我怎么知道进程是否正在运行？

Question

当我获得对a的引用时System.Diagnostics.Process,如何知道进程当前是否正在运行？

Answer 1

这是一种使用名称的方法:

Process[] pname = Process.GetProcessesByName("notepad");
if (pname.Length == 0)
  MessageBox.Show("nothing");
else
  MessageBox.Show("run");

您可以循环所有进程以获取ID以供以后操作:

Process[] processlist = Process.GetProcesses();
foreach(Process theprocess in processlist){
   Console.WriteLine("Process: {0} ID: {1}", theprocess.ProcessName, theprocess.Id);
}

Answer 2

这是我在使用反射器后找到的最简单的方法.我为此创建了一个扩展方法:

public static class ProcessExtensions
{
    public static bool IsRunning(this Process process)
    {
        if (process == null) 
            throw new ArgumentNullException("process");

        try
        {
            Process.GetProcessById(process.Id);
        }
        catch (ArgumentException)
        {
            return false;
        }
        return true;
    }
}

该Process.GetProcessById(processId)方法调用该ProcessManager.IsProcessRunning(processId)方法并抛出ArgumentException该进程不存在的情况.由于某种原因,ProcessManager班级是内部的......

Answer 3

同步解决方案:

void DisplayProcessStatus(Process process)
{
    process.Refresh();  // Important


    if(process.HasExited)
    {
        Console.WriteLine("Exited.");
    }
    else
    {
        Console.WriteLine("Running.");
    } 
}

异步解决方案:

void RegisterProcessExit(Process process)
{
    // NOTE there will be a race condition with the caller here
    //   how to fix it is left as an exercise
    process.Exited += process_Exited;
}

static void process_Exited(object sender, EventArgs e)
{
   Console.WriteLine("Process has exited.");
}

Answer 4

reshefm有一个非常好的答案; 但是,它没有考虑到从未开始过程的情况.

这是他发布的修改版本.

    public static bool IsRunning(this Process process)
    {
        try  {Process.GetProcessById(process.Id);}
        catch (InvalidOperationException) { return false; }
        catch (ArgumentException){return false;}
        return true;
    }

我删除了他的ArgumentNullException,因为它实际上假设是一个空引用异常,它仍然被系统抛出,我还考虑了从未开始进程或使用close()方法关闭的情况.处理.

Answer 5

这应该是一个单行:

public static class ProcessHelpers {
    public static bool IsRunning (string name) => Process.GetProcessesByName(name).Length > 0;
}