👀 Views: 105 💬 Answers: 1 📅 Created: 2025-06-05

c# memory-mapped-file inter-process-communication C#

I'm experimenting with I'm experiencing an issue with `MemoryMappedFile` in C# where the data written by one process isn't being read correctly by another process... I am using .NET 5 and trying to share data between two console applications. The writer process successfully writes a string to the memory-mapped file, but the reader process keeps returning an empty string. In my writer code, I'm doing the following: ```csharp using System; using System.IO.MemoryMappedFiles; class Writer { static void Main() { using (MemoryMappedFile mmf = MemoryMappedFile.CreateNew("testmap", 10000)) { using (var stream = mmf.CreateViewStream()) { using (var writer = new StreamWriter(stream)) { writer.Write("Hello from Writer!"); } } } } } ``` In my reader code, I have: ```csharp using System; using System.IO.MemoryMappedFiles; class Reader { static void Main() { using (MemoryMappedFile mmf = MemoryMappedFile.OpenExisting("testmap")) { using (var stream = mmf.CreateViewStream()) { using (var reader = new StreamReader(stream)) { string message = reader.ReadToEnd(); Console.WriteLine(message); } } } } } ``` When I run the writer first and then the reader, the output from the reader is just an empty string. I checked that both processes are using the same name for the memory-mapped file, yet I'm not getting any data. I've considered that the stream might not be flushed properly in the writer, but adding `writer.Flush()` didn't change the behavior. Is there something specific that I might be missing regarding the lifecycle of the memory-mapped file, or could it be a synchronization issue? Any insights would be greatly appreciated! I'm working on a mobile app that needs to handle this. Has anyone dealt with something similar? I recently upgraded to C# 3.10.