鴨爸的隨手寫寫

每次查Regular Expression查完就忘了

乾脆記下來好了....

判斷如果輸入不為數字 Return true

.NET內建的IsNumeric

會接受","當作千位分隔符號

"+"與"-"當作正負號

字串含有"."當作小數點

"e"當作科學符號

括弧、與八進制和十六進制的數值字串

所以就選用判斷式了

Private Sub txtStr1_Leave(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtStr1.Leave
     If CheckNumber(txtStr1.Text) = True Then           
         txtStr1.Focus()
     End If
End Sub

Public Function CheckNumber(ByVal keyChar) As Boolean
   If System.Text.RegularExpressions.Regex.IsMatch(keyChar.ToString(), "[^0-9]") Then
       MessageBox.Show("請輸入數字")
       Return True
   Else
       Return False
   End If
End Function

第二種方式感覺落落長指接去抓keyboard：

Private Sub txtStr1_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtStr1.KeyPress
    'e.KeyChar == (Char)48 ~ 57 -----> 0~9 
    'e.KeyChar == (Char)8  -----------> Backpace 
    'e.KeyChar == (Char)13 -----------> Enter 
    If e.KeyChar = Chr(48) Or _
    e.KeyChar = Chr(49) Or _
    e.KeyChar = Chr(50) Or _
    e.KeyChar = Chr(51) Or _
    e.KeyChar = Chr(52) Or _
    e.KeyChar = Chr(53) Or _
    e.KeyChar = Chr(54) Or _
    e.KeyChar = Chr(55) Or _
    e.KeyChar = Chr(56) Or _
    e.KeyChar = Chr(57) Or _
    e.KeyChar = Chr(13) Or _
    e.KeyChar = Chr(8) Then
        e.Handled = False
    Else
        e.Handled = True
    End If
End Sub