WinForms Expert

# WinForms Development Guidelines

These are the coding and design guidelines and instructions for WinForms Expert Agent development.
When customer asks/requests will require the creation of new projects

**New Projects:**
* Prefer .NET 10+. Note: MVVM Binding requires .NET 8+.
* Prefer `Application.SetColorMode(SystemColorMode.System);` in `Program.cs` at application startup for DarkMode support (.NET 9+).
* Make Windows API projection available by default. Assume 10.0.22000.0 as minimum Windows version requirement.
```xml
    <TargetFramework>net10.0-windows10.0.22000.0</TargetFramework>
```

**Critical:**

**📦 NUGET:** New projects or supporting class libraries often need special NuGet packages. 
Follow these rules strictly:
 
* Prefer well-known, stable, and widely adopted NuGet packages - compatible with the project's TFM.
* Define the versions to the latest STABLE major version, e.g.: `[2.*,)`

**⚙️ Configuration and App-wide HighDPI settings:** *app.config* files are discouraged for configuration for .NET.
For setting the HighDpiMode, use e.g. `Application.SetHighDpiMode(HighDpiMode.SystemAware)` at application startup, not *app.config* nor *manifest* files.

Note: `SystemAware` is standard for .NET, use `PerMonitorV2` when explicitly requested.

**VB Specifics:**
- In VB, do NOT create a *Program.vb* - rather use the VB App Framework.
- For the specific settings, make sure the VB code file *ApplicationEvents.vb* is available. 
  Handle the `ApplyApplicationDefaults` event there and use the passed EventArgs to set the App defaults via its properties.

| Property | Type | Purpose | 
|----------|------|---------|
| ColorMode | `SystemColorMode` | DarkMode setting for the application. Prefer `System`. Other options: `Dark`, `Classic`. |
| Font | `Font` | Default Font for the whole Application. |	
| HighDpiMode | `HighDpiMode` | `SystemAware` is default. `PerMonitorV2` only when asked for HighDPI Multi-Monitor scenarios. |

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## 🎯 Critical Generic WinForms Issue: Dealing with Two Code Contexts

| Context | Files/Location | Language Level | Key Rule |
|---------|----------------|----------------|----------|
| **Designer Code** | *.designer.cs*, inside `InitializeComponent` | Serialization-centric (assume C# 2.0 language features) | Simple, predictable, parsable |
| **Regular Code** | *.cs* files, event handlers, business logic | Modern C# 11-14 | Use ALL modern features aggressively |

**Decision:** In *.designer.cs* or `InitializeComponent` → Designer rules. Otherwise → Modern C# rules.

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