如何启动并等待外部进程？

Question

我正在尝试启动一个外部进程并等待它处于活动状态，然后再继续执行我的程序。我正在根据进程名称进行搜索，但如果进程名称不是我所期望的，我的实现就会出现问题。

//When Method1 is called, it will load the data and bring a pop up
//as adobe save dialog box (as a save dialog exe in the task bar)
Method1(); 

while (true)
{
    foreach (Process clsProcess in Process.GetProcesses())
    {
        if (clsProcess.ProcessName.Contains("AdobeARM"))
        {
            isOpened = true;
        }
    }  

    //Once the pop up from Method 1 comes i call other methods     
    if (isOpened)
    {
        Method2();
        Method3();
        Method4();
        break;
    }
}

如果永远找不到进程，这可能会导致无限循环！处理此问题或替代while 循环的最佳方法是什么？

Answer 1

摆脱这段时间。

它将执行检查，然后如果存在 Adob​​eARM 进程，它将运行您的方法，否则将跳过它们。将 Method1 之后的所有内容放在一个单独的函数中，然后从 System.Threading.Timer 调用该函数。

请注意，根据它在您的应用程序中的使用方式，您可能需要为线程问题添加额外的处理。

private Timer myTimer;

private void DoSomething()
{
    if (myTimer != null)
    {
        myTimer.Dispose();
        myTimer = null;
    }

    Method1();

    myTimer = new Timer(CheckForProcess, null, 100, 100);
}

private void CheckForProcess(object state)
{
    bool isOpened = false;
    foreach (Process clsProcess in Process.GetProcesses())
    {
        if (clsProcess.ProcessName.Contains("AdobeARM"))
        {
            isOpened = true;
            break;
        }
    }

    //Once the pop up from Method 1 comes i call other methods     
    if (isOpened)
    {
        myTimer.Dispose();
        myTimer = null;
        Method2();
        Method3();
        Method4();
    }
}

Answer 2

你说'我正在尝试启动一个外部进程并等待它在继续之前处于活动状态'，所以我想你使用：

Process prc = new Process(...);
prc.Start();

如果是，我会打电话给

prc.WaitForInputIdle();

然后继续。
来自 MSDN

WaitForInputIdle - Causes the Process component to wait indefinitely for the associated process to enter an idle state. This overload applies only to processes with a user interface and, therefore, a message loop.

Answer 3

可能只是休息？

while (true)
{


           foreach (Process clsProcess in Process.GetProcesses())
           {
                    if (clsProcess.ProcessName.Contains("AdobeARM"))
                    {
                          isOpened = true;
                    }
           }  
           //Once the pop up from Method 1 comes i call other methods                                  
           if (isOpened)
           {
             Method2();
             Method3();
             Method4();
             break;
           }
           else
             break; //BREAK HERE, CAUSE NO PROCESSES of ADOBE...
}

如果你想一次又一次地想出这个代码，使用Timer，但在这种情况下，显然不要使用更多的while循环。

Answer 4

使用睡眠总是有帮助的

System.Threading.Thread.Sleep(100); //100ms pause before continuing

如果你已经循环了超过 500 次（50 秒有延迟）你不会找到它并且应该跳出循环，那么有一个计数器或其他东西也可能是有意义的.

暂停将允许您的屏幕也重新绘制，而不是完全锁定线程。

Answer 5

尝试一个基于某个超时值结束的while循环，而不是while(true)：

//When Method1 is called, it will load the data and bring a pop up
//as adobe save dialog box (as a save dialog exe in the task bar)
Method1(); 

//define a "timeout" time one minute from now. (or whatever)
var timeout = DateTime.Now.AddSeconds(60);

//loop only while the current time has not exceeded the timeout
while (DateTime.Now < timeout)
{
    foreach (Process clsProcess in Process.GetProcesses())
    {
        if (clsProcess.ProcessName.Contains("AdobeARM"))
        {
            isOpened = true;
        }
    }  

    //Once the pop up from Method 1 comes i call other methods     
    if (isOpened)
    {
        Method2();
        Method3();
        Method4();
        break;
    }
    else
        Thread.Yield(); //gives other threads CPU time; Thread.Sleep() works too.
}

//If we exit the loop without isOpened being set, we should probably tell someone.
if(!isOpened) throw new Exception("The operation timed out waiting for AdobeARM.");