C# 16 Reworks unsafe Into a Caller Contract
C# 16 redesigns the unsafe keyword so it propagates a caller obligation instead of silently opening an unsafe context, with inner unsafe blocks now mandatory.
Tag: csharp
300 posts · Page 16 of 30
ConfigureAwait(false) vs default in .NET 11: does it still matter?
ConfigureAwait(false) is still mandatory in library code that may run under a SynchronizationContext (WinForms, WPF, MAUI). In application code on ASP.NET Core, a console app, or a worker service running on .NET 11, it is a no-op.
IEnumerable vs IAsyncEnumerable vs IQueryable in C#: which one should the method return?
Three sequence interfaces, three execution models. Use IQueryable when a database can translate the query, IAsyncEnumerable when the producer is async and you want to stream, IEnumerable for everything else in memory.
async void vs async Task in C#: when each is correct
async Task is the default and async void is the exception. Use async void only for event handlers, top-level message-loop handlers, and a handful of framework callbacks that demand a void signature. Everywhere else, async Task wins on exceptions, composition, and testability.
record vs class vs struct in C#: a decision matrix
C# 14 gives you four data-type shapes -- class, record class, struct, and record struct. This is the decision matrix: when each one is correct, what each one costs, and the rules that pick for you.
Fix: C# 14 overload resolution breaking change with Span and ReadOnlySpan
After upgrading to C# 14 / .NET 10, calls like array.Contains, x.Reverse(), and MemoryMarshal.Cast suddenly bind to different overloads or stop compiling. Here is what changed and how to pin the old behaviour where it matters.
Fix: framework_version=6.0.0 was not found when launching a .NET 6 binary
The .NET 6 runtime is gone or mismatched. Either install net6.0 again, roll forward to net8.0 via runtimeconfig, retarget the csproj, or ship self-contained.
dotnet new mcpserver Now Ships in the .NET 11 Preview 4 SDK
.NET 11 Preview 4 bundles the mcpserver project template directly into the SDK. No separate Microsoft.McpServer.ProjectTemplates install, no preview feed dance. Pick stdio or HTTP transport, opt into Native AOT, and dotnet new mcpserver -o MyServer is the whole setup.
.NET 11 Adds Deadlock-Free Process Output Capture
.NET 11 Preview 4 ships new System.Diagnostics.Process APIs that drain stdout and stderr concurrently, plus one-line run-and-capture helpers and KillOnParentExit.
Fix: A possible object cycle was detected
System.Text.Json refuses to serialize graphs with back-references. Set ReferenceHandler.IgnoreCycles, project to a DTO, or mark the back-pointer with [JsonIgnore]. Preserve is a last resort.