interface ICoreWebView2Controller2

Artikel
04/22/2021

Note

This reference is no longer being maintained. For the latest API reference, see WebView2 API Reference.

interface ICoreWebView2Controller2
  : public ICoreWebView2Controller

A continuation of the ICoreWebView2Controller interface.

Summary

Members	Descriptions
get_DefaultBackgroundColor	The `DefaultBackgroundColor` property allows developers to set the color that shows when WebView has not loaded any web content and when a webpage does not specify a background color.
put_DefaultBackgroundColor	Sets the `DefaultBackgroundColor` property.

Applies to

Product	Introduced
WebView2 Win32	1.0.774.44
WebView2 Win32 Prerelease	1.0.790

Members

get_DefaultBackgroundColor

The DefaultBackgroundColor property allows developers to set the color that shows when WebView has not loaded any web content and when a webpage does not specify a background color.

public HRESULT get_DefaultBackgroundColor(COREWEBVIEW2_COLOR * backgroundColor)

Color is specified by the COREWEBVIEW2_COLOR value meaning the background color can also be transparent. The WebView background color will show before the initial navigation, between navigations before the next page has rendered, and for pages with no background style properties set. To clarify the latter case, WebView will always honor a webpage's background content. DefaultBackgroundColor will only show in the absence of css background style properties. In that case, WebView will render web content over the DefaultBackgroundColor color. For a transparent background, web content will render over hosting app content. WebView's default background color is white to resemble the browser experience. It is important to note that while COREWEBVIEW2_COLOR has A an alpha value, semi-transparent colors are not supported by this API and setting DefaultBackgroundColor to a semi-transparent color will fail with E_INVALIDARG. The only supported alpha values are 0 and 255, all other values will result in E_INVALIDARG. DefaultBackgroundColor can only be an opaque color or transparent.

The DefaultBackgroundColor property enables a smoother UI experience. Developers can choose the color that shows between loading pages and eliminate any 'white flash.' For websites with no specified background color, developers can display web contents over a color of their choosing. They can also do away with the background color entirely with transparency and have the 'in between pages color' just be hosting content, or have hosting app content be the backdrop for webpages without a background color specified.

void ViewComponent::SetBackgroundColor(COLORREF color, bool transparent)
{
    COREWEBVIEW2_COLOR wvColor;
    wvColor.R = GetRValue(color);
    wvColor.G = GetGValue(color);
    wvColor.B = GetBValue(color);
    wvColor.A = transparent ? 0 : 255;
    wil::com_ptr<ICoreWebView2Controller2> controller2 =
        m_controller.query<ICoreWebView2Controller2>();
    controller2->put_DefaultBackgroundColor(wvColor);
}

put_DefaultBackgroundColor

Sets the DefaultBackgroundColor property.

public HRESULT put_DefaultBackgroundColor(COREWEBVIEW2_COLOR backgroundColor)

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