designing-wpf-customcontrol-architecture

# XAML Code Writing - WPF CustomControl

A guide for using CustomControl and ResourceDictionary when writing XAML code in WPF.

## Project Structure

The templates folder contains a .NET 9 WPF project example.

```
templates/
├── WpfCustomControlSample.Controls/        ← WPF Custom Control Library
│   ├── Properties/
│   │   └── AssemblyInfo.cs
│   ├── Themes/
│   │   ├── Generic.xaml                    ← MergedDictionaries hub
│   │   └── CustomButton.xaml               ← Individual control style
│   ├── CustomButton.cs
│   ├── GlobalUsings.cs
│   └── WpfCustomControlSample.Controls.csproj
└── WpfCustomControlSample.App/             ← WPF Application
    ├── Views/
    │   ├── MainWindow.xaml
    │   └── MainWindow.xaml.cs
    ├── App.xaml
    ├── App.xaml.cs
    ├── GlobalUsings.cs
    └── WpfCustomControlSample.App.csproj
```

## Basic Principles

**When generating XAML code, use CustomControl with Stand-Alone Control Style Resource through ResourceDictionary**

**Purpose**: Fix the timing of StaticResource loading and minimize style dependencies

## WPF Custom Control Library Project Structure

### Default Structure When Creating Project

```
YourProject/
├── Dependencies/
├── Themes/
│   └── Generic.xaml
├── AssemblyInfo.cs
└── CustomControl1.cs
```

### Restructure to Recommended Project Structure

```
YourProject/
├── Dependencies/
├── Properties/
│   └── AssemblyInfo.cs          ← Moved
├── Themes/
│   ├── Generic.xaml             ← Use as MergedDictionaries hub
│   ├── CustomButton.xaml        ← Individual control style
│   └── CustomTextBox.xaml       ← Individual control style
├── CustomButton.cs
└── CustomTextBox.cs
```

## Step-by-Step Setup

### 1. Create Properties Folder and Move AssemblyInfo.cs

- Create Properties folder in the project
- Move AssemblyInfo.cs to the Properties folder

### 2. Configure Generic.xaml - Use as MergedDictionaries Hub

Generic.xaml does not define styles directly; it only performs the role of merging individual ResourceDi