代码修复：更改成员和 class 用于方法调用

Question

我正在做一个代码分析器，但我找不到一种方法来更改 class 和调用方法时正在访问的成员。例如，如果我有

public class FirstClass
{
    public static void DoSomething(object SomeParameter)
    {
        //method body 
    }
}
public class SecondClass
{
    public static void ReplaceDoSomething(object SomeParameter)
    {
        //other method's body
    }
}

我怎样才能让我的代码修复更改 FirstClass.DoSomething(new object()); 到 SecondClass.ReplaceDoSomething(new object());？

我尝试使用 SyntaxFactory 但我无法真正弄清楚大多数方法需要哪些参数，MSDN 几乎没有提供有关它们的详细信息...

代码分析器

public override void Initialize(AnalysisContext context)
{
    context.RegisterOperationAction(Analyze, OperationKind.Invocation);
}
private void Analyze(OperationAnalysisContext context)
{
    IInvocationOperation operation = (IInvocationOperation)context.Operation;
    if (operation.TargetMethod.Name == "DoSomething" && operation.TargetMethod.ContainingNamespace.Name == "FirstNamespace" && operation.TargetMethod.ContainingType.Inherits("FirstNamespace.FirstClass"))
    {
        //Rule is an automaticaly generated variable by visual studio when you create the analyzer
        Diagnostic diagnostic = Diagnostic.Create(Rule, operation.Syntax.GetLocation());
        context.ReportDiagnostic(diagnostic);
    }
}
public static class INamedTypeSymbolExtensions
{
    public static bool Inherits(this INamedTypeSymbol first, string otherFullName)
    {
        if (first.GetFullName() == otherFullName)
        {
            return true;
        }
        else if (typeof(object).FullName == first.GetFullName())
        {
            return false;
        }
        else
        {
            return first.BaseType.Inherits(otherFullName);
        }
    }

    public static string GetFullName(this INamedTypeSymbol element)
    {
        StringBuilder ret = new StringBuilder(element.Name);
        INamespaceSymbol ContainingNamespace = element.ContainingNamespace;
        while (ContainingNamespace.ContainingNamespace != null)
        {
            ret.Insert(0, ContainingNamespace.Name + ".");
            ContainingNamespace = ContainingNamespace.ContainingNamespace;
        }
        return ret.ToString();
    }
}

编辑：我得到的最好结果是

private async Task<Document> ProvideCodeFix(Document document, InvocationExpressionSyntax invocation, CancellationToken cancellationToken)
{
    SyntaxToken replaced = invocation.GetFirstToken();
    SyntaxToken replacing = SyntaxFactory.IdentifierName("SecondClass").GetFirstToken().WithLeadingTrivia(replaced.LeadingTrivia));
    return document.WithSyntaxRoot((await document.GetSyntaxRootAsync()).ReplaceToken(replaced, replacing);
}

有了这个，它会将 FirstClass.DoSomething(new object()); 更改为 SecondClass.DoSomething(new object());

但这种方法的主要问题是，如果我必须将 FirstNamespace.FirstClass.DoSomething(new object()); 更改为 SecondClass.ReplaceDoSomething(new object());，那么它将不起作用

PS : 我用 .WithLeadingTrivia(...) 来保留评论和在 FirstClass

之前写的东西

Answer 1

此代码有效。我们得到 InvocationExpressionSyntax.Expression 代表 () 参数列表之前的整个部分。然后我们替换整个表达式。

private async Task<Document> ProvideCodeFix(Document document, InvocationExpressionSyntax invocationExpression, CancellationToken cancellationToken)
{
    // Get the expression that represents the entity that the invocation happens on
    // (In this case this is the method name including possible class name, namespace, etc)
    var invokedExpression = invocationExpression.Expression;

    // Construct an expression for the new classname and methodname
    var classNameSyntax = SyntaxFactory.IdentifierName("SecondClass");
    var methodNameSyntax = SyntaxFactory.IdentifierName("ReplaceDoSomething");
    var classNameAndMethodNameSyntax = SyntaxFactory.MemberAccessExpression(SyntaxKind.SimpleMemberAccessExpression, classNameSyntax, methodNameSyntax);

    // Add the surrounding trivia from the original expression
    var replaced = classNameAndMethodNameSyntax;
    replaced = replaced.WithLeadingTrivia(invokedExpression.GetLeadingTrivia());
    replaced = replaced.WithTrailingTrivia(invokedExpression.GetTrailingTrivia());

    // Replace the whole original expression with the new expression
    return document.WithSyntaxRoot((await document.GetSyntaxRootAsync()).ReplaceNode(invokedExpression, replaced));
}