嘿,我正在使用MVVM模式在Windows Phone 8.1中开发一个应用程序.我想从viewModel的DateChanged事件上的DatePicker获取日期.
运行程序后,我得到此错误：

A first chance exception of type ‘Windows.UI.Xaml.Markup.XamlParseException’ occurred in App1.exe WinRT
information: Cannot add instance of type ‘%0’ to a collection of type
‘%1’. [Line: 117 Position: 97] An exception of type
‘Windows.UI.Xaml.Markup.XamlParseException’ occurred in App1.exe but
was not handled in user code WinRT information: Cannot add instance of
type ‘%0’ to a collection of type ‘%1’. [Line: 117 Position: 97]
Additional information: The text associated with this error code could
not be found.

我的看法是：

<DatePicker Grid.Row="1" Grid.Column="1"
                VerticalContentAlignment="Center"
                HorizontalContentAlignment="Center"
                HorizontalAlignment="Left"
                VerticalAlignment="Center" Margin="26,-0.333,0,0.5"
                Date="{Binding Dates, Mode=TwoWay}">
        <i:Interaction.Behaviors>
            <core:EventTriggerBehavior EventName="DateChanged">
                <core:InvokeCommandAction Command="{Binding InitializeExpenseListCommand}"/>
            </core:EventTriggerBehavior>
        </i:Interaction.Behaviors>
    </DatePicker>

和viewModel：

    public MainViewModel()
    {
        _dates = new DateTimeOffset(DateTime.Now);
    }

    private DateTimeOffset _dates;
    public DateTimeOffset Dates
    {
        get { return _dates; }
        set
        {
            _dates = value;
            RaisePropertyChanged();
        }
    }
    public ICommand InitializeExpenseListCommand
    {
        get { return new RelayCommand(InitializeExpenseList()); }
    }

    public Action InitializeExpenseList()
    {
        return () => Debug.WriteLine(_dates);
    }

谁能帮助我解决这个错误？

解决方法:

如果您尝试添加的事件不存在或EventTriggerBehaviour不支持,则我的回答可能有点晚,但是会出现此错误(仍然)(在WinRT 8.1中消息中仍带有占位符！).支持的事件包括：轻击,PointerPressed,已加载,DataContextChanged,Click,选中,未选中,SelectionChanged,TextChanged,Toggled,NavigationCompleted

查看https://msdn.microsoft.com/en-us/library/windows/apps/dn469361.aspx