Question

我正在尝试检查javaw.exe是否具有焦点，然后执行某些代码。

以前我有代码可以查找javaw.exe的进程ID，然后将它与当前有焦点的进程进行比较，该进程工作了一段时间，但后来我注意到我运行了多个javaw.exe进程，它只适用于其中一个进程，而当任何javaw.exe进程具有焦点时我需要它才能工作。

有没有办法做到这一点？

Answer 1

您可以使用GetForegroundWindow()和GetWindowThreadProcessId() WinAPI函数轻松确定这一点。

首先调用GetForegroundWindow以获取当前焦点窗口的窗口句柄，然后调用GetWindowThreadProcessId以检索该窗口的进程ID。最后通过调用Process class

将其作为Process.GetProcessById()实例获取

Public NotInheritable Class ProcessHelper
    Private Sub New() 'Make no instances of this class.
    End Sub

    <DllImport("user32.dll", SetLastError:=True)> _
    Private Shared Function GetForegroundWindow() As IntPtr
    End Function

    <DllImport("user32.dll", SetLastError:=True)> _
    Private Shared Function GetWindowThreadProcessId(ByVal hWnd As IntPtr, ByRef lpdwProcessId As UInteger) As Integer
    End Function

    Public Shared Function GetActiveProcess() As Process
        Dim FocusedWindow As IntPtr = GetForegroundWindow()
        If FocusedWindow = IntPtr.Zero Then Return Nothing

        Dim FocusedWindowProcessId As UInteger = 0
        GetWindowThreadProcessId(FocusedWindow, FocusedWindowProcessId)

        If FocusedWindowProcessId = 0 Then Return Nothing
        Return Process.GetProcessById(CType(FocusedWindowProcessId, Integer))
    End Function
End Class

用法示例：

Dim ActiveProcess As Process = ProcessHelper.GetActiveProcess()

If ActiveProcess IsNot Nothing AndAlso _
    String.Equals(ActiveProcess.ProcessName, "javaw", StringComparison.OrdinalIgnoreCase) Then
    MessageBox.Show("A 'javaw.exe' process has focus!")
End If

希望这有帮助！

如何检查某个流程是否具有焦点？

1 个答案: