Question

I make a program on Windows7 with VB.NET 2008 which uses dates and datetime pickers which work’s good.

Like this:

    With dtp_date1

        'here crashes
        .Text = DateTime.Now.Date.ToString("dd.MM.yyyy.") & " 00:00:00"

        .Format = DateTimePickerFormat.Custom
        .CustomFormat = "dd.MM.yyyy. HH:mm:ss tt"
        .ShowUpDown = False
    End With

    With dtp_date2
        .Text = DateTime.Now.Date.ToString("dd.MM.yyyy.") & " 23:59:59.9999"
        .Format = DateTimePickerFormat.Custom
        .CustomFormat = "dd.MM.yyyy. HH:mm:ss tt"
        .ShowUpDown = False
    End With

This works OK untill I put this program to windows XP.
Error appears:

string was not recognized as a valid Datetime

I try to fix this so:

.Text = CDate(DateTimeNow.Date.ToString("dd.MM.yyyy.") & " 00:00:00").ToString

And here get error:

Conversion from string “06.01.2013. 00.00.00” to type ‘Date’ is not valid.

Since I have many places in program with dates what to do to fix this error?

Answer 1

Never assign the DateTimePicker.Text property. You’ll get slammed if the format of your string doesn’t match the culture or the Control Panel overrides for the date/time format.

Always use the DateTimePicker.Value property. A property of type DateTime, immune to format problems. Fix:

    Dim now = DateTime.Now.Date
    dtp_date1.Value = now
    dtp_date2.Value = now.AddDays(1) - new TimeSpan(1)