use parameter to get class's property

Question

0.00/5 (No votes)

See more:

Hi,

I would like to have a function which should be something like that:

public string GetClassProperty(string propertyName)
{
   MyClass entity = new MyClass();
   return entity.[propertyName];
}

public MyClass
{
   public string Name { get; set; }
   public string Desc { get; set; }
}

meaning: I pass the function the property name, and the function will return my class's related property

Any ideas?

Posted 6-Jun-12 2:05am

DanaH85

Add a Solution

2 solutions

Solution 2

To get the property of a class with the syntax [ ] Indexer explained here http://msdn.microsoft.com/en-us/library/6x16t2tx.aspx[^] can be used.

Since, a property of the class is required to be returned the return type can be PropertyInfo class explained here http://msdn.microsoft.com/en-us/library/system.reflection.propertyinfo.aspx[^]

The GetValue and SetValue methods of PropertyInfo requires the object whose property value is required. In the present case since the property is of the class which returned it, it is redundant to again pass the instance of the class to get the value or set the value of the property.

Hence, a class InstancePropertyInfo is created as shown below:

C#

void Main()
{
    MyClass myclass = new MyClass();
    myclass.Name="MyName";
    InstancePropertyInfo pinfo = myclass["Name"];
    Console.WriteLine (pinfo.GetValue());
    
    myclass["Desc"].SetValue("Description---");
    Console.WriteLine (myclass["Desc"].GetValue());
    
    //Output
    //MyName
    //Description---
}

public class MyClass {
    public InstancePropertyInfo this[string propertyName] {
    	get {
    	return 
    		new InstancePropertyInfo (this, this.GetType().GetProperty(propertyName, 
    		BindingFlags.Instance | BindingFlags.Public));
    	}
    }
    public string Name { get; set; }
    public string Desc { get; set; }
}
public class InstancePropertyInfo {
    PropertyInfo propertyInfo;
    object target;
    
    public InstancePropertyInfo (object target, PropertyInfo propertyInfo) {
    	this.target = target;
    	this.propertyInfo=propertyInfo;
    }
    
    public object GetValue () {
    	return propertyInfo.GetValue(target, null);
    }
    public void SetValue(object value) {
    	propertyInfo.SetValue(target,value,null);
    }
}

Posted 6-Jun-12 7:17am

VJ Reddy

Comments

Manas Bhardwaj 6-Jun-12 16:05pm

Nicely explained +5

VJ Reddy 6-Jun-12 19:36pm

Thank you, Manas :)

Maciej Los 6-Jun-12 17:47pm

Interesting, my 5!

VJ Reddy 6-Jun-12 19:37pm

Thank you, losmac :)

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Manas Bhardwaj · Accepted Answer · 2012-06-06T02:14:00

Check out MSDN documentation http://msdn.microsoft.com/en-us/library/kz0a8sxy.aspx[^]

Something like this:

C#

class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine(GetClassProperty("A"));
            Console.WriteLine(GetClassProperty("B"));
            Console.ReadLine();
        }

       public static string GetClassProperty(string propertyName)
        {
           MyClass myClass = new MyClass();
           Type type = myClass.GetType();
           return type.GetProperty(propertyName).GetValue(myClass, null).ToString();
        }
    }

    public class MyClass
    {
        public int A
        {
            get
            {
                return 100;
            }
        }

        public int B
        {
            get
            {
                return 101;
            }
        } 
    }