Setting ExtendsContentIntoTitleBar in XAML causes WMC0612

[HO-COOH]

Describe the bug

Setting ExtendsContentIntoTitleBar in XAML causes

Severity	Code	Description	Project	File	Line	Suppression State
Error	WMC0612	The XAML Binary Format (XBF) generator reported syntax error '0x09C4' : Property Not Found	WinUI3Cpp	C:\Users\Peter\Source\Repos\WinUI3Cpp\MainWindow.xaml	11	

Steps to reproduce the bug

1. In MainWindow.xaml, add the property

<Window
    x:Class="WinUI3Cpp.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:WinUI3Cpp"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    ExtendsContentIntoTitleBar="True"
    mc:Ignorable="d">

Expected behavior

No response

Screenshots

No response

NuGet package version

WinUI 3 - Windows App SDK 1.4.2: 1.4.231008000

Windows version

Windows 10 (1809): Build 17763

Additional context

No response

[ghost1372]

This is known issue and duplicate,
You should set it in code-behinde

Window.Extend.... //Or this.Extend...

[HO-COOH]

@ghost1372 I didn't find another open issue about this.

[ghost1372]

@ghost1372 I didn't find another open issue about this.

i cant remember dup issue, but there was same issue for Title and they fixed in v1.3
https://learn.microsoft.com/en-us/windows/apps/windows-app-sdk/stable-channel#version-131-13230502000

[pratikone]

ExtendsContentIntoTitleBar="True" is not supported in markup. It is only supported in code behind in C# /C++. Closing as not an issue.

[HO-COOH]

ExtendsContentIntoTitleBar="True" is not supported in markup. It is only supported in code behind in C# /C++. Closing as not an issue.

Documented nowhere?

[Iridium-IO]

If it's not supported in markup, it shouldn't be in markup