Question

我使用Roslyn的CSharpSyntaxRewriter来重写以下内容：

string myString = "Hello ";
myString += "World!";

为：

string myString = "Hello ";
myString += "World!"; Log("myString", myString);

我的语法重写器会覆盖VisitAssignmentExpression，如下所示。

public override SyntaxNode VisitAssignmentExpression(AssignmentExpressionSyntax node)
{
    //Construct a new node without trailing trivia
    var newNode = node.WithoutTrailingTrivia();
    InvocationExpressionSyntax invocation = //Build proper invocation

    //Now what? I need to bundle up newNode and invocation and return them
    //as an expression syntax
}

我能够＆＃34;欺骗＆＃34;通过构造缺少大括号的StatementSyntax来处理BlockSyntax时的此限制：

var statements = new SyntaxList<StatementSyntax>();
//Tried bundling newNode and invocation together
statements.Add(SyntaxFactory.ExpressionStatement(newNode));
statements.Add(SyntaxFactory.ExpressionStatement(invocation));
var wrapper = SyntaxFactory.Block(statements);

//Now we can remove the { and } braces
wrapper = wrapper.WithOpenBraceToken(SyntaxFactory.MissingToken(SyntaxKind.OpenBraceToken))
    .WithCloseBraceToken(SyntaxFactory.MissingToken(SyntaxKind.CloseBraceToken)

然而，这种方法无法与AssignmentExpressionSyntax一起使用，因为BlockSyntax无法投放到ExpressionSyntax。（The CSharpSyntaxRewriter tries to make this cast.）

如何将一个SyntaxNode重写为两个SyntaxNodes？

我是否遇到了API的限制，或者有没有类似上述人员可以分享的技巧？

Answer 1

您需要访问父ExpressionStatementSyntax并将其替换为BlockSyntax。

您不能在表达式语句中插入BlockSyntax作为表达式。

将SyntaxNode重写为两个SyntaxNodes

1 个答案: