WPF DatePicker更改月份时引发异常 [英] WPF DatePicker throws exception when changing month

问题描述

好吧，我有一个正在WPF（Visual C＃2010 Express）中处理的项目，并且有一些绑定到DateTime属性的DatePicker。现在，如果我只是打开选择器并立即开始更改月份，就没有问题了。但是，如果我选择一个日期然后尝试更改月份，则会出现以下异常：

Ok I have this project I'm working on in WPF (Visual C# 2010 Express), and I have a few DatePickers that are bound to DateTime-properties. Now if I just open up the "picker" and start changing months immediately there is no problem. However, if I select a date and then try to change the month, I get the following Exception:

元素不存在或存在
已虚拟化；如果支持，则使用VirtualizedItem
模式。

Element does not exist or it is virtualized; use VirtualizedItem Pattern if it is supported.

堆栈跟踪仅显示：

[外部代码]

我的方法打开包含DatePickers的对话框（除其他外）

[外部代码]

[External Code]
my method that opens the dialog which contains the DatePickers (amongst other things)
[External Code]

如果属性为可空值，似乎没有什么不同，并且找不到一个结果

If the properties are nullable or not doesn't seem to make a difference, and can't find a single result on any of the major search engines on the above exception.

XAML

<Window x:Class="WpfApplication1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525" Loaded="Window_Loaded">
    <Grid>
        <DatePicker SelectedDate="{Binding TheDate}" 
                    x:Name="datePicker1" />
        <Button Content="Button"
                x:Name="button1" 
                Click="button1_Click" />
    </Grid>
</Window>

隐藏代码

    class TheClass
    {
        public DateTime TheDate { get; set; }
    }

    public MainWindow()
    {
        theClass = new TheClass();
        theClass.TheDate = DateTime.Now;

        InitializeComponent();
    }

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        this.DataContext = theClass;
    }

    private void button1_Click(object sender, RoutedEventArgs e)
    {
        System.Windows.MessageBox.Show(theClass.TheDate.ToString());
    }

任何人以前见过这种行为或有其他想法吗？我距离WPF专家还很遥远，并且说实话也不知道是什么原因或从哪里开始寻找。.

Anyone ever seen this behaviour before or have any other ideas? I'm far from a WPF-expert and have honestly no idea what might be causing this or where to start looking..

推荐答案

我希望这可能只是评论而不是答案，但可以这样：

I wish this could be a comment and not an answer but here goes:

http://www.switchonthecode.com/tutorials/wpf-snippet-detecting-binding-errors

给出读段，如果这是您遇到的问题，它应该报告任何绑定错误。

Give that a read and it should report any binding errors if that is the issue in your case.

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