如何在更新数据库时用空值填充空文本框？

Question

我有一个包含6个groupboxes和120个文本框的表单。在数据更新到数据库期间，我希望空白文本框返回值“-NA-”。我尝试了下面的代码，但我不断收到错误：

 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-" 

这怎么办？任何解决方案？

另外，我还有一个包含180个文本框的groupbox。我想一次从一行数据库中填充它们。可能吗？如果是这样，怎么样？

Answer 1

您可以使用linq过滤从form的groupboxes并在groupboxes你可以过滤掉textboxes，然后简单地设置的值到textboxes按您的要求。试试这个代码，

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