如何清除 GroupBox 中的每个 TextBox

Question

我在清空 GroupBox 中的每个文本框时遇到问题，因为我的循环仅在 textbox1 具有值时清除所有文本框，但如果我尝试绕过 textbox1 并跳转到输入数据到 textbox2，我的ClearCtrlText方法不行。

如果需要更改，请查看我的循环代码：

Public Sub ClearCtrlText(ByVal root As Control)

    For Each ctrl As Control In root.Controls
        If TypeOf ctrl Is TextBox Then ' textbox set to empty string
            If ctrl.Text <> "" Then
                ctrl.Text = Nothing
            End If
        End If
    Next
End Sub

Answer 1

您需要像这样 RECURSE 到容器中：

Public Class Form1

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        ClearCtrlText(Me)
    End Sub

    Public Sub ClearCtrlText(ByVal root As Control)
        For Each ctrl As Control In root.Controls
            If TypeOf ctrl Is TextBox Then ' textbox set to empty string
                If ctrl.Text <> "" Then
                    ctrl.Text = Nothing
                End If
            ElseIf ctrl.HasChildren Then
                ClearCtrlText(ctrl)
            End If
        Next
    End Sub

End Class

Answer 2

我很想把它写成扩展方法：

Imports System.Runtime.CompilerServices

Public Module ControlExtensions

    <Extension>
    Public Sub ClearTextBoxes(source As Control)
        For Each child As Control In source.Controls
            Dim tb = TryCast(child, TextBox)

            If tb Is Nothing Then
                child.ClearTextBoxes()
            Else
                tb.Clear()
            End If
        Next
    End Sub

End Module

然后您可以在控件上调用它，就好像它是一个成员一样，例如

GroupBox1.ClearTextBoxes()

此方法还包括访问子容器内的子控件所需的递归，例如GroupBox.

里面的 Panel

如何清除 GroupBox 中的每个 TextBox

How to clear every TextBox inside a GroupBox

vb.net

textbox

winforms