如何找出表达式指定的类型？

发布于 2024-09-14 05:53:07 字数 175 浏览 5 评论 0原文

例如，假设我有一个方法，它将以下内容作为参数：

Expression<Func<T, object>> path

如何确定表达式中指定的“对象”的类型？更具体地说，我想确定它是否是集合类型（例如IEnumerable）

原文

For example, let's say I have a method that takes the following as a parameter:

Expression<Func<T, object>> path

How do I determine the type of the 'object' specified in the expression? More specifically, I'd like to determine if it's a collection type (eg. IEnumerable)

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

饮湿 2024-09-21 05:53:07

您已经在使用泛型，为什么不继续使用呢？

void GetMemberType<TArg, TProperty>(Expression<Func<TArg, TProperty>> path)
{
    // Get the member ...
    var member = path.Body as MemberExpression;

    // ... Do whatever you want with the member ...

    // Now get the type
    var memberType = typeof(TProperty);
}

You're already using generics, so why not go all the way?

void GetMemberType<TArg, TProperty>(Expression<Func<TArg, TProperty>> path)
{
    // Get the member ...
    var member = path.Body as MemberExpression;

    // ... Do whatever you want with the member ...

    // Now get the type
    var memberType = typeof(TProperty);
}

回复收藏 0 原文

和影子一齐双人舞 2024-09-21 05:53:07

或者，您可以执行类似以下操作（这更符合您的泛型类型参数）：

// Get your expression
// (probably already provided as an arg to one of your methods, I'm willing to bet)
Expression<Func<T, object>> path = ...

var memberExpr = path.Body as MemberExpression;
var member = memberExpr.Member;

Type type;

if (member is FieldInfo)
{
    var field = member as FieldInfo;
    type = field.FieldType;
}

if (member is PropertyInfo)
{
    var property = member as PropertyInfo;
    type = property.PropertyType;
}

Alternatively, you could do something like the following (which is more inline with you generic type arguments):

// Get your expression
// (probably already provided as an arg to one of your methods, I'm willing to bet)
Expression<Func<T, object>> path = ...

var memberExpr = path.Body as MemberExpression;
var member = memberExpr.Member;

Type type;

if (member is FieldInfo)
{
    var field = member as FieldInfo;
    type = field.FieldType;
}

if (member is PropertyInfo)
{
    var property = member as PropertyInfo;
    type = property.PropertyType;
}

回复收藏 0 原文