[RESOLVED] IsDate always returns false

Hi guys. Was wondering why the IsDate function always returns false.

Code:

---

dim myYear as string
myYear = trim(txtYear.text)

If isYear(myYear) = false then
msgbox("Not a year")
End if

---

Do I have to define the myYear variable of the date data type? Or is there some other problem?

If you want to determine whether the contents of a string is a valid date use Date.TryParse, ie

Code:

---

        Dim x As String = "12/02/2010"
        Dim dateresult As Date

        If Date.TryParse(x, dateresult) Then
            MessageBox.Show("Yes its a date")
        Else
            MessageBox.Show("No its not a date")
        End If

---

It doesn't seem to work for values that contain only a year.

Well a year isn't actually a date is it? Its just an integer.

What form of validation are you looking to do? Would you consider 35012 to be a year?

I wanted to make sure that the user inputs a valid date value, which I can also use to determine if the book is already outdated (eg: to check if the book was published 10 years or earlier from now). It's okay if I use an integer for it, but when I try to make a report using CR, it shows the Year Published value with a comma (eg: 2,010).

Quote:

---

It's okay if I use an integer for it, but when I try to make a report using CR, it shows the Year Published value with a comma (eg: 2,010).

---

In that case you need to change the formatting within CR. Unfortunately I can't really help you with that but it can't be that hard.

There is a control that might help. It is DateTimePicker.

Code:

---

    Private Sub DateTimePicker1_ValueChanged(ByVal sender As System.Object, _
                                            ByVal e As System.EventArgs) _
                                            Handles DateTimePicker1.ValueChanged
        'check selected date against past date
        If DateTime.Now.Date.AddYears(-10) > DateTimePicker1.Value.Date Then
            Stop
        End If
    End Sub

---

Quote:

---

Originally Posted by dbasnett

There is a control that might help. It is DateTimePicker.

Code:

---

    Private Sub DateTimePicker1_ValueChanged(ByVal sender As System.Object, _
                                            ByVal e As System.EventArgs) _
                                            Handles DateTimePicker1.ValueChanged
        'check selected date against past date
        If DateTime.Now.Date.AddYears(-10) > DateTimePicker1.Value.Date Then
            Stop
        End If
    End Sub

---

---

Yeah but the OP doesn't want a date as such - just a year. the DTP picks an actual date.

Code:

---

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        DateTimePicker1.CustomFormat = "yyyy"
        DateTimePicker1.Format = DateTimePickerFormat.Custom
        DateTimePicker1.ShowUpDown = True
    End Sub
    Private Sub DateTimePicker1_ValueChanged(ByVal sender As System.Object, _
                                            ByVal e As System.EventArgs) _
                                            Handles DateTimePicker1.ValueChanged
        'check selected date against past date
        If DateTime.Now.Date.AddYears(-10) > DateTimePicker1.Value.Date Then
            Stop
        End If
    End Sub

---