
            </DataTemplate>
        </ListView.ItemTemplate>

在选择所有这样的答案后，我将通过单击按钮插入数据库-

private void Button_Click(object sender, RoutedEventArgs e)
    {
        List<Question> items = (List<Question>)listviewQue.ItemsSource;
        int count = 0;
        int totalcnt = items.Count;
        foreach (Question item in items)
        {
            if (item.IsSelectedRadioBtn)
            {
                count++;
                string ans = "yes";
                string res = SQLiteDataAccess.AddResponse(surveryId, emp[empIndex].Id, item.que_id, ans);
                if (!(res == SQLiteDataAccess.SUCCESS))
                {
                    MessageBox.Show("SQLite Exception for 'yes' radiobutton click " + res);
                }
            }
            else
            {
                count++;
                string ans = "no";
                string res = SQLiteDataAccess.AddResponse(surveryId, emp[empIndex].Id, item.que_id, ans);
                if (!(res == SQLiteDataAccess.SUCCESS))
                {
                    MessageBox.Show("SQLite Exception for 'no' button click " + res);
                }
            }
        }
        if (count != totalcnt)
        {
            MessageBox.Show("Please enter the response for all the questions");
        }
        else
        {
            MessageBox.Show("Response recorded successfully");
        }

    }