使用 Roslyn 拆分表达式语句

Question

我正在开发一个重述 CSharp 代码的应用程序。我用 Roslyn 来做这个。我遇到了 splitting expressions.

的问题

示例类

class Program
{
    static void Main(string[] args)
    {
        float floatVariable = 20;
        Int16 intVariable = 10;
        string str = "School";
        Console.Write(str + floatVariable.ToString() + intVariable.ToString()); // Facing problem with this statement
    }
}

我正在使用的示例代码

string code = new StreamReader(classPath).ReadToEnd();
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var syntaxRoot = syntaxTree.GetRoot();

//This will get the method and local variables declared inside the method
var MyMethods = syntaxRoot.DescendantNodes().OfType<MethodDeclarationSyntax>();
foreach (MethodDeclarationSyntax mds in MyMethods)
{
    syntaxTree = CSharpSyntaxTree.ParseText(mds.ToFullString());
    IEnumerable<SyntaxNode> nodes = syntaxTree.GetRoot().DescendantNodes();
    IEnumerable<VariableDeclarationSyntax> variableDeclarations =       nodes.OfType<VariableDeclarationSyntax>();
    foreach (VariableDeclarationSyntax variable in variableDeclarations)
    {
    // I will collect the variable details like Datatype, variable names and initialized values  here
    }


    foreach (StatementSyntax statement in mds.Body.Statements)
    {
        if (statement.CSharpKind() == SyntaxKind.ExpressionStatement)
        {
            //I want to split the expressions "Console.Write(str + floatVariable.ToString() + intVariable.ToString());" as below

            //1. intVariable.ToString()
            //2. floatVariable.ToString()
            //3. str

            //Then I have to find the whole data type from the resolved result of above 3 => string here            
        }
    }
}

我们将不胜感激。

编辑： 我在拆分参数化表达式语句时遇到问题。我正在尝试通过

来做到这一点

if (statement.CSharpKind() == SyntaxKind.ExpressionStatement)
{
    ExpressionStatementSyntax expression = statement as ExpressionStatementSyntax;
    var expressions = expression.Expression.DescendantNodes();
}

但这会将每个标记拆分为单独的元素。我只想将 Console.Write(str + floatVariable.ToString() + intVariable.ToString()) 拆分为

Console.Write()
海峡
intVariable.ToString()
floatVariable.ToString()

Answer 1

很难说出你到底想做什么，因为你只指定了代码在一种特定情况下应该做什么，而不是在一般情况下。

我的理解是：

对于调用表达式，return 被调用的表达式，如果有的话，也会下降到它的参数中。
对于二元运算符，下降到 children。
对于所有其他表达式，return 直接表达式。

使用此规范并使用 CSharpSyntaxVisitor，代码可能如下所示：

public static IEnumerable<ExpressionSyntax> Split(ExpressionSyntax expression)
{
    return new SplitVisitor().Visit(expression);
}

class SplitVisitor : CSharpSyntaxVisitor<IEnumerable<ExpressionSyntax>>
{
    public override IEnumerable<ExpressionSyntax> VisitInvocationExpression(
        InvocationExpressionSyntax node)
    {
        yield return node.Expression;

        var argumentExpressions = node.ArgumentList.Arguments
            .SelectMany(a => Visit(a.Expression));
        foreach (var expression in argumentExpressions)
            yield return expression;
    }

    public override IEnumerable<ExpressionSyntax> VisitBinaryExpression(
        BinaryExpressionSyntax node)
    {
        foreach (var expression in Visit(node.Left))
            yield return expression;
        foreach (var expression in Visit(node.Right))
            yield return expression;
    }

    public override IEnumerable<ExpressionSyntax> DefaultVisit(SyntaxNode node)
    {
        var expression = node as ExpressionSyntax;
        if (expression != null)
            yield return expression;
    }
}

使用 Roslyn 拆分表达式语句

Splitting the Expression statements with Roslyn

c#

visual-studio

roslyn