VB.Net/Language Basics/Integer Parser — различия между версиями
Admin (обсуждение | вклад) м (1 версия) |
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(нет различий)
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Текущая версия на 15:42, 26 мая 2010
Validate an Integer
<source lang="vbnet"> Imports System Public Class MainClass
Shared Sub Main(ByVal args As String()) Dim num_items As Integer If Not IsValidInteger(num_items, "00", 1, 100) Then Exit Sub End Sub
Shared Private Function IsValidInteger(ByRef result As Integer, _ ByVal txt As String, ByVal field_name As String, _ Optional ByVal min_value As Integer = Integer.MinValue, _ Optional ByVal max_value As Integer = Integer.MaxValue) As Boolean " Check for blank entry. If txt.Length < 1 Then Console.WriteLine("Please enter " & field_name & ".") Return False End If " See if it"s numeric. If Not IsNumeric(txt) Then Console.WriteLine(field_name & " must be a number.") Return False End If " Assign the value. Try result = Integer.Parse(txt) Catch ex As Exception Console.WriteLine("Error in " & field_name & "." & _ vbCrLf & ex.Message) Return False End Try " Check that the value is between min_value and max_value. If result < min_value Or result > max_value Then Console.WriteLine(field_name & " must be between " & _ min_value.ToString & " and " & max_value.ToString & ".") Return False End If " The value is okay. Return True End Function
End Class
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