How to get a property value based on the name

Question

is there a way to get the value of a property of a object based on its name?

For example if I have:

public class Car : Vehicle
{
   public string Make { get; set; }
}

and

var car = new Car { Make="Ford" };

I want to write a method where I can pass in the property name and it would return the property value. ie:

public string GetPropertyValue(string propertyName)
{
   return the value of the property;
}

Answer 1

return car.GetType().GetProperty(propertyName).GetValue(car, null);

Answer 2

You'd have to use reflection

public object GetPropertyValue(object car, string propertyName)
{
   return car.GetType().GetProperties()
      .Single(pi => pi.Name == propertyName)
      .GetValue(car, null);
}

If you want to be really fancy, you could make it an extension method:

public static object GetPropertyValue(this object car, string propertyName)
{
   return car.GetType().GetProperties()
      .Single(pi => pi.Name == propertyName)
      .GetValue(car, null);
}

And then:

string makeValue = (string)car.GetPropertyValue("Make");

Answer 3

You want Reflection

Type t = typeof(Car);
PropertyInfo prop = t.GetProperty("Make");
if(null != prop)
return prop.GetValue(this, null);

Answer 4

In addition other guys answer, its Easy to get property value of any object by use Extension method like:

public static class Helper
    {
        public static object GetPropertyValue(this object T, string PropName)
        {
            return T.GetType().GetProperty(PropName) == null ? null : T.GetType().GetProperty(PropName).GetValue(T, null);
        }

    }

Usage is:

Car foo = new Car();
var balbal = foo.GetPropertyValue("Make");

Answer 5

Expanding on Adam Rackis's answer - we can make the extension method generic simply like this:

public static TResult GetPropertyValue<TResult>(this object t, string propertyName)
{
    object val = t.GetType().GetProperties().Single(pi => pi.Name == propertyName).GetValue(t, null);
    return (TResult)val;
}

You can throw some error handling around that too if you like.

Answer 6

Simple sample (without write reflection hard code in the client)

class Customer
{
    public string CustomerName { get; set; }
    public string Address { get; set; }
    // approach here
    public string GetPropertyValue(string propertyName)
    {
        try
        {
            return this.GetType().GetProperty(propertyName).GetValue(this, null) as string;
        }
        catch { return null; }
    }
}
//use sample
static void Main(string[] args)
    {
        var customer = new Customer { CustomerName = "Harvey Triana", Address = "Something..." };
        Console.WriteLine(customer.GetPropertyValue("CustomerName"));
    }

Answer 7

为了避免反射，您可以使用您的属性名称作为键和函数在字典值部分中设置一个字典，这些函数从您请求的属性中返回相应的值。

Answer 8

2 Very short options, 1 with a default value if it fails:

public object GetPropertyValue_WithDefault(
    object _t,
    string _prop,
    object _default = null
)
{
    PropertyInfo pi = _t.GetType().GetProperty(_prop);
    return (pi == null
        ? _default
        : pi.GetValue(_t, null)
    );
}

public object GetPropertyValue(object _t, string _prop)
{
    //because of "?." will return null if property not found
    return _t.GetType().GetProperty(_prop)?.GetValue(_t, null); 
}