How to place cursor in the first position of a Datepicker control in C#?

Question

I have a datepicker control on a wpf form (masked as 00-00-0000). If the datepicker is empty, then I want the cursor always to be in the first position no matter where I click on the datepicker textbox. I tried using SelectionStart property (set to 0) on MouseDown event but it didn't work. Can anyone please give an idea? Please let me know if you need more info. Any help is much appreciated. Thanks!

Answer 1

You should find TextBox element and subscribe to event PreviewMouseUp.

1) Add DatePicker with Loaded event:

<DatePicker Name="myDatePicker" Loaded="MyDatePicker_OnLoaded" /> 

2) Find TextBox element (in the DatePicker type of the text box element is DatePickerTextBox) and subscribe to PreviewMouseUp:

private void MyDatePicker_OnLoaded(object sender, RoutedEventArgs e)
{
    var tb = (DatePickerTextBox)myDatePicker.Template.FindName("PART_TextBox", myDatePicker);
    if (tb != null)
    {
        tb.PreviewMouseUp += (s, args) =>
        {
            tb.CaretIndex = 0;
        };
    }
}