How to check if property setter is public

Question

给定一个 PropertyInfo 对象，如何检查该属性的 setter 是否是公共的？

Answer 1

Check what you get back from GetSetMethod :

MethodInfo setMethod = propInfo.GetSetMethod();

if (setMethod == null)
{
    // The setter doesn't exist or isn't public.
}

Or, to put a different spin on Richard's answer :

if (propInfo.CanWrite && propInfo.GetSetMethod(/*nonPublic*/ true).IsPublic)
{
    // The setter exists and is public.
}

Note that if all you want to do is set a property as long as it has a setter, you don't actually have to care whether the setter is public. You can just use it, public or private:

// This will give you the setter, whatever its accessibility,
// assuming it exists.
MethodInfo setter = propInfo.GetSetMethod(/*nonPublic*/ true);

if (setter != null)
{
    // Just be aware that you're kind of being sneaky here.
    setter.Invoke(target, new object[] { value });
}

Answer 2

.NET properties are really a wrapping shell around a get and set method.

You can use the GetSetMethod method on the PropertyInfo, returning the MethodInfo referring to the setter. You can do the same thing with GetGetMethod .

These methods will return null if the getter/setter is non-public.

The correct code here is:

bool IsPublic = propertyInfo.GetSetMethod() != null;

Answer 3

public class Program
{
    class Foo
    {
        public string Bar { get; private set; }
    }

    static void Main(string[] args)
    {
        var prop = typeof(Foo).GetProperty("Bar");
        if (prop != null)
        {
            // The property exists
            var setter = prop.GetSetMethod(true);
            if (setter != null)
            {
                // There's a setter
                Console.WriteLine(setter.IsPublic);
            }
        }
    }
}

Answer 4

You need to use the underling method to determine accessibility, using PropertyInfo.GetGetMethod() or PropertyInfo.GetSetMethod() .

// Get a PropertyInfo instance...
var info = typeof(string).GetProperty ("Length");

// Then use the get method or the set method to determine accessibility
var isPublic = (info.GetGetMethod(true) ?? info.GetSetMethod(true)).IsPublic;

Note, however, that the getter & setter may have different accessibilities, eg:

class Demo {
    public string Foo {/* public/* get; protected set; }
}

So you can't assume that the getter and the setter will have the same visibility.