文本框数据合法性检验

谢谢您的解答！
试了下，这段语句只能判断文本框（TextBox1）是否输入了数字，不能判断窗体内其他文本框（比如TextBox2、TextBox3……是否输入了数字）。从其他网站上搜到下列子过程，可以解决这个问题，供大家参考。
Public Class form1
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Call IsExists(Me)
End Sub

    Public Sub IsExists(ByVal frmTestText As Windows.Forms.Form)
        Dim c As Control
        For Each c In frmTestText.Controls
            If TypeOf c Is TextBox Then
                c.Text = c.Text.Trim
                If c.Text = "" Or Not IsNumeric(c.Text) Then
                    c.Text = ""
                    MsgBox("输入数据有误，请重新输入 !")
                    c.Focus()
                    Exit Sub
                End If
            End If
        Next
    End Sub
End Class