Dim txtHeight As Integer = 16 Dim txtWidth As Integer = 100 Dim txtA(txtNum - 1) As TextBox Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim er As String = "" For i = 0 To txtNum - 1 If txtA(i).Text = "" Then er = er & i + 1 & "." End If If er <> "" Then MsgBox("第" & er & "項目沒填資料") End If End Sub Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Dim i As Integer For i = 0 To txtNum - 1 txtA(i) = New TextBox txtA(i).Text = "" Me.Controls.Add(txtA(i)) txtA(i).Width = txtWidth txtA(i).Font = New Font("新細明體", 16) txtA(i).Left = 100 txtA(i).Top = (txtA(i).Height + 8) * i End Sub End Class 小改了一下你的程式
參考看看吧

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        '畫面上 Button1 ,TextBox1.Text="",TextBox2.Text=2,TextBox3.Text=""
        '結果 TextBox1 ,TextBox3 會彈出訊息 
        For Each ctl As Control In Me.Controls
            If (TypeOf ctl Is TextBox) Then
                Dim Txt As TextBox = DirectCast(ctl, TextBox)
                If Txt.Text = "" Then
                    MsgBox(Txt.Name & "欄位必須填資料")
                    'Exit Sub
                End If
            End If
        Next ctl
    End Sub