Dotnet-Framework

# .NET Framework Development

Build and Compilation Requirements

- Always use `msbuild /t:rebuild` to build the solution or projects instead of `dotnet build`

Project File Management

Legacy and SDK-Style Project Structure

Many .NET Framework projects use the legacy non-SDK project format, which differs significantly from modern SDK-style projects. However, SDK-style project files can also target .NET Framework, such as `net48` or `net472`. Check the `.csproj` format before applying project-file guidance:

- **Legacy non-SDK projects**: All new source files **MUST** be explicitly added to the project file (`.csproj`) using a `<Compile>` element

- Legacy non-SDK projects do not automatically include files in the directory like SDK-style projects

- Example: `<Compile Include="Path\To\NewFile.cs" />`

- **SDK-style projects**: If the project file has an `Sdk` attribute, use SDK-style conventions even when it targets .NET Framework

- Example: `<Project Sdk="Microsoft.NET.Sdk">`

- Uses `<TargetFramework>` instead of `<TargetFrameworkVersion>`

- Example: `<TargetFramework>net48</TargetFramework>`

- **No Implicit Imports in legacy projects**: Unlike SDK-style projects, legacy non-SDK projects do not automatically import common namespaces or assemblies

- **Build Configuration in legacy projects**: Contains explicit `<PropertyGroup>` sections for Debug/Release configurations

- **Output Paths in legacy projects**: Explicit `<OutputPath>` and `<IntermediateOutputPath>` definitions

- **Target Framework in legacy projects**: Uses `<TargetFrameworkVersion>` instead of `<TargetFramework>`

- Example: `<TargetFrameworkVersion>v4.7.2</TargetFrameworkVersion>`

NuGet Package Management

- Installing and updating NuGet packages in .NET Framework projects is a complex task requiring coordinated changes to multiple files. Therefore, **do not attempt to install or update NuGet packages** in this project.

- Instead, if changes to NuGet references are required, ask the user to install or update NuGet packages using the Visual Studio NuGet Package Manager or Visual Studio package manager console.

- When recommending NuGet packages, ensure they are compatible with .NET Framework or .NET Standard 2.0 (not only .NET Core or .NET 5+).

C# Language Version is 7.3

- This project is limited to C# 7.3 features only. Please avoid using:

C# 8.0+ Features (NOT SUPPORTED):

- Using declarations (`using var stream = ...`)

- Await using statements (`await using var resource = ...`)

- Switch expressions (`variable switch { ... }`)

- Null-coalescing assignment (`??=`)

- Range and index operators (`array[1..^1]`, `array[^1]`)

- Default interface methods

- Readonly members in structs

- Static local functions

- Nullable reference types (`string?`, `#nullable enable`)

C# 9.0+ Features (NOT SUPPORTED):

- Records (`public record Person(string Name)`)

- Init-only properties (`{ get; init; }`)

- Top-level programs (program without Main method)

- Pattern matching enhancements

- Target-typed new expressions (`List<string> list = new()`)

C# 10+ Features (NOT SUPPORTED):

- Global using statements

- File-scoped namespaces

- Record structs

- Required members

Use Instead (C# 7.3 Compatible):

- Traditional using statements with braces

- Switch statements instead of switch expressions

- Explicit null checks instead of null-coalescing assignment

- Array slicing with manual indexing

- Abstract classes or interfaces instead of default interface methods

Environment Considerations (Windows environment)

- Use Windows-style paths with backslashes (e.g., `C:\path\to\file.cs`)

- Use Windows-appropriate commands when suggesting terminal operations

- Consider Windows-specific behaviors when working with file system operations

Common .NET Framework Pitfalls and Best Practices

Async/Await Patterns

- **ConfigureAwait(false)**: Always use `ConfigureAwait(false)` in library code to avoid dea