对于那个问题，我做了一个最小的项目让每个人都体验这种行为。我希望它不只是在我这样运行的引擎上。
在我的项目中，我实现了一个包含大量示例数据的列表框。列表框也有每个项目的复选框元素。
问题：首先我选中/取消选中列表框中的复选框。然后我在列表框中滚动了几次。现在我注意到很多复选框被随机选中/取消选中。如果我将 ListBox 剪掉一点（参见源代码中的注释），就不会出现奇怪的行为。编辑:: 如果您没有这个问题，请尝试检查列表最底部的项目。也许您必须使用更多对象扩展列表才能看到问题。
这里有一些代码片段。如您所见，我已经尝试使用 List/ObservableCollection、PropertyChanged 和 LongListSelector 而不是 Listbox。
C＃
// Already tried to use simple List<SampleCheckedData> buildings.
// Doesnt change anything.
private ObservableCollection<SampleCheckedData> buildings;
// Already tried with this as well.
/*protected ObservableCollection<SampleCheckedData> Buildings
{
get
{
return buildings;
}
set
{
buildings = value;
}
}*/
public MainPage()
{
InitializeComponent();
buildings = new ObservableCollection<SampleCheckedData>();
buildings.Add(new SampleCheckedData() { Name = "Cloudy", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Sun", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Drizzle", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Snow", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Cloudy", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Sun", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Drizzle", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Snow", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Cloudy", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Sun", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Cloudy", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Sun", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Drizzle", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Snow", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Cloudy", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Sun", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Cloudy", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Sun", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Drizzle", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Snow", IsChecked = false });
// If you comment this data out, the listbox is smaller and no problem occurs in my case.
buildings.Add(new SampleCheckedData() { Name = "Cloudy" , IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Sun", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Cloudy", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Sun", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Drizzle", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Snow", IsChecked = false });
// If you comment this data out, the listbox is smaller and no problem occurs in my case. [END]
this.listBox2.ItemsSource = buildings;
}
我的选中/取消选中事件：
private void CheckBox_Checked(object sender, RoutedEventArgs e)
{
//Use this if you use the LongListSelector.
//ListBoxItem checedItem = this.listBox2.SelectedItem as ListBoxItem;
ListBoxItem checedItem = this.listBox2.ItemContainerGenerator.ContainerFromItem((sender as CheckBox).DataContext) as ListBoxItem;
if (checedItem != null)
{
checedItem.IsSelected = true;
}
}
private void CheckBox_Unchecked(object sender, RoutedEventArgs e)
{
//Use this if you use the LongListSelector.
//ListBoxItem checedItem = this.listBox2.SelectedItem as ListBoxItem;
ListBoxItem checedItem = this.listBox2.ItemContainerGenerator.ContainerFromItem((sender as CheckBox).DataContext) as ListBoxItem;
if (checedItem != null)
{
checedItem.IsSelected = false;
}
}
还有我的简单数据类：
public class SampleCheckedData
{
//Already tried with this, but it is not working.
/*
private bool _isChecked;
public bool IsChecked
{
get { return _isChecked; }
set
{
if (_isChecked != value)
{
_isChecked = value;
NotifyPropertyChanged("IsChecked");
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(String info)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(info));
}
}
*/
public bool IsChecked
{
get;
set;
}
public string Name
{
get;
set;
}
}
XAML
我的内容如下所示：
<!--ContentPanel - zusätzliche Inhalte hier platzieren-->
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<ListBox x:Name="listBox2" SelectionMode="Multiple">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding IsChecked}" Checked="CheckBox_Checked" Unchecked="CheckBox_Unchecked"/>
<TextBlock Text="{Binding Name}" Width="150" VerticalAlignment="Center"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<!--//Use this if you use the LongListSelector.-->
<!--<toolkit:LongListSelector x:Name="listBox2" Background="Transparent" IsFlatList="True" ItemTemplate="{StaticResource citiesItemTemplate}" />-->
</Grid>
如果您想使用 LongListSelector 进行尝试，则可选，包括：
<DataTemplate x:Key="citiesItemTemplate">
<StackPanel Grid.Column="1" VerticalAlignment="Top">
<TextBlock Text="{Binding Name}" FontSize="26" Margin="12,-12,12,6"/>
<CheckBox IsChecked="{Binding IsChecked}" Checked="CheckBox_Checked" Unchecked="CheckBox_Unchecked"/>
</StackPanel>
</DataTemplate>
和xmlns:toolkit="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls.Toolkit"
我希望有人能解决这个问题。没有找到任何线索...
编辑：
相关问题：
编辑：
我注意到您必须在列表中添加更多 eobjects 才能出现此问题：
buildings.Add(new SampleCheckedData() { Name = "Cloudy", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Sun", IsChecked = false });
buildings.Add(new SampleCheckedData() { Name = "Cloudy", IsChecked = false });
.....
然后，当您检查列表顶部或底部的项目时，就会出现问题。