Version introduced: .NET 10 Preview 1

Form.OnClosing,Form.OnClosed and the corresponding events are obsolete. UseForm.OnFormClosing,Form.OnFormClosed,Form.FormClosing andForm.FormClosed instead.

These methods and events are provided for backwards compatibility and they shouldn't be used. Instead, reference the replacement methods and events.

Workaround

Replace the obsolete member with the new member:

Suppress a warning

Suppress the warning with either of the following methods:

• Set the severity of the rule in the.editorConfig file.

  [*.{cs,vb}]dotnet_diagnostic.WFDEV004.severity = none

  For more information about editor config files, seeConfiguration files for code analysis rules.

• Add the followingPropertyGroup to your project file:

  <PropertyGroup>    <NoWarn>$(NoWarn);WFDEV004</NoWarn></PropertyGroup>

• Suppress in code with the#pragma warning disable WFDEV004 directive.

For more information, seeHow to suppress code analysis warnings.