Check Values in an Array if Null: VB.NET

Check Values in an Array if Null

Asked by: Arka3L

I'm trying to simplify my coding by putting all of my requirements in ONE potential line of code instead of assigning if functions to each silly variable i have, which leads me to my question.

I have a UI with text boxes, some of which can be left empty, some which cannot. What I'm looking for is a way to add an array containing those variables that cannot be empty, and if this is possible, for the program to check each variable (text box) for any indication that it's null, if so, throw up a msgbox stating the exact box which is empty before it writes anything to the db.

I'm currently working with a few basic text boxes. FirstName, LastName, DOB, Address, PhoneNumber.

Any help would be greatly appreciated!!

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Public Class Form3 Private RequiredEntries() As String = {"LastName", "DOB", "PhoneNumber"} Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim tb As TextBox Dim ctl As Control For Each ctlName As String In RequiredEntries ctl = GetControlByName(ctlName) If Not IsNothing(ctl) AndAlso TypeOf ctl Is TextBox Then tb = DirectCast(ctl, TextBox) If tb.Text.Trim.Length = 0 Then MessageBox.Show(ctlName, "Missing Entry", MessageBoxButtons.OK, MessageBoxIcon.Exclamation) tb.Focus() Exit Sub End If End If Next ' ...if you get here then the TextBoxes have been properly filled out... MessageBox.Show("All Required Entries have been Filled Out") End Sub Private Function GetControlByName(ByVal ctlName As String) As Control Dim matches() As Control = Me.Controls.Find(ctlName, True) If matches.Length > 0 Then Return matches(0) Else Return Nothing End If End Function End Class

Again, lots of ways to do it...here is one:

Public Class Form1
 
    Private RequiredFields As New Dictionary(Of String, String)
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim values() As String
        Dim RequiredEntries As String = "LastName,Last Name|DOB,Date of Birth|PhoneNumber,Phone Number"
        For Each pair As String In RequiredEntries.Split("|")
            values = pair.Split(",")
            RequiredFields.Add(values(0), values(1))
        Next
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim tb As TextBox
        Dim ctl As Control
        For Each ctlName As String In RequiredFields.Keys
            ctl = GetControlByName(ctlName)
            If Not IsNothing(ctl) AndAlso TypeOf ctl Is TextBox Then
                tb = DirectCast(ctl, TextBox)
                If tb.Text.Trim.Length = 0 Then
                    Dim msg As String = RequiredFields.Item(ctlName)
                    MessageBox.Show(msg, "Missing Entry", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
                    tb.Focus()
                    Exit Sub
                End If
            End If
        Next
 
        ' ...if you get here then the TextBoxes have been properly filled out...
        MessageBox.Show("All Required Entries have been Filled Out")
    End Sub
 
    Private Function GetControlByName(ByVal ctlName As String) As Control
        Dim matches() As Control = Me.Controls.Find(ctlName, True)
        If matches.Length > 0 Then
            Return matches(0)
        Else
            Return Nothing
        End If
    End Function
 
End Class

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Check Values in an Array if Null

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VB.NET

.NET

Microsoft Visual Basic.Net

Visual Basic Programming

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