声明新窗体变量类型VB.NET

Question

我想显示多个窗体相等，首先声明一个Form类型的变量，然后设置该变量的名称，然后显示它，但我不能有成功。

它不显示任何新窗口。

Dim from_var As New Form 
from_var = inventory_stat_item 

With from_var 
    .MdiParent = main 
    .StartPosition = FormStartPosition.CenterScreen 
    .Show() 
End With 

UPDATE： 变量应具有以下形式的名称：（inventory_stat_item | inventory_edit_item | inventory_new_item）

Answer 1

你应该能够做你想做的只要您事先创建并更新Forms即可。像这个快速和肮脏的例子。

Public Class Form1 
    Dim inventory_stat_item As Form2 = New Form2 
    Dim inventory_edit_item As Form3 = New Form3 
    Dim inventory_new_item As Form4 = New Form4 
    Public Sub New() 

     ' This call is required by the designer. 
     InitializeComponent() 

     ' Add any initialization after the InitializeComponent() call. 

     showForms(inventory_edit_item) 
     showForms(inventory_new_item) 
     showForms(inventory_stat_item) 

    End Sub 

    Private Sub showForms(from_var As Form) 
     With from_var 
      .MdiParent = Me 
      .StartPosition = FormStartPosition.CenterScreen 
      .Show() 

     End With 
    End Sub 
End Class 

Answer 2

你不能做到这一点。每一个你叫New inventory_stat_item他们创建了新的对象引用。

必须拆分代码

调用一次（例如：当窗体加载），当用户点击的东西

With from_var 
    .MdiParent = Me 
    .StartPosition = FormStartPosition.CenterScreen 
    .Show() 
End With 

Dim from_var As New inventory_stat_item 

叫