循环访问多面板创建标签异常：仅单个面板生效问题求助

问题根源 #

一个控件实例只能隶属于一个父容器。你当前的代码在循环中只创建了一个Label对象，随后尝试将它依次添加到多个Panel中。每次执行Controls.Add(lbl)时，这个Label会被自动从之前的父容器中移除，最终只会保留在最后一个执行添加操作的Panel里，这就是为什么只有一个面板能显示标签的原因。

解决方案 #

为每个Panel创建独立的Label实例，确保每个面板都拥有专属的控件对象。以下是两种实现方式：

方式一：逐个创建Label（直观写法）

Dim i As Integer = 0

For i = 0 To 7
    ' 为req1创建并添加Label
    Dim lbl1 As New Label() With {
        .Text = "Suppliant Name:",
        .Location = New Point(117, 10 * (i + 1)), ' 用i调整位置，避免标签重叠
        .Height = 15,
        .Width = 95
    }
    req1.Controls.Add(lbl1)
    
    ' 为req2创建并添加Label
    Dim lbl2 As New Label() With {
        .Text = "Suppliant Name:",
        .Location = New Point(117, 10 * (i + 1)),
        .Height = 15,
        .Width = 95
    }
    req2.Controls.Add(lbl2)
    
    ' 为其余面板重复上述逻辑
    Dim lbl3 As New Label() With {.Text = "Suppliant Name:", .Location = New Point(117, 10 * (i + 1)), .Height = 15, .Width = 95}
    req3.Controls.Add(lbl3)
    
    Dim lbl4 As New Label() With {.Text = "Suppliant Name:", .Location = New Point(117, 10 * (i + 1)), .Height = 15, .Width = 95}
    req4.Controls.Add(lbl4)
    
    Dim lbl5 As New Label() With {.Text = "Suppliant Name:", .Location = New Point(117, 10 * (i + 1)), .Height = 15, .Width = 95}
    req5.Controls.Add(lbl5)
    
    Dim lbl6 As New Label() With {.Text = "Suppliant Name:", .Location = New Point(117, 10 * (i + 1)), .Height = 15, .Width = 95}
    req6.Controls.Add(lbl6)
    
    Dim lbl7 As New Label() With {.Text = "Suppliant Name:", .Location = New Point(117, 10 * (i + 1)), .Height = 15, .Width = 95}
    req7.Controls.Add(lbl7)
Next

方式二：用数组批量处理（简洁写法）

将所有Panel存入数组，通过嵌套循环批量创建并添加Label，减少重复代码：

' 把需要添加Label的面板存入数组
Dim panels() As Panel = {req1, req2, req3, req4, req5, req6, req7}

Dim i As Integer = 0
For i = 0 To 7
    For Each panel In panels
        Dim lbl As New Label() With {
            .Text = "Suppliant Name:",
            .Location = New Point(117, 10 * (i + 1)),
            .Height = 15,
            .Width = 95
        }
        panel.Controls.Add(lbl)
    Next
Next

内容的提问来源于stack exchange，提问作者Heathani Bean