How does Hot Reload even work?
summary
Explains that hot reload sends small delta compilations (IL + metadata + PDB) rather than full DLLs, with Roslyn computing what changed and emitting an ENC map/log in the PDB so the runtime can apply updates by token ordering, not by stable IDs; shows tools ILSpy and MDV to inspect tables and deltas, and demos generation 1/2 token remapping and method-body swaps. Notes runtime limits (Mono/Blazor WASM only supports method-body updates) and the hack that deleted methods are replaced with stubs that throw MissingMethodException.
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chapters (10)
- 0:00Hot reload in .NET intro
- 1:05What .NET assemblies contain
- 12:45Hot reload model
- 17:17Delta compilation explained
- 26:55Demo: hot reload in action
- 35:47ENC log and map tables
- 41:52Runtime limits and root edits
- 51:38C# features blocking hot reload
- 59:31Modern runtime and Blazor Wasm
- 1:01:16Q&A
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