持续监控进程是否正在运行

Question

我有以下代码：

Dim p() As Process

Private Sub CheckIfRunning()
    p = Process.GetProcessesByName("skype") 'Process name without the .exe
    If p.Count > 0 Then
        ' Process is running
        MessageBox.Show("Yes, Skype is running")
    Else
        ' Process is not running
        MessageBox.Show("No, Skype isn't running")
    End If
End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    CheckIfRunning()
End Sub

而且效果很好！

但我想知道如何将其转换为监控应用程序，以不断检查进程是否正在运行。是否像每 1 秒检查一次计时器一样简单，还是有更好、更有效的方法来解决这个问题。

最后，我想要一个标签，根据流程显示“正在运行”或“未运行”，但我需要一些东西来不断地观察流程。

Answer 1

如果您需要应用程序一直运行，那么您根本不需要 Timer。订阅Process.Exited()事件以在它关闭时收到通知。例如，使用记事本：

Public Class Form1

    Private P As Process
    Private FileName As String = "C:\Windows\Notepad.exe"

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim ps() As Process = Process.GetProcessesByName(Path.GetFileNameWithoutExtension(FileName))
        If ps.Length = 0 Then
            P = Process.Start(FileName)
            P.EnableRaisingEvents = True
            AddHandler P.Exited, AddressOf P_Exited
        Else
            P = ps(0)
            P.EnableRaisingEvents = True
            AddHandler P.Exited, AddressOf P_Exited
        End If
    End Sub

    Private Sub P_Exited(sender As Object, e As EventArgs)
        Console.WriteLine("App Exited @ " & DateTime.Now)
        Console.WriteLine("Restarting app: " & FileName)
        P = Process.Start(FileName)
        P.EnableRaisingEvents = True
        AddHandler P.Exited, AddressOf P_Exited
    End Sub

End Class

这将使其始终保持打开状态，假设您想在它尚未运行时打开它。

如果您不想自己打开它，并且需要检测它何时打开，那么您可以通过ManagementEventWatcher使用 WMI，如上一个 SO question 中所述。