如何从值中获取字段的 FieldInfo [英] How to get the FieldInfo of a field from the value

问题描述

我想访问 FieldInfo，用于字段上的 CustomAttributes 和其他目的，但我不想使用字符串来访问该字段，也不想遍历类中的所有字段.

I want to access the FieldInfo, for the CustomAttributes that are on a field, and other purposes, but I'd prefer not to use a string to access that field, nor to have to run through all the fields in a class.

如果我只是有，

class MyClass
{
#pragma warning disable 0414, 0612, 0618, 0649
    private int myInt;
#pragma warning restore 0414, 0612, 0618, 0649

    public MyClass()
    {
        BindingFlags flags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic;
        Console.WriteLine( GetType().GetField("myInt", flags) );

        foreach( FieldInfo fi in GetType().GetFields(flags) )
        {
            Console.WriteLine( string.Format("{0} {1} {2}", fi.Name, myInt, fi.GetValue(this) ) );
        }
    }
}

我知道我可以通过GetField"函数直接访问myInt"的FieldInfo，如果我有它的名字的字符串，或者循环通过GetFields"，那将再次依赖于字符串myInt"确保您拥有正确的字段.

I know I can access the FieldInfo of "myInt" directly via the "GetField" function, if I have the string of it's name, or cycling through "GetFields", that would again rely upon having the string "myInt" to ensure you've the right field.

是否有任何可用的魔法，例如 ref myInt 或 out myInt，或者一些我不知道的关键字，它们可以让我访问，还是我仅限于需要字符串名称来获取它?

Is there any sort of magic that's available like ref myInt, or out myInt, or some keyword that I don't know about yet which would give me access, or am I limited to needing the string name to get it?

推荐答案

你的意思是从编译的表达式而不是字符串中获取成员信息?例如

Do you mean getting the memberinfo from a compiled expression rather than the string? e.g

class Program
{
    public static void Main()
    {
        var cls = new MyClass();
        Console.WriteLine(GetMemberInfo(cls, c => c.myInt));
        Console.ReadLine();
    }

    private static MemberInfo GetMemberInfo<TModel, TItem>(TModel model, Expression<Func<TModel, TItem>> expr)
    {
        return ((MemberExpression)expr.Body).Member;
    }

    public class MyClass
    {
        public int myInt;   
    }
}

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