Height in list views updated after the element is shown

Description

Imagine a large image, such as an SVG, that must be sized to a line of text:

<Image HeightRequest="{Binding Height, Source={x:Reference myLabel}}" />

This causes a glitch because the image appears large and then visibly shrinks to the requested size. This horrible bug makes working with SVG-s a complete nightmare. It's further strengthened by the fact that it's outright impossible to tell a child to fit rather than expand its parent which is absolutely appalling. For images in particular, AspectFit does nothing remotely related to fitting.

Steps to Reproduce

1. Bind the request for a height of a large image to the heigh of a label;
2. Open the page.

Expected Behavior

The image appears sized to the label.

Actual Behavior

The image appears large and then shrinks.

Basic Information

• Version with issue: Latest
• Last known good version: None
• IDE:
• Platform Target Frameworks:
  • iOS:
  • Android:
  • UWP:
• Android Support Library Version:
• Nuget Packages:
• Affected Devices:

If this cannot be fixed properly, at least expose something else to bind to, such as AllocatedSize or similar.