Waiting for all threads to complete, with a timeout
I still think using Join is simpler. Record the expected completion time (as Now+timeout), then, in a loop, do if(!thread.Join(End-now)) throw new NotFinishedInTime();
c#
What’s so bad about building XML with string concatenation?
You can end up with invalid XML, but you will not find out until you parse it again – and then it is too late. I learned this the hard way.
ASP.NET Core v2 (2015) MVC : How to get raw JSON bound to a string without a type?
The cleanest option I’ve found is adding your own simple InputFormatter: public class RawJsonBodyInputFormatter : InputFormatter { public RawJsonBodyInputFormatter() { this.SupportedMediaTypes.Add(“application/json”); } public override async Task<InputFormatterResult> ReadRequestBodyAsync(InputFormatterContext context) { var request = context.HttpContext.Request; using (var reader = new StreamReader(request.Body)) { var content = await reader.ReadToEndAsync(); return await InputFormatterResult.SuccessAsync(content); } } protected override bool CanReadType(Type type) … Read more
How to consume a Scoped service from a Singleton?
A good way to use services inside of hosted services is to create a scope when needed. This allows to use services / db contexts etc. with the lifetime configuration they are set up with. Not creating a scope could in theory lead to creating singleton DbContexts and improper context reusing (EF Core 2.0 with … Read more
How can I get the name of a variable passed into a function?
What you want isn’t possible directly but you can use Expressions in C# 3.0: public void ExampleFunction(Expression<Func<string, string>> f) { Console.WriteLine((f.Body as MemberExpression).Member.Name); } ExampleFunction(x => WhatIsMyName); Note that this relies on unspecified behaviour and while it does work in Microsoft’s current C# and VB compilers, and in Mono’s C# compiler, there’s no guarantee that … Read more
Exceptions that can’t be caught by try-catch block in application code
Yes, there are some others: The ThreadAbortedException is special. It will always be re-raised when caught unless the catch block calls ResetAbort(). It is entirely uncatchable when the CLR performs a rude abort of the thread. Done when the AppDomain gets unloaded for example, typically at program exit. Any native exceptions thrown by unmanaged code … Read more
Passing a vector/array from unmanaged C++ to C#
As long as the managed code does not resize the vector, you can access the buffer and pass it as a pointer with vector.data() (for C++0x) or &vector[0]. This results in a zero-copy system. Example C++ API: #define EXPORT extern “C” __declspec(dllexport) typedef intptr_t ItemListHandle; EXPORT bool GenerateItems(ItemListHandle* hItems, double** itemsFound, int* itemCount) { auto … Read more
Can you prevent your ASP.NET application from shutting down?
You can do it a few ways. If you have control over IIS, you can change the “Idle Timeout” within the application pool, by default it is 20 minutes. If you do NOT have control over IIS (Shared or other hosting), you can use an external service to ping the site. MyWebKeepAlive or Pingdom are … Read more
Async ShowDialog
It’s easy to implement with Task.Yield, like below (WinForms, no exception handling for simplicity). It’s important to understand how the execution flow jumps over to a new nested message loop here (that of the modal dialog) and then goes back to the original message loop (that’s what await progressFormTask is for): namespace WinFormsApp { internal … Read more
How to clear browser cache on browser back button click in MVC4?
The problem with your approach is that you are setting it where it is already too late for MVC to apply it. The following three lines of your code should be put in the method that shows the view (consequently the page) that you do not want to show. Response.Cache.SetCacheability(HttpCacheability.NoCache); Response.Cache.SetExpires(DateTime.UtcNow.AddHours(-1)); Response.Cache.SetNoStore(); If you want … Read more