FrameworkElementFactory的正确DatePicker SelectedDateChangedEven

Question

我正在DataGrid控件中创建绑定DatePicker控件列。对于每个DatePicker控件，我想附加一个SelectedDateChangedEvent处理程序，但我很难做到这一点。

考虑以下WPF代码:

private void dg_AutoGeneratingColumn(object sender, DataGridAutoGeneratingColumnEventArgs e)
{
    if (e.PropertyName == "Event Date")
    {
        var f = new FrameworkElementFactory(typeof(DatePicker));
         ...
        // I tried this:
        //f.AddHandler(DatePicker.SelectedDateChangedEvent, new RoutedEventHandler(aRoutedEventHandler));
        // and I tried this:
        //f.AddHandler(DatePicker.SelectedDateChangedEvent, new SelectionChangedEventHandler(aSelectionChangedEventHandler));
        e.Column = new DataGridTemplateColumn()
        {
            Header = e.Column.Header,
            CellTemplate = new DataTemplate() { VisualTree = f },
        };
    }
}
private void aRoutedEventHandler(object sender, RoutedEventArgs e)   { ... }
private void aSelectionChangedEventHandler(object sender, SelectionChangedEventArgs e) {...}

尝试任何一个事件处理程序都会导致"参数异常":

类型为'System '的第一次异常。在PresentationFramework.dll中发生了ArgumentException附加信息:处理程序类型无效。

正确的处理程序是什么?

Answer 1

您需要为DatePicker SelectedDateChangedEvent添加如下处理程序

f.AddHandler(DatePicker.SelectedDateChangedEvent, new EventHandler<SelectionChangedEventArgs>(aSelectionChangedEventHandler));

处理程序类型可以通过查看声明的公共事件中的DatePicker类来找到

public event RoutedEventHandler CalendarOpened;
public event RoutedEventHandler CalendarOpened;
public event EventHandler<DatePickerDateValidationErrorEventArgs> 
public event EventHandler<SelectionChangedEventArgs> SelectedDateChanged;