Roslyn 分析器代码修复提供程序替换文档中的字符串

Question

我已识别出一个节点，该节点的字符串中包含我的分析器正确识别的值。然后我创建了一个可以成功检索字符串的 CodeFixProvider，然后我想替换字符串的某个部分。我现在想替换文档中的字符串来修复警告。我怎样才能最好地应用此修复？

    public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
    {
        var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);

        var diagnostic = context.Diagnostics.First();
        var diagnosticSpan = diagnostic.Location.SourceSpan;

        // Find the type declaration identified by the diagnostic.
        var declaration = root.FindToken(diagnosticSpan.Start).Parent.AncestorsAndSelf().OfType<LiteralExpressionSyntax>().First();

        // Register a code action that will invoke the fix.
        context.RegisterCodeFix(
            CodeAction.Create(
                title: regex,
                createChangedSolution: c => ReplaceRegexAsync(context.Document, declaration, c),
                equivalenceKey: regex),
            diagnostic);
    }

    private async Task<Solution> ReplaceRegexAsync(Document document, LiteralExpressionSyntax typeDecl, CancellationToken cancellationToken)
    {
        var identifierToken = typeDecl.Token;

        var updatedText = identifierToken.Text.Replace("myword", "anotherword");

        // Todo how to replace original text to apply fix
    }

Answer 1

• 最好不要使用CodeAction.Create 签名和createChangedSolution，而是createChangedDocument。它允许在解决方案中注册修补单个文档的修复程序。
• 您需要通过修改SyntaxTree 或SourceText 将更改应用到文档

...
context.RegisterCodeFix(
    CodeAction.Create(
        title: regex,
        createChangedDocument:c => ReplaceRegexAsync(context.Document, declaration, c),
        equivalenceKey: regex),
    diagnostic);

private async Task<Document> ReplaceRegexAsync(Document document, LiteralExpressionSyntax typeDecl, CancellationToken cancellationToken)
{
    var identifierToken = typeDecl.Token;

    var updatedText = identifierToken.Text.Replace("myword", "anotherword");
    var valueText = identifierToken.ValueText.Replace("myword", "anotherword");
    var newToken = SyntaxFactory.Literal(identifierToken.LeadingTrivia, updatedText, valueText, identifierToken.TrailingTrivia);

    var sourceText = await typeDecl.SyntaxTree.GetTextAsync(cancellationToken);
    // update document by changing the source text
    return document.WithText(sourceText.WithChanges(new TextChange(identifierToken.FullSpan, newToken.ToFullString())));
}