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ASP.Net实体框架(ASP.Net Entity Framework)

 我只是尝试使用ASP.Net实体框架，这是我第一次尝试使用ORM框架，因此忍受着我如果我吠叫错误的树。  
 为了简化这个问题，我得到了以下两张表格  
 日历  
 CalendarID用户标识日期事件名称  
 用户  
 UserId用户名  
 我已经将它们添加到我的实体框架模型中，并建立了表之间的链接。 然后，我可以通过使用类似的东西来显示我的MVC视图中的日历列表  
 
 <％= calendarEntry.DateAdded％>  
 
 但是，如果我然后尝试使用  
 
 > <％= calendarEntry.Users.Username％>：<％= calendarEntry.DataAdded％> 
 它调用了calendarEntry.Users，因为它说它是空的。 为什么实体框架不通过使用细节？ 我需要在模型设计器中更改某些内容吗？ 
 如果它有助于将数据发送到视图的MVC控制器中的代码就像这样 
 var Entities = new UnityGamersEntities（）; 返回查看（Entities.Calendar）; 
 真的希望这是有道理的。 

I'm just trying the ASP.Net Entity framework its the first time I've tried to use an ORM framework so bear with me If I'm barking up the wrong tree. 
To simplify the problem I've got the following 2 tables 
Calendar 
CalendarID UserID Date EventName 
Users 
UserId Username 
I've added them both to my Entity Framework model and its established the link between the tables. I'm able to then display a list of Calendars from my MVC view, by using something like 
 
<%= calendarEntry.DateAdded%> 
 
However if I then try to use 
 
><%= calendarEntry.Users.Username%> : <%= calendarEntry.DataAdded%>
 It falls over on the call to calendarEntry.Users as it says it is null. Why is the entity framework not pulling through the use details? Do I need to change something in my model designer? 
 If it helps the code in the MVC controller that sends the data to the view is like this
 var Entities = new UnityGamersEntities(); return View(Entities.Calendar);
 Really hope that makes sense.
 

原文：https://stackoverflow.com/questions/551549

更新时间：2022-08-20 20:08

最满意答案

 正如@ThiefMaster所提到的，您可以使用子进程模块 ，它提供poll （检查进程是否终止）和communicate方法（将数据发送到子进程stdin）。  
 这些方面的东西：  
# Starts encoding in a subprocess
proc = subprocess.Popen(['ffmpeg', '-i' 'myinput', 'myoutput'])

duration = 3
sleeptime = 0
while proc.poll() is None and sleeptime < 3: 
    # Wait for the specific duration or for the process to finish
    sleep(1)
    sleeptime += 1

# If process is not terminated
if proc.poll() is None:
    # Cancels process, waits for it to complete
    proc.communicate("q")
 
 如果尚未在指定的duration内完成，则将取消子进程。 

As @ThiefMaster mentioned, you can use the subprocess module, which provides both poll (to check whether the process is terminated) and a communicate method (to send data to the subprocess stdin). 
Something along these lines: 
# Starts encoding in a subprocess
proc = subprocess.Popen(['ffmpeg', '-i' 'myinput', 'myoutput'])

duration = 3
sleeptime = 0
while proc.poll() is None and sleeptime < 3: 
    # Wait for the specific duration or for the process to finish
    sleep(1)
    sleeptime += 1

# If process is not terminated
if proc.poll() is None:
    # Cancels process, waits for it to complete
    proc.communicate("q")
 
Will cancel the subprocess if it has not finished within the specified duration.

ASP.Net实体框架(ASP.Net Entity Framework)

日历

用户

Calendar

Users

最满意答案

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