Proposal:When should SystemBackdropElement be added to built-in controls, such as ToolTip, TeachingTip, and so on?

[Gaoyifei1011]

Title

When should SystemBackdropElement be added to built-in controls, such as ToolTip, TeachingTip, and so on?

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什么时候为内置控件添加 SystemBackdropElement，例如 ToolTip，TeachingTip 等等？

Summary

When should SystemBackdropElement be added to built-in controls, such as ToolTip, TeachingTip, and so on?

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什么时候为内置控件添加 SystemBackdropElement，例如 ToolTip，TeachingTip 等等？

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In the latest Windows App SDK 2.0-exp4 preview, a new control called SystemBackdropElement has been added to allow controls to use the SystemBackdrop feature. However, some built-in controls still use a solid color background in the latest exp4 and have not adopted the new SystemBackdrop feature. When will these built-in controls receive the SystemBackdrop?

Affected controls: ToolTip, TeachingTip, DatePicker, ComboBox, CommandBar.SecondaryCommands, TimePicker, CalendarDatePicker, NavigationView

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目前在最新的 Windows App SDK 2.0-exp4 预览版中新增了 SystemBackdropElement 这一控件用以为控件添加 SystemBackdrop 这一特性，然而部分内置控件到最新的 exp4 仍然使用纯色背景，没有添加最新的 SystemBackdrop。什么时候为这些内置控件添加 SystemBackdrop？

影响的控件：ToolTip，TeachingTip，DatePicker，ComboBox，CommandBar.SecondaryCommands，TimePicker，CalendarDatePicker，NavigationView

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Effect Graph(效果图)

Rationale

None

Scope

Capability	Priority
This proposal will allow developers to accomplish W	Must
This proposal will allow end users to accomplish X	Should
This proposal will allow developers to accomplish Y	Could
This proposal will allow end users to accomplish Z	Won't

Important Notes

None

Open Questions

No response

[HO-COOH]

WinUI3体验服（迫真）

Don't expect anything from the Microsoft WinUI3 team until they go fully open-source the whole framework. And until then, if you want Acrylic for the built-in controls, see my repo

[JanviMahajan14]

@godlytalias , can you please check this issue ?

[Jay-o-Way]

Ideally and generally, you should stick to defaults. As far as I know, that new SystemBackdropElement should be used in rare cases, only when you want to override the defaults.

[Gaoyifei1011]

Ideally and generally, you should stick to defaults. As far as I know, that new SystemBackdropElement should be used in rare cases, only when you want to override the defaults.

However, that is not the case. SystemBackdropElement is an advanced wrapper around the ContentExternalBackdropLink API, and any SystemBackdrop you see on WinUI 3 is built on top of this API. The WASDK team has currently only added SystemBackdrop to MenuFlyout and CommandBarFlyout, and if you look through their source code, you will find that they are all implemented using the ContentExternalBackdropLink API. Therefore, Microsoft has the responsibility to keep the background colors of these controls consistent in WinUI 2 or WinUI 3, whether you use the ContentExternalBackdropLink API directly or call SystemBackdropElement.

然而并不是。SystemBackdropElement 是对 ContentExternalBackdropLink API 的一个高级包装，你在 WinUI 3 上看到的任何 SystemBackdrop 都是在这个 API 的基础上实现的。WASDK 团队目前只在 MenuFlyout，CommandBarFlyout 上面添加了SystemBackdrop，如果您翻看它的源代码，就会发现它们都是由 ContentExternalBackdropLink API 实现的。所以 MS 有责任保持这些控件的背景色在 WinUI 2 或 WinUI 3 一致，不管是直接使用 ContentExternalBackdropLink API，还是调用 SystemBackdropElement

https://github.com/microsoft/microsoft-ui-xaml/blob/15af68ea1b6ca7ac3f768084b3bcfdac257b6fab/src/controls/dev/CommandBarFlyout/CommandBarFlyoutCommandBar.h#L[144](https://github.com/microsoft/microsoft-ui-xaml/blob/15af68ea1b6ca7ac3f768084b3bcfdac257b6fab/src/controls/dev/CommandBarFlyout/CommandBarFlyoutCommandBar.h#L144)

https://github.com/microsoft/microsoft-ui-xaml/blob/15af68ea1b6ca7ac3f768084b3bcfdac257b6fab/src/dxaml/xcp/core/inc/Popup.h#L[438](https://github.com/microsoft/microsoft-ui-xaml/blob/15af68ea1b6ca7ac3f768084b3bcfdac257b6fab/src/dxaml/xcp/core/inc/Popup.h#L438)

[Jay-o-Way]

Oh i'm sorry, you seem to know all about it already.

Apparently I am a bit mistaken or confused. What's the real issue here? Do you expect every single surface (to be able) to use mica or acrylic? That would be weird.

In any case, Exp4 is, as the name implies, stil in experimental phase.

[Gaoyifei1011]

Oh i'm sorry, you seem to know all about it already.

Apparently I am a bit mistaken or confused. What's the real issue here? Do you expect every single surface (to be able) to use mica or acrylic? That would be weird.

In any case, Exp4 is, as the name implies, stil in experimental phase.

The controls I mentioned, WinUI 2 (UWP) has a SystemBackdrop with Acrylic (implemented by UWP), while WinUI 3 is solid color. You can download WinUI 2 Gallery and WinUI 3 Gallery for comparison. Moreover, the SystemBackdropElement API in EXP5 / Preview1 is considered a stable version API.

我提到的那些控件，WinUI 2(UWP) 带有 Acrylic 的 SystemBackdrop（由 UWP 实现），WinUI 3 是纯色，您可以下载 WinUI 2 Gallery 和 WinUI 3 Gallery 进行对比。而且，SystemBackdropElement API 在 EXP5 / Preview1 属于稳定版本 API