您可以尝试转换为对象，然后调用 ToString()，而不是尝试转换为字符串:

Instead of trying to cast to string, you could try casting to object then calling ToString(), as though you were doing:

var converted = member.ToString();

作为一个表达式，它看起来像这样:

As an Expression, it will look something like this:

var convertedExpression = Expression.Call(
                     Expression.Convert(memberExpression, typeof(object)),
                     typeof(object).GetMethod("ToString"));