vb.net 如果已经打开，将 MDIChild 表单放在前面
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Bring MDIChild form to front if already open
提问by OMGSOMETAL
I've been struggling to get this to work...I have a button on a MDIchild form that opens another MDIchild form, but if the form is already open, it does not recognize it and opens a new one instead of bringing it to front. This is the code i've got:
我一直在努力让它工作......我在 MDIchild 表单上有一个按钮可以打开另一个 MDIchild 表单，但是如果表单已经打开，它无法识别它并打开一个新的而不是将它带到正面。这是我得到的代码：
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Dim MDIForm4 As New Form4
MDIForm4.MdiParent = Me
MDIForm4.Show()
End Sub
This works for the button to open the new form, and then I tried adding this:
这适用于打开新表单的按钮，然后我尝试添加：
If Not Form4 Is Nothing Then
Form4.BringToFront()
End If
But with no positive outcome. Does someone have any ideas?
但没有积极的结果。有人有什么想法吗？
Regards,
问候，
Jorge Brito
豪尔赫·布里托
回答by Steve
Here is how I typically do that:
这是我通常的做法：
For Each f As Form In Application.OpenForms
If TypeOf f Is frmTest Then
f.Activate()
Exit Sub
End If
Next
Dim myChild As New frmTest
myChild.MdiParent = Me
myChild.Show()
Notice this uses Application.OpenForms, you can use your Me.MdiChildren (assuming Me = this MDI form) if you want just the children of your main form.
请注意，这使用 Application.OpenForms，如果您只需要主窗体的子项，则可以使用 Me.MdiChildren（假设 Me = 这个 MDI 窗体）。
回答by OMGSOMETAL
Fixed now!
现在固定！
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
For Each f As Form In Application.OpenForms
If TypeOf f Is Form4 Then
f.Activate()
Exit Sub
End If
Next
Dim MDIForm As New Form4
MDIForm.MdiParent = Form2
MDIForm.Show()
End Sub
I was defining the MDI parent on the wrong form!
我在错误的形式上定义了 MDI 父级！
