以第二种形式放置多个标签

Question

大家好，我想问一下，这是否是一个很好的代码，可以使用一个按钮将多个标签放在第二个表单中，并使用第一个表单中的文本？在此先感谢大家，祝大家编码愉快。

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click

Dim lbl As Label = New Label     'Create your Label
    'change the location..    
    lbl.Location = New Point(50, 50) 'Set Label Location
    lbl.Text = TextBox1.Text         'Set Label Text
    lbl.ForeColor = Color.Black       'Set Label ForeColor
    frm2.Controls.Add(lbl)           'Add Label to it

    Return

    'change the location..    
    lbl.Location = New Point(10, 20) 'Set Label Location
    lbl.Text = TextBox1.Text         'Set Label Text
    lbl.ForeColor = Color.Black       'Set Label ForeColor
    frm2.Controls.Add(lbl)           'Add Label to it

    Return

End Sub

它只显示第一个标签，但不显示我将输入的下一个标签...

form2 代码

Public Class Form2
Public lbl As New Label
Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    Me.Controls.Add(lbl)

End Sub

结束类

问题解决了..非常感谢 Sir Plutonix 和 Steve 的帮助，我真的很感激 :) 我接受了 Plutonix 的建议，使用多个文本框而不是一个文本框，我在开始我的项目时使用了 Steve 的示例代码。 . 再次感谢:)

Answer 1

您需要声明一个全局类级别变量来保持对您的 Form2 的引用，然后当您单击按钮并且全局类级别变量什么都不是（第一次创建）时，您创建 Form2 实例，添加标签和大多数重要添加一个事件处理程序，将在关闭 frm2 实例时调用该事件处理程序。然后显示表格并将其放在最前面。
如果您的用户重新单击该按钮，则不会创建新表单（此时 frm2 不是什么），相反，如果您的用户关闭 frm2，则将调用事件处理程序并将内部类级别变量重置为无。现在，如果您的用户再次单击该按钮，frm2 将被重新创建

Private frm2 As Form2

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click

    if frm2 Is Nothing then
       frm2 = new Form2
       AddHandler frm2.FormClosed, AddressOf Me.Form2HasBeenClosed

       Dim lbl As Label = New Label     
       lbl.Location = New Point(50, 50) 
       lbl.Text = "FirstLabelText"
       lbl.ForeColor = Color.Black     

       frm2.Controls.Add(lbl)          

       Dim lbl2 = New Label
       lbl2.Location = New Point(10, 20) 
       lbl2.Text = "TextForSecondLabel"
       lbl2.ForeColor = Color.Black      
       frm2.Controls.Add(lbl2)         
   End if

   frm2.Show()
   frm2.BringToFront
End Sub  

Sub Form2HasBeenClosed(sender As Object, e As FormClosedEventArgs)
   frm2 = Nothing
End Sub


Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
    if frm2 IsNot Nothing Then
        frm2.Show(Me)            'Show Second Form  
    End If      
End Sub

Answer 2

Private LabelCount As Integer = 0

Private Sub Button3_Click(yada yada yada

' I think this is actually fixing a nonexistant problem
' stemming from misunderstanding the issue
if frm2 Is Nothing then
   frm2 = new Form2
   AddHandler frm2.FormClosed, AddressOf Me.Form2HasBeenClosed

   Dim lbl As Label = New Label 
   lbl.Text = TextBox1.Text
   lbl.ForeColor = Color.Black 

   Select Case LabelCount
       Case 0
          lbl.Location = New Point(50, 50) 
       Case 1
          lbl.Location = New Point(10, 20) 

       Case Else
          ' not specified
          Exit Sub
   End Select
   LabelCount +=1                  ' dont forget this
   frm2.Controls.Add(lbl)

End if

 frm2.Show()
 frm2.BringToFront
 End Sub