C# Reflection - Get PropertyInfo without a string [duplicate]

问题:

This question already has an answer here:

• How to get the PropertyInfo of a specific property? 4 answers

I have a property in Myclass:

public class MyClass{         public string FirstName {get;set;} } 

How can I get the PropertyInfo (using GetProperty("FirstName")) without a string?

Today I use this:

PropertyInfo propertyTitleNews = typeof(MyClass).GetProperty("FirstName"); 

Is there a way for use like this:

PropertyInfo propertyTitleNews = typeof(MyClass).GetProperty(MyClass.FirstName); 

?

回答1:

See here. The idea is to use Expression Trees.

public static string GetPropertyName<T, TReturn>(Expression<Func<T, TReturn>> expression) {     MemberExpression body = (MemberExpression)expression.Body;     return body.Member.Name; } 

And then use it like:

var name = GetPropertyName<MyClass, string>(c => c.FirstName); 

A bit cleaner solution would be if one would not required to specify so much generic parameters. And it is possible via moving MyClass generic param to util class:

public static class TypeMember<T> {     public static string GetPropertyName<TReturn>(Expression<Func<T, TReturn>> expression)     {         MemberExpression body = (MemberExpression)expression.Body;         return body.Member.Name;     } } 

Then usage will be cleaner:

var name = TypeMember<MyClass>.GetPropertyName(c => c.FirstName); 

回答2:

Another possibility, beside Ivan Danilov's answer, is to provide an extension method:

public static class PropertyInfoExtensions {     public static string GetPropertyName<TType, TReturnType>(         this TType @this,         Expression<Func<TType, TReturnType>> propertyId)     {         return ((MemberExpression)propertyId.Body).Member.Name;     } } 

And then use it like this:

MyClass c; PropertyInfo propertyTitleNews = c.GetPropertyName(x => x.FirstName); 

The drawback is that you need an instance, but an advantage is that you don't need to supply generic arguments.

回答3:

You could do that

var property = ExpressionExtensions.GetProperty<MyClass>(o => o.FirstName); 

With this helper :

public static PropertyInfo GetProperty<T>(Expression<Func<T, Object>> expression) {      MemberExpression body = (MemberExpression)expression.Body;      return typeof(T).GetProperty(body.Member.Name); } 

文章来源: C# Reflection - Get PropertyInfo without a string [duplicate]