文本框電子郵件驗證

Question

喜有是，即時通訊試圖驗證一個文本框，使輸入了一定的電子郵件地址... 我複製別人的代碼，然後改變它適合我的程序問題IM。然而，即使輸入一個有效的電子郵件仍然是說無效的電子郵件條目

Private Sub EmailTextBox_Validating(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles EmailTextBox.Validating 
    Dim temp As String 
    temp = EmailTextBox.Text 
    Dim conditon As Boolean 
    emailaddresscheck(temp) 
    If emailaddresscheck(conditon) = False Then 
     MessageBox.Show("Please enter your email address correctly", "Incorrect Email Entry") 
     EmailTextBox.Text = "" 
     EmailTextBox.BackColor = Color.Blue 
    Else 
     EmailTextBox.BackColor = Color.Green 
    End If 

End Sub 


Private Function emailaddresscheck(ByVal emailaddress As String) As Boolean 
    Dim pattern As String = "^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$" 
    Dim emailAddressMatch As Match = Regex.Match(emailaddress, pattern) 
    If emailAddressMatch.Success Then 
     emailaddresscheck = True 
    Else 
     emailaddresscheck = False 
    End If 
End Function 

Private Sub EmailTextBox_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles EmailTextBox.TextChanged 
    EmailTextBox.BackColor = Color.White 
    Dim temp As String 
    temp = EmailTextBox.Text 
    Dim conditon As Boolean 
    emailaddresscheck(temp) 
    : If emailaddresscheck(conditon) = True Then 
     MessageBox.Show("Please enter your email address correctly", "Incorrect Email Entry") 
     EmailTextBox.Text = "" 
     EmailTextBox.BackColor = Color.Yellow 
    Else 
     EmailTextBox.BackColor = Color.Green 
    End If 
End Sub 

使用的顏色分別爲綠色和黃色，但我改變了箱子的顏色來識別人的問題是..盒子呈現藍色所以錯誤.. .im假設在這段代碼中很糟糕。

Private Function emailaddresscheck(ByVal emailaddress As String) As Boolean 
    Dim pattern As String = "^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$" 
    Dim emailAddressMatch As Match = Regex.Match(emailaddress, pattern) 
    If emailAddressMatch.Success Then 
     emailaddresscheck = True 
    Else 
     emailaddresscheck = False 
    End If 
End Function 

在此先感謝.. :) X

Answer 1

檢查下面的代碼，我改變了一點它

Private Sub TextBox1_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged 
     TextBox1.BackColor = Color.White 
     Dim temp As String 
     temp = TextBox1.Text 
     'Dim conditon As Boolean = False 
     If emailaddresscheck(temp) = True Then 
      ': If emailaddresscheck(conditon) = True Then 
      TextBox1.BackColor = Color.Green 
     Else 
      'MessageBox.Show("Please enter your email address correctly", "Incorrect Email Entry") 
      'TextBox1.Text = "" 
      TextBox1.BackColor = Color.Yellow 
     End If 

    End Sub 

我已經停止了郵件，因爲它永遠不會允許輸入有效的電子郵件，除非你複製並粘貼

也可以嘗試這種模式

Dim pattern As String = "\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*" 

Answer 2

一個簡單的方法來檢查，如果電子郵件地址是有效的是嘗試創建從它MailAddress：

Try 
    Dim testAddress = New MailAddress(email) 
Catch ex As FormatException 
    ' not a valid email address 
End Try 

Answer 3

你給的錯誤狀態消息框，否則你的代碼是正確的。 只需更改編碼如下。

If emailaddresscheck(conditon) = True Then 
      msgbox ("Correct email id") 
Else 
    MessageBox.Show("Please enter your email address correctly", "Incorrect Email Entry") 
    EmailTextBox.Text = "" 

End If 

參考：

Function EmailAddressCheck(ByVal emailAddress As String) As Boolean 

     Dim pattern As String = "^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$" 
     'Dim pattern As String = "\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*" 
     Dim emailAddressMatch As Match = Regex.Match(emailAddress, pattern) 
     If emailAddressMatch.Success Then 
      EmailAddressCheck = True 
     Else 
      EmailAddressCheck = False 
     End If 

End Function 

Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click 
     'EmailAddressCheck(TextBox6.Text) 
     If EmailAddressCheck(TextBox6.Text) = True Then 
      MessageBox.Show("Please enter your email address correctly", "Incorrect Email Entry") 
      TextBox6.Text = "" 
     Else 
      MsgBox("correct") 
     End If 
End Sub 

Answer 4

P

rivate Function validateEmail(ByVal Email As String) 
     Try 
      Dim myEmails As String() = Email.Split(",") 
      Dim isV As Boolean = True 
      For i As Integer = 0 To myEmails.Length - 1 
       ' Validate One by Ibe 
       isV = Global.ValidateEmail.IsValidEmail(myEmails(i).ToString) 
       If (isV = False) Then 
        Return False 
       End If 
      Next 
      Return isV 
     Catch ex As Exception 
     End Try 
    End Function 

1. 通過你的電子郵件地址字符串，這是簡單和容易。它會返回一個布爾值。