vb 当其他应用全屏时自动隐藏窗体

您可以使用Windows API来检测其他应用程序是否全屏，并相应地隐藏您的窗体。以下是一个VB.NET示例：

首先，请确保在代码文件的顶部添加以下命名空间：

Imports System.Runtime.InteropServices

然后，您需要声明以下两个Windows API函数：

Private Declare Function GetForegroundWindow Lib "user32" () As IntPtr
Private Declare Function GetWindowPlacement Lib "user32" (ByVal hWnd As IntPtr, ByRef lpwndpl As WINDOWPLACEMENT) As Boolean

<Serializable, StructLayout(LayoutKind.Sequential)>
Public Structure WINDOWPLACEMENT
    Public Length As UInteger
    Public flags As UInteger
    Public ShowCmd As UInteger
    Public ptMinPosition As POINTAPI
    Public ptMaxPosition As POINTAPI
    Public rcNormalPosition As RECT
End Structure

<Serializable, StructLayout(LayoutKind.Sequential)>
Public Structure RECT
    Public Left As Integer
    Public Top As Integer
    Public Right As Integer
    Public Bottom As Integer
End Structure

<Serializable, StructLayout(LayoutKind.Sequential)>
Public Structure POINTAPI
    Public x As Integer
    Public y As Integer
End Structure

接下来，在窗体加载时，您可以使用以下代码来轮询其他应用程序是否全屏，并相应地隐藏您的窗体：

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Timer1.Interval = 100 ' 每100毫秒检查一次
    Timer1.Enabled = True
End Sub

Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
    Dim hWnd As IntPtr = GetForegroundWindow()
    Dim wp As WINDOWPLACEMENT = Nothing
    wp.Length = CUInt(Marshal.SizeOf(wp))
    GetWindowPlacement(hWnd, wp)
    If wp.ShowCmd = 3 Then ' 如果前台窗口是全屏状态
        Me.Hide() ' 隐藏本窗口
    Else
        Me.Show() ' 显示本窗口
    End If
End Sub

这将启动一个计时器，每100毫秒检查一次前台窗口是否全屏。如果是，您的窗体将被隐藏。否则，您的窗体将被显示。请注意，此方法可能会影响您的应用程序的性能，因为它需要在后台运行，并且需要定期轮询其他应用程序。如果您的应用程序需要更高的性能，请考虑其他方法，例如使用Windows消息循环来检测全屏状态。