在设计时从vb.net的另一种形式引用UserControl的组成TextBox

Question

Right up front, I'm writing in vb code, not c#.

I've checked out the suggested forum subjects and none apply,(that I could find) so here it is. I'm relatively new to vb.net. (come from vb6)

I'm creating a user control_1 which contains textboxes and a button. Control_1 inherits from another user control_2 (a few textboxes and the calendar form button). When I press the button it launches a Calendar form containing a CalendarControl .

Works fine so far.

Now I need to return the CalendarControl value on it's Calendar form back to the unseated user control_1 . I am talking design time here, User Control_1 is not seated on a form yet.

I do not want to trigger the calendar form from it seated form because I want this proccess to be encapsulated.

I wrote the code as a forms based app to make sure my logic and app worked. Now I'm trying to move the code and constituent controls into a control library.

I've tried calling Usercontrol_1 from my calendar form but it does not show any of my shared controls or properties. I've tried Me.Parent.Controls in a For Each loop. It found the controls but said I needed to use the New keyword. I tried new and it didn't work. Maybe I misunderstood what the intellisence was talking about.

Thanks in advance for your time and help.

Answer 1

At design time you cannot click a button which opens another form. Therefore I am really not sure what you are trying to achieve at design time.

I don't know the calender control you are using. Therefore I going to explain a possible solution using a DateTimePicker . On the calender form (let's call it fdlgCalender add a property that allows accessing the selected date of the calender control publicly:

Public Property SelectedDate() As Date
    Get
        Return DateTimePicker1.Value
    End Get
    Set(ByVal value As Date)
        DateTimePicker1.Value = value
    End Set
End Property

On your UserControl containing the calender button, create a similar property. This time we are using a nullable date in order to indicate the situation where no date has been selected

Public Property SelectedDate As Date?

Now you can call the calender form like this:

Dim fdlg As New fdlgCalender()
If SelectedDate.HasValue Then
    fdlg.SelectedDate = SelectedDate.Value
Else
    fdlg.SelectedDate = Today
End If

' Assuming that the dialog form sets the `DialogResult` correctly
If fdlg.ShowDialog() = DialogResult.OK Then
    SelectedDate = fdlg.SelectedDate
Else
    SelectedDate = Nothing
End If

Now you can access the date from outside of your user control through the SelectedDate property.

(The code is not tested)