[最少的项目提供]在列表框和复选框大量数据的奇怪行为 [英] Strange behaviour with a lot of data in ListBox and Checkbox [minimal project provided]
问题描述
有关这个问题我做了一个最小的项目给大家遇到此行为。我希望这不只是对我的引擎上运行这样。
For that problem I made a minimal project for everyone to experience this behaviour. I hope it is not just on my engine running like this.
在项目中，我实现了一大把样本数据的列表框。列表框对每个项目的复选框元素为好。
In my project I realized a listbox with a a lot of sample data. The listbox has a checkbox element for each item as well.
问题：首先我检查/在我的列表框中取消选中复选框。然后，我通过我的列表框滚动几次。现在我发现了很多的复选框得到选中/取消随机。如果我剪了一个ListBox中位向下（见源代码注释）有没有奇怪的行为。:如果你没有这个问题，尝试在列表的底部检查项目。也许你要多带些对象扩展列表中看到的问题。
The problem: First I check/uncheck checkboxes in my listbox. Then I scroll several times through my listbox. Now I notice that a lot of checkboxes get checked/unchecked randomly. If I cut the ListBox a bit down (see comments in source code) there is no strange behaviour. : If you dont have this problem, try to check items at the very bottom of the list. Maybe you have to extend the list with some more objects to see the problem.
下面的一些代码段。正如你可以看到我已经在列表/的ObservableCollection，PropertyChanged的和LongListSelector而不是列表框试了一下。
Here some code snippets. As you can see I already tried it with List/ObservableCollection, PropertyChanged and LongListSelector instead of 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;
}
我选中/清除事件：
My check/uncheck events:
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;
}
}
和我smple数据类：
And my smple data class:
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
我的内容是这样的：
<!--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>
如果你想与LongListSelector试试可选包括：
Optional if you want to try it with LongListSelector include:
<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>
和的xmlns：工具=CLR的命名空间：Microsoft.Phone.Controls ;装配= Microsoft.Phone.Controls.Toolkit
我希望有人能解决这个问题。没有找到任何线索......
I hope someone can solve this. Didnt find any clues...
编辑：
相关问题：
编辑：
我注意到，你必须在列表中添加一些铁道部eobjects有这个问题
I noticed that you have to add some mor eobjects in the list to have this problem:
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，当你在顶部或底部的检查项目名单，出现问题。
Then, when you check items at the very top or bottom of the list, the problem occurs.
推荐答案
您永远保存复选框的选中状态。修复您的XAML：
You never save the selected state of the checkbox. Fix your XAML:
<复选框器isChecked ={结合器isChecked，模式=双向}选中=CheckBox_Checked未选中=CheckBox_Unchecked />
这篇关于[最少的项目提供]在列表框和复选框大量数据的奇怪行为的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
