How to make a DateTimePicker increment/decrement on mouse wheel

Question

When you add a DateTimePicker control, you can select part of the control value (for example the month) and then use the up/down arrows to modify this part of the date/time value (for example, incrementing/decrementing the month).

What i would like to do is to allow the same thing with the mouse wheel. I tried to register on the event MouseWheel but I can't find a way to know which part of my date/time is currently selected, so I have no way to know if i should increment the time, the day, the month or the year.

Is there any way to do this ?

Answer 1

   dateTimePicker1.MouseWheel +=  new MouseEventHandler(dateTimePicker1_MouseWheel);

    private void dateTimePicker1_MouseWheel(object sender, System.Windows.Forms.MouseEventArgs e)
    {
        int incrementValue = SystemInformation.MouseWheelScrollLines;
        //Do increment
    }

Reference : http://msdn.microsoft.com/en-us/library/system.windows.forms.control.mousewheel.aspx

Answer 2

If you set the ShowUpDown property to True you get a spin box rather than a drop down and this modifies the highlighted portion of the date. Though I've just found out that this is irrelevant as the up and down arrow keys alter the highlighted portion of the date regardless of whether this property is set to true or not.

If you can find this code you should be able to get the mouse wheel to work as well. I'll take a look and see what I can find.

UPDATE:

I've just found this note about the ShowCheckBox property:

Read/write. If true, a checkbox is displayed to the left of the date-time value in the control. When this checkbox is checked, the values in the control can be changed by the user at runtime by highlighting a portion of the date and pressing the arrow keys. When not checked, the date can only be changed by clicking the drop-down menu to display the calendar. Default is false.

Is this of any use?

UPDATE 2:

I've not been able to find any code that deals with this particular aspect of the DateTimePicker. Don't Microsoft release the code to these sort of controls anymore?

Answer 3

Am not sure , but is this direction any good ..

Isnt it sure that , x coordinate for month < x for day < x for year (assuming no custom format) within the datepicker control , as its displayed along incresing x axis

then maybe we can capture the dateTimePicker1_MouseDown event and set the x coord where we clicked before the scroll in to a variable say:xCordOfClick , and then use this in Fiur's code for mousewheel to increment based on the difference in where we clicked and the x location of the datepicker .

something like

In dateTimePicker1_MouseDown(object sender, MouseEventArgs e)

    {
        xCordOfClick  = e.X;
    }

In mousewheel event

    {   
        //Do increment based on how far we clicked from the location of the control   
      // increment based on (xCordOfClick   - dateTimePicker1.Location.X).ToString() );
    }

Answer 4

A possible, but not quite elegant solution would be something like :

    private void dateTimePicker1_MouseWheel(object sender, System.Windows.Forms.MouseEventArgs e)
    {
        if (e.Delta > 0) System.Windows.Forms.SendKeys.Send("{UP}");
        else System.Windows.Forms.SendKeys.Send("{DOWN}");
    }

this should definitely work in general case, but some corner cases might have unexpected results (like having KeyUp/KeyDown events overriden)

Answer 5

I've tried to figure this one out too. In the end, I ended up with this:

Private Sub dtpDateTimePicker_MouseWheel(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
    If e.Delta > 0 Then
        SendKeys.Send("{Up}")
    Else
        SendKeys.Send("{Down}")
    End If
End Sub

You can automatically add this handler to all your date pickers in your form and it's containers using this method. Just call it once in form_load:

 Public Sub AttachDateTimeMouseWheels(ByRef ownerForm As Control)

    Dim myControl As Control        

    For Each myControl In ownerForm.Controls

        If TypeOf myControl Is DateTimePicker Then
            AddHandler myControl.MouseWheel, AddressOf dtpDateTimePicker_MouseWheel
        Else
            If myControl.Controls.Count > 0 Then
                AttachDateTimeMouseWheels(myControl)
            End If
        End If

    Next

End Sub