我正在使用C#和NUnit框架同时在单独的线程中执行多个测试。我想记录某些操作之间的时间,并为此创建了一个ActionTimeHelper类。
下面是类的代码以及使用类中方法的上下文
当我在并行机器人中运行两个测试时,调用Login方法然后只有一个测试完成,另一个测试抛出错误
(Message: System.NullReferenceException : Object reference not set to an instance of an object.
) at actionList.Add(new ActionTimeInfo()
我已将actionList设为ThreadStatic,以便在其自己的线程上运行的每个测试都有自己的副本,因此我无法弄清楚为什么会出现错误。
注意:如果我一次运行一个测试,一切正常
有人可以指导我这个。谢谢您的帮助。
已阅读一些文章Referencing a non static member with an instantiated object,Referencing an instantiated object in a static class (c#)但无法将我的具体问题联系起来
public static class ActionTimeHelper
{
private static readonly string _actionTimeLogFileName = "ActionTimeLog_" + string.Format("{0:yyyy_MM_dd_hhmmss}", DateTime.Now);
[ThreadStatic] private static FileStream _fileStream = null;
[ThreadStatic] private static StreamWriter _actionStreamWriter = null;
[ThreadStatic] private static JsonWriter _jsonWriter = null;
[ThreadStatic] private static List<ActionTimeInfo> actionList = new List<ActionTimeInfo>();
public static void CreateActionTimeLogFile(string logPath, string testName)
{
string dir = logPath + testName + @"\";
if (!Directory.Exists(dir))
{
Directory.CreateDirectory(dir);
}
_fileStream = File.Open(dir + _actionTimeLogFileName + ".json", FileMode.CreateNew);
_actionStreamWriter = new StreamWriter(_fileStream);
_jsonWriter = new JsonTextWriter(_actionStreamWriter);
_jsonWriter.Formatting = Formatting.Indented;
JsonSerializer serializer = new JsonSerializer();
serializer.Serialize(_jsonWriter, actionList);
_fileStream.Flush();
_actionStreamWriter.Flush();
_jsonWriter.Flush();
}
public static void StartActionTime(string actionName)
{
actionList.Add(new ActionTimeInfo()
{
TestName = TestContext.CurrentContext.Test.Name,
ActionName = actionName,
StartTime = DateTime.Now
});
}
public static void EndActionTime(string actionName)
{
ActionTimeInfo endAction = actionList.Find(actionInfo => actionInfo.ActionName.Equals(actionName));
endAction.EndTime = DateTime.Now;
endAction.ExecutionTime = endAction.EndTime.Subtract(endAction.StartTime);
}
}
public class ActionTimeInfo
{
public string TestName { get; set; }
public string ActionName { get; set; }
public DateTime StartTime { get; set; }
public DateTime EndTime { get; set; }
public TimeSpan ExecutionTime { get; set; }
}
public void Login(string username, string password)
{
ActionTimeHelper.StartActionTime("Navigating to URL");
ActionTimeHelper.EndActionTime("Navigating to URL");
ActionTimeHelper.StartActionTime("Login Action");
ActionTimeHelper.EndActionTime("Login Action");
Thread.Sleep(30000);
}
[TearDown]
public void TestTearDown()
{
ActionTimeHelper.CreateActionTimeLogFile(LogPath, TestContext.CurrentContext.Test.Name);
}
实际结果:空引用错误预期结果:无空引用错误
“不要为标记有ThreadStaticAttribute的字段指定初始值,因为这样的初始化只在类构造函数执行时发生一次,因此只影响一个线程。如果未指定初始值,则可以依赖于将字段初始化为其默认值(如果它是值类型),如果它是引用类型则为null。
从
https://docs.microsoft.com/en-us/dotnet/api/system.threadstaticattribute?view=netframework-4.8