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 Add analyzer to warn when using required or init on Blazor component parameters
 #63822
 
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 Greetings human! You've submitted a PR that modifies code that is shared with https://github.com/dotnet/runtime . Please make sure you synchronize this code with the changes in that repo!
 
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 ...ponent parameters Co-authored-by: javiercn <6995051+javiercn@users.noreply.github.com>
...ting Co-authored-by: javiercn <6995051+javiercn@users.noreply.github.com>
Co-authored-by: javiercn <6995051+javiercn@users.noreply.github.com>
 
 
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(削除) [WIP] [Blazor] Analyzer to warn when using 
(追記) Add analyzer to warn when using Sep 25, 2025 
 
 required or init on Blazor component properties (削除ここまで)required or init on Blazor component parameters (追記ここまで)
  
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Adds a new analyzer (BL0010) that warns developers when using
requiredorinitmodifiers on Blazor component parameter properties, addressing issues reported in #47824 and #44974.Problem
Customers have been attempting to use the
requiredmodifier on Blazor component parameters to ensure parameters have values, but this doesn't work as expected because:ParameterView.SetParameterProperties(), which bypassesrequiredrestrictionsrequiredmodifier makes nullability warnings disappear but provides no actual guaranteesrequired/initcould cause compilation errorsSolution
The new analyzer detects both
requiredandinitmodifiers on[Parameter]properties and suggests using the[EditorRequired]attribute instead:Implementation Details
required/initmodifiers on[Parameter]properties[EditorRequired]attribute as the proper alternativeThe analyzer integrates seamlessly with the existing ASP.NET Core analyzer infrastructure and follows established patterns for diagnostic reporting and localization.
Fixes #48051
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