Fix PictureBox frame callback handle race in OnFrameChanged

[LeafShi1]

Fixes #14823

Root Cause

During animated image updates, OnFrameChanged could evaluate InvokeRequired before checking IsHandleCreated.
In rare timing windows (handle create/destroy while animation callback is running), this can lead to unstable handle state and an occasional "Error creating window handle".

Proposed changes

• In PictureBox.OnFrameChanged, check IsHandleCreated first, then InvokeRequired.
  This allows for an immediate short-circuit when the handle does not exist, avoiding the more complex InvokeRequired path (which involves parent chain traversal, thread checks, and race conditions regarding handle state).
  It also ensures consistency with similar controls, such as Label and ButtonBase, which likewise check IsHandleCreated first.

Customer Impact

• Reduces intermittent "Error creating window handle" for apps using animated images in PictureBox.

Regression?

• No

Risk

• Minimal

Test methodology

• Manually

Test environment(s)

• .net11.0.0-preview.7.26365.101

Microsoft Reviewers: Open in CodeFlow

[Copilot]

Pull request overview

This PR addresses an intermittent Win32Exception: Error creating window handle seen during PictureBox animated image frame callbacks by reducing handle-state race exposure in OnFrameChanged.

Changes:

• Reordered the conditional in PictureBox.OnFrameChanged to check IsHandleCreated before evaluating InvokeRequired, avoiding the more complex InvokeRequired path when there is no handle.

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[SimonZhao888]

Looks good to me!

[ricardobossan]

ALL LGTM!