CODEWITHSUNDEEP
c#
Herrozerro
Herrozerro

Reputation: 1681

Referencing a field with a variable

I was wondering if it was possible to referance a class field via variable. like so:

int variable = 0;
while (variable > 3)
{
   class._fieldvariable = something;
   i++
}

where if I have fields: _field1, _field2, _field3 I can iterate through them all.

The main reason for doing this is I have an sql query that will append multiple records and I'd rather not have to do all the parameters multiple times but rather something like this:

while (i < 4)
}
   command.Parameters.AddWithValue("@Alpha1", _alphai01.ToString());
   i++
}

to let me set parameters 3 times with _alpha101, _alpha201 and _alpha301 are used for three different queries.

thanks!

Upvotes: 2

Views: 124

Answers (3)

Mahmoud Ibrahim
Mahmoud Ibrahim

Reputation: 1731

You could use reflection like this

if you have a class A 

 public class A
    {
        int field1, field2, field3;
    }

you could set these fields like this

 A obj = new A();
        for (int i = 1; i < 4; i++)
        {
            FieldInfo field = obj.GetType().GetField(String.Format("field{0}", i), BindingFlags.NonPublic | BindingFlags.Instance);
            if (null != field)
            {
                field.SetValue(obj, i);
            }

        }

Upvotes: 0

Daniel Daranas
Daniel Daranas

Reputation: 22624

Associate properties to the fields, all of them with get/set access.

If we're really talking about three fields, a more or less clean way to do so is by using a function GetField(int index) which would return the corresponding property. Then your code can be

class.GetField(i) = something;

An array is better in the more general case (for example, if the number of fields is expected to change).

I would prefer not to use reflection for such a simple purpose.

Upvotes: 1

dognose
dognose

Reputation: 20899

You can use invokeMember to call a certain setter of a property:

Object obj; //your instance;

obj.GetType().InvokeMember("Alpha1",
BindingFlags.Instance | BindingFlags.Public | BindingFlags.SetProperty,
Type.DefaultBinder, obj, "ValueForAlpha1");

that's equal to 

obj.Alpha1 = "ValueForAlpha1";

http://msdn.microsoft.com/en-US/library/vstudio/66btctbe.aspx

Upvotes: 0

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