访问和控制自定义ListBoxItem控件

本文关键字：ListBoxItem 控件 自定义 控制 访问 | 更新日期: 2023-09-27 18:23:35

我有一个列表框，用于解析XML文件中的信息。我为我的ListBoxItems创建了一个自定义用户控件，它包括一个复选框和一个保存人名的文本块。我的问题是，我无法访问和控制代码中自定义ListBoxItem用户控件的控件。我不知道如何访问它们。我想通过按钮的点击事件来删除未检查的名称，并将已检查的名称保存到IsolatedStorage中的文件中。我还没有保存数据，因为我想先让基本的"选定复选框标识"工作。你能帮我吗？

这是代码：

    public partial class OppilasLista : PhoneApplicationPage
    {
        XDocument lista = XDocument.Load("NykyisetKurssit.xml");
        XDocument oppilasInfo = XDocument.Load("Oppilaat.xml");
        string id = string.Empty;
        public OppilasLista()
        {
            InitializeComponent();
        }
        protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
        {
            if (NavigationContext.QueryString.TryGetValue("id", out id))
            {
                var ryhma = (from ryhmaInfo in lista.Descendants("Kurssi")
                             where ryhmaInfo.Attribute("id").Value == id
                             select new Kurssit
                             {
                                 RyhmanNimi = (string)ryhmaInfo.Element("tunnus").Value
                             }).FirstOrDefault();
                PageTitle.Text = ryhma.RyhmanNimi;
                var oppilas = (from oppilaat in oppilasInfo.Descendants("Oppilas")
                               where oppilaat.Attribute("ryhma").Value == id
                               select new Kurssit
                               {
                                   OppilaanNimi = (string)oppilaat.Element("nimi").Value
                               });
                oppilaidenLista.ItemsSource = oppilas;
            }
            base.OnNavigatedTo(e);
        }
        private void Tallenna_Button_Click(object sender, RoutedEventArgs e)
        {
        }
    }

和XAML

    <!--LayoutRoot is the root grid where all page content is placed-->
    <Grid x:Name="LayoutRoot" Background="Transparent">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <!--TitlePanel contains the name of the application and page title-->
        <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
            <TextBlock x:Name="ApplicationTitle" Text="LÄSNÄOLOT" Style="{StaticResource PhoneTextNormalStyle}"/>
            <TextBlock x:Name="PageTitle" Text="{Binding RyhmanNimi}" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
        </StackPanel>
        <!--ContentPanel - place additional content here-->
        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
            <ListBox ItemsSource="{Binding}" x:Name="oppilaidenLista" Margin="0,0" Height="500" VerticalAlignment="Top" d:LayoutOverrides="VerticalAlignment">
                <ListBox.ItemTemplate>
                    <DataTemplate>
                        <local:ListboxItem />
                    </DataTemplate>
                </ListBox.ItemTemplate>
            </ListBox>
            <Button Content="Tallenna" Height="72" HorizontalAlignment="Left" Margin="12,506,0,0" Name="tallennaButton" VerticalAlignment="Top" Width="438" Click="Tallenna_Button_Click" />
        </Grid>
    </Grid>

AND自定义ListBoxItem控件

    <Grid x:Name="LayoutRoot">
        <CheckBox Height="72" HorizontalAlignment="Left" Margin="0,7,0,0" Name="checkBox" VerticalAlignment="Top" />
        <TextBlock Height="55" HorizontalAlignment="Left" Margin="74,12,0,0" Name="studentName" Text= "{Binding OppilaanNimi}" VerticalAlignment="Top" Width="394" FontSize="40" />
    </Grid>

访问和控制自定义ListBoxItem控件

我建议您将ListBox绑定到一个具有布尔属性的项集合，您可以将CheckBox的IsChecked属性绑定到该集合；

public class Kurssit : INotifyPropertyChanged {
  private string _Oppilaanimi;
  private bool _IsChecked;
  public string OppilaanNimi {
    get { return _Oppilaanimi; }
    set {
      if (_Oppilaanimi != value) {
        _Oppilaanimi = value;
        PropertyChanged(this, new PropertyChangedEventArgs("OppilaanNimi"));
      }
  }
  public bool IsChecked {
    get { return _IsChecked ; }
    set {
      if (_IsChecked != value) {
        _IsChecked = value;
        PropertyChanged(this, new PropertyChangedEventArgs("IsChecked"));
      }
  }
  public event PropertyChangedEventHandler PropertyChanged;
}

在LINQ语句中创建这些项时，将它们存储在成员变量中，例如private ObservableCollection<Kurssit> _Kurssit。

然后将您的ListBox绑定到此成员变量；

oppilaidenLista.ItemsSource = _Kurssit;

然后将您的自定义ListBoxItem控件更改为更像；

<Grid x:Name="LayoutRoot">
    <CheckBox IsChecked="{Binding IsChecked}" Height="72" HorizontalAlignment="Left" Margin="0,7,0,0" Name="checkBox" VerticalAlignment="Top" />
    <TextBlock Height="55" HorizontalAlignment="Left" Margin="74,12,0,0" Name="studentName" Text= "{Binding OppilaanNimi}" VerticalAlignment="Top" Width="394" FontSize="40" />
</Grid>

然后在按钮的点击处理程序中；

private void Tallenna_Button_Click(object sender, RoutedEventArgs e)
{
  List<Kurssit> selected = _Kurssit.Where(x => x.IsSelected == true).ToList()
  // You can now operate manipulate this sublist as needed
  // ie. Save this subset of items to IsolatedStorage
  //     Or remove the items from the original _Kurssit collection... whatever :)
}

注意：因为在本例中绑定的成员变量也是ObservableCollection｛T｝类型，调用Add()、Remove()等将引发事件，ListBox将根据需要对这些添加/删除这些项的UI控件做出响应。

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