在c＃中获取属性的名称

Question

Given this class:

public class MyClass
{
    public int MyProperty {get; set;}
}

How will I be able to extract the name of MyProperty in code?

For example, I am able to get the name of the class like this

typeof(MyClass).Name

How can I do something similar for the property?

The reason for the question is that I want this particular code to be resistant against refactorizations of the names.

EDIT: With resistant I mean that I want the code at the call site to be robust in the face of changes of the propertyname. I have some stuff that is using a string representation of the property name. Sorry for the poor phrasing. I did not include call site code in order to keep the problem clean and not wander off into other discussions on the nature of the call site code.

Answer 1

You do it like this, using compiler generated expression trees:

public static string GetMemberName<T, TValue>(Expression<Func<T, TValue>> memberAccess)
{
    return ((MemberExpression)memberAccess.Body).Member.Name;
}

Now call the static method from code:

class MyClass
{
    public int Field;
    public string Property { get; set; }
}

var fieldName = GetMemberName((MyClass c) => c.Field);
var propertyName = GetMemberName((MyClass c) => c.Property);
// fieldName has string value of `Field`
// propertyName has string value of `Property`

You can now also use refactoring to rename that field without breaking this code

Answer 2

In C# 6 we can do it very simply

nameof(MyField);

you can get method\\type\\propery\\field\\class\\namespace names in the same way ex

 nameof(MyClass);
 nameof(namespacename1)  // returns "namespacename1"
 nameof(TestEnum.FirstValue) // returns enum's first value

MSDN Reference

Look at this post

Answer 3

With C# 6.0, you can use the new nameof operator.

nameof(MyClass.MyField)  // returns "MyField"
nameof(MyClass)  //returns "MyClass"

See nameof (C# and Visual Basic Reference) for more examples.

Answer 4

Using Reflection you can find all Members from MyClass with this.

    MemberInfo[] members = typeof(MyClass).GetMembers();

Now you can find your desired property for each Member.

    foreach ( MemberInfo memberInfo in members)
    {
        Console.WriteLine("Name: {0}", memberInfo.Name); // Name: MyField
        Console.WriteLine("Member Type: {0}", memberInfo.MemberType); // Member Type: Property
    }

If you want to find only Properties use PropertyInfo instead of MemberInfo . Or write this

    foreach ( MemberInfo memberInfo in members.Where(p => p.MemberType == MemberTypes.Property))
    {
        Console.WriteLine("Name: {0}", memberInfo.Name); // Name: MyField
        Console.WriteLine("Member Type: {0}", memberInfo.MemberType); // Member Type: Property
    }

Answer 5

You could use the following class which contains a method using an expression tree as an argument to determine a member name based on a lambda expression:

public class MemberHelper<T>
{
    public string GetName<U>(Expression<Func<T, U>> expression)
    {
        MemberExpression memberExpression = expression.Body as MemberExpression;
        if (memberExpression != null)
            return memberExpression.Member.Name;

        throw new InvalidOperationException("Member expression expected");
    }
}

Then use it like so:

MemberHelper<MyClass> memberHelper = new MemberHelper<MyClass>();
string name = memberHelper.GetName(x => x.MyField);

Answer 6

If you only want to get name of an instance member, you can use shorter code:

    public static string GetMemberName<TValue>(Expression<Func<TValue>> memberAccess)
    {
        return ((MemberExpression)memberAccess.Body).Member.Name;
    }

And use it like the following inside the class:

    ReflectionTools.GetMemberName(() => _someInstanceVariableOrProperty)

Answer 7

If you don't want to waste your time , try the following one. I know there will be people run into the same problem.

// Soner - tested!
foreach (PropertyDescriptor descriptor in TypeDescriptor.GetProperties(item))
{
    string name = descriptor.Name;              // Name
    object value = descriptor.GetValue(item);   // Value
    var type = descriptor.PropertyType;         // Type
    Console.WriteLine($"{name}={value}={type}");
}

Don't forget to add using System.ComponentModel; .