如何在更新數據庫時用空值填充空文本框？

Question

我有一個包含6個groupboxes和120個文本框的表單。在數據更新到數據庫期間，我希望空白文本框返回值「-NA-」。我嘗試了下面的代碼，但我不斷收到錯誤：

 For i As Integer = 1 To 20 
     If GroupBox1.Controls("CollarTB" & i).Text = String.Empty Then 
      GroupBox1.Controls("CollarTB" & i).Text = "-NA-" 
     End If 

     If Me.GroupBox1.Controls("CollarTB" & i).Text = String.Empty Then 
      Me.Controls("CollarTB" & i).Text = "-NA-" 
     End If 

     If Form9.Controls(i).Text = String.Empty Then 
      Form9.Controls(i).Text = "-NA-" 
     End If 

    Next 



     If FrntTB1.Text = String.Empty Then FrntTB1.Text = "-NA-" 

這怎麼辦？任何解決方案？

另外，我還有一個包含180個文本框的groupbox。我想一次從一行數據庫中填充它們。可能嗎？如果是這樣，怎麼樣？

Answer 1

您可以使用linq過濾從form的groupboxes並在groupboxes你可以過濾掉textboxes，然後簡單地設置的值到textboxes按您的要求。試試這個代碼，

LINQ的I型：

For Each xGroupBox As GroupBox In Me.Controls.OfType(Of GroupBox)() 

    For Each xTextBox As TextBox In xGroupBox.Controls.OfType(Of TextBox)() 

     If xTextBox.Name.StartsWith("CollarTB") andalso xTextBox.text = string.empty Then 
      xTextBox.Text = "-NA-" 
     End If 

    Next 

Next 

LINQ的II型：

For Each xGroupBox As GroupBox In Me.Controls.OfType(Of GroupBox)() 
    For Each xTextBox As TextBox In From xTxtbx In xGroupBox.Controls.OfType(Of TextBox)() Where xTxtbx.Text.StartsWith("CollarTB") and xTxtbx.text = string.empty 
     xTextBox.Text = "-NA-" 
    Next 
Next 

非LINQ的版本：

For Each xControls As Control In Me.Controls 

    If TypeOf xControls Is GroupBox Then 

     For Each xControls1 As Control In xControls.Controls 

      If TypeOf xControls1 Is TextBox Then 

       If xControls1.Name.StartsWith("CollarTB") andalso xControls1.text = string.empty Then 

        xControls1.Text = "-NA-" 

       End If 

      End If 

     Next 

    End If 
    Next