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如何检查窗体是否有焦点?

winforms vb.net

Thomas Carlton · 技术社区 · 7 年前

我有两个 WinForm MainForm 和 ChildForm .

我想说的是 主窗体 子型 应始终可见,并且 主窗体 失去焦点 子型 子型

这是我的密码:

AddHandler Me.MainForm.Activated, Sub()        
                                      Me.ChildForm.Show()                                              
                                  End Sub

AddHandler Me.MainForm.Deactivate, Sub()                                               
                                       If Not Me.ChildForm.Focused Then                                                   
                                           Me.ChildForm.Hide()
                                       End If
                                   End Sub

AddHandler Me.ChildForm.Deactivate, Sub()
                                        If Not MainForm.Focused Then
                                            Me.ChildForm.Hide()
                                        End If
                                    End Sub

有谁知道如何做到这一点吗?

1 回复 | 直到 7 年前

Han 7 年前

不确定这是否是一个好的方法,但是这个想法是使用MainForm和ChildForm活动状态的标志。这些标志是在触发MainForm和ChildForm的Activated和Deactive事件时设置的。为了简单起见,我将使用一个模块来存储标志和ChildForm的实例。然后在MainForm、Form1和Form2 Activated事件中调用SetChildVisible()方法。将启动对象设置为MainForm。

模块1

Module Module1

    Public FChild As ChildForm

    Public FMainActive As Boolean
    Public FChildActive As Boolean

    Public Sub SetChildVisible()
        FChild.Visible = Not FChildActive And FMainActive
    End Sub

End Module

Public Class MainForm

    Private Sub MainForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim f1 = New Form1
        Dim f2 = New Form2
        Dim child = New ChildForm

        Module1.FChild = child

        child.Show()
        f1.Show()
        f2.Show()
    End Sub

    Private Sub MainForm_Activated(sender As Object, e As EventArgs) Handles MyBase.Activated
        Module1.FMainActive = True
        Module1.SetChildVisible()
    End Sub

    Private Sub MainForm_Deactivate(sender As Object, e As EventArgs) Handles MyBase.Deactivate
        Module1.FMainActive = False
    End Sub

End Class

Public Class ChildForm

    Private Sub ChildForm_Activated(sender As Object, e As EventArgs) Handles MyBase.Activated
        Module1.FChildActive = True
    End Sub

    Private Sub ChildForm_Deactivate(sender As Object, e As EventArgs) Handles MyBase.Deactivate
        Module1.FChildActive = False
    End Sub

End Class

表格1

Public Class Form1

    Private Sub Form1_Activated(sender As Object, e As EventArgs) Handles MyBase.Activated
        Module1.SetChildVisible()
    End Sub

End Class

表格2

Public Class Form2

    Private Sub Form2_Activated(sender As Object, e As EventArgs) Handles MyBase.Activated
        Module1.SetChildVisible()
    End Sub

End Class