如何使用NRefactory修改C＃代码

Question

我正在尝试使用NRefactory来修改现有的C＃代码。我试图使用this article中描述的方法。我有一个例外，抱怨重复的更改。有人可以指出我做错了什么，并且可能指出我正确的方向吗？

我有以下代码部分：

// contains the source code that needs to be modified
var text = "...";
// is the name of the file in which the target class exists
var fileName = "Foo";
// is the name of the target class
var className = "Foo.cs"; 

// FormattingOptions and TextEditorOptions are properties available to
// the class containing this code...

var parser = new CSharpParser();

var syntaxTree = parser.Parse(text, fileName);

syntaxTree.Freeze();

var document = new StringBuilderDocument();

document.Text = syntaxTree.ToString(FormattingOptions);

using (var documentScript = new DocumentScript(document, FormattingOptions, TextEditorOptions))
{
    var typeDeclarations = syntaxTree.Descendants.OfType<TypeDeclaration>().Where(typeDeclaration => typeDeclaration.Name == className);
    var templateProviderDeclaration = typeDeclarations.SingleOrDefault();

    if (templateProviderDeclaration != null)
    {
        var constructorDeclarations = templateProviderDeclaration.Descendants.OfType<ConstructorDeclaration>();

        foreach (var constructorDeclaration in constructorDeclarations)
        {
            var assignmentExpressions = constructorDeclaration.Descendants.OfType<AssignmentExpression>();

            foreach (var assignmentExpression in assignmentExpressions)
            {
                var leftExpression = assignmentExpression.Left;

                if (leftExpression != null && leftExpression.ToString(FormattingOptions) == "this.templates")
                {
                    var rightExpression = assignmentExpression.Right;

                    foreach (var arrayInitializerExpression in rightExpression.Children.OfType<ArrayInitializerExpression>())
                    {
                        // uses AddTemplate(), which is an extension method
                        // which takes in an expression and modifies it, and
                        // returns an expression
                        var newExpression = ((ArrayInitializerExpression)arrayInitializerExpression).AddTemplate();

                        documentScript.Replace(arrayInitializerExpression, newExpression);
                    }
                }
            }
        }
    }

    // text retrieved here is *clobbered*, by a few characters
    text = documentScript.CurrentDocument.Text;
}

其他代码......

public static class ExtensionMethods
{
    public static ArrayInitializerExpression AddTemplate(this ArrayInitializerExpression expression)
    {
        // TODO : will modify the AST for the target expression

        return (ArrayInitializerExpression)expression.Clone();
    }
}

更新

我正在尝试更改这样的一行：

this.templates = new Dictionary<string, ITemplate>
{
    { "Foo", new FooTemplate() }
};

为：

this.templates = new Dictionary<string, ITemplate>
{
    { "Foo", new FooTemplate() },
    { "Bar", new BarTemplate() }
};

就本问题而言，我试图做出的改变的具体细节并不重要。我怀疑我的东西构造得不正确，但我无法弄清楚这是不是问题。