winui3 C++隐藏右上角三个标题栏按钮

在WinUI 3中，如果你想要隐藏Windows应用中的右上角三个标题栏控制按钮（如最大化、最小化和关闭按钮），你需要在XAML中设置`WindowStyle`属性，并在C++中处理相关的消息处理。以下是步骤：

1. XAML部分：

<Window x:Class="YourNamespace.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        WindowStyle="None" Title="Title" Height="450" Width="800">
    <!-- ... -->
</Window>

这里设置了`WindowStyle`属性为`None`，表示窗口没有传统的边框和标题栏控件。

2. C++部分（C++/WinRT）：

#include "winrt/UI.Xaml.Controls.h"

// ...

ref class MainWindow sealed : public Windows::UI::Xaml::Controls::Window
{
public:
    MainWindow() :
        InitializeComponent()
    {
        // 添加事件处理器以防止默认的行为
        auto windowSizeChangedHandler = ref new Windows::Foundation::TypedEventHandler<Windows::UI::Core::CoreApplicationView^, Windows::UI::Core::WindowSizeChangedEventArgs^>([this](auto sender, auto args) {
            if (args->SizeChangedType == Windows::UI::Core::WindowSizeChangeKind::Maximized)
                ResizeAndLayout();
        });

        auto maximizeButtonTappedHandler = ref new UI::Xaml::Media::Interaction::ButtonBaseTappedEventHandler(this, &MainWindow::OnMaximizeButtonTapped);
        auto minimizeButtonTappedHandler = ref new UI::Xaml::Media::Interaction::ButtonBaseTappedEventHandler(this, &MainWindow::OnMinimizeButtonTapped);
        auto closeButtonTappedHandler = ref new UI::Xaml::Media::Interaction::ButtonBaseTappedEventHandler(this, &MainWindow::OnCloseButtonTapped);

        // 获取窗口的框架
        auto frame = GetElementByIdName("ContentFrame");
        if (frame)
        {
            // 注册事件处理程序
            frame->SizeChanged += windowSizeChangedHandler;
            frame->GotFocus += [maximizeButtonTappedHandler](auto sender, auto args) {
                sender->FindName("MaximizeButton")->Visibility = Windows::UI::Xaml::Visibility::Collapsed; // 隐藏最大化按钮
                sender->FindName("MinimizeButton")->Visibility = Windows::UI::Xaml::Visibility::Collapsed; // 隐藏最小化按钮
            };
            frame->LostFocus += [closeButtonTappedHandler](auto sender, auto args) {
                sender->FindName("MaximizeButton")->Visibility = Windows::UI::Xaml::Visibility::Visible;
                sender->FindName("MinimizeButton")->Visibility = Windows::UI::Xaml::Visibility::Visible;
            };

            // 当前窗口获取焦点时隐藏按钮
            this->GotFocus += maximizeButtonTappedHandler;
            this->GotFocus += minimizeButtonTappedHandler;
            this->GotFocus += closeButtonTappedHandler;

            // 当失去焦点时显示按钮
            this->LostFocus += maximizeButtonTappedHandler;
            this->LostFocus += minimizeButtonTappedHandler;
            this->LostFocus += closeButtonTappedHandler;
        }
    }

private:
    void OnMaximizeButtonTapped(Platform::Object^ sender, Platform::Object^ /*e*/) { } // 实现点击事件逻辑
    void OnMinimizeButtonTapped(Platform::Object^ sender, Platform::Object^ /*e*/) { } 
    void OnCloseButtonTapped(Platform::Object^ sender, Platform::Object^ /*e*/) { }

    // ... 其他窗口初始化和布局代码
};

// 使用静态成员函数注册窗体实例
void RegisterWindow()
{
    auto app = Windows::ApplicationModel::Core::CoreApplication::Current();
    auto mainPage = MainPage::Current();
    if (mainPage)
    {
        mainPage->Window = ref new MainWindow();
    }
}

记得替换`OnMaximizeButtonTapped`、`OnMinimizeButtonTapped` 和 `OnCloseButtonTapped` 方法以实现自定义的按钮行为。同时，确保在适当的地方注册窗体实例。