How to 'select' object field when you only have a string with exact name as the object field

Question

Sorry if the title is not clear, it was hard to properly word this question.

I have an object named Stuff and MoreStuff.

public class Stuff()
{
    public string Field1;
    public string Field2;
}

public class MoreStuff()
{
    public string Field3;
    public string Field4;
}

I want to create something that adds a value to Field1 when the string fieldValue = 'Field1'

To make it more clear, something like this. But I want to have it generic for any object.:

string fieldValue = 'Field1'
Stuff thing = new Stuff();
checkField(fieldValue);
thing.fieldValue = 'checked';

string fieldValue = 'Field4'
MoreStuff moreThing = new MoreStuff();
checkField(fieldValue);
moreThing.fieldValue = 'checked';

Is this possible to do in C#? I can't find anything about it, also hard to search for a question like this.

Use reflection, but this sounds like it may be an [X-Y problem](http://xyproblem.info/). — DavidG, Oct 28 '15 at 14:05
You can use reflection to get the value of a field by name, however you can't just aribitrarily add fields to the object. You could do that with an ExpandoObject but not plain classes, at least not without IL weaving. — Ron Beyer, Oct 28 '15 at 14:07
Possible duplicate of [C# setting/getting the class properties by string name](http://stackoverflow.com/questions/10283206/c-sharp-setting-getting-the-class-properties-by-string-name) — DavidG, Oct 28 '15 at 14:07
Thanks, reflection was exactly what I was looking for. The adding of fields was just a bad example of me. — KHcc, Oct 28 '15 at 14:09

score 1 · Accepted Answer · answered Oct 28 '15 at 14:07

1

You can use reflection:

string fieldName = "Field1";
Stuff thing = new Stuff();

thing.GetType().GetField(fieldName).SetValue(thing, "checked");

answered Oct 28 '15 at 14:07

Jakub Lortz

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Thanks, I did not know about reflection. – KHcc Oct 28 '15 at 14:10

score 1 · Answer 2 · answered Oct 28 '15 at 14:11

Square test = new Square();
test.Field1 = "sdflsjf";
test.Field2 = "sdlfksj";
test.Field3 = "sldfjs";

foreach (PropertyInfo propertyInfo in test.GetType().GetProperties())
{
    if (propertyInfo.Name == "Field2")
        propertyInfo.SetValue(test, "checked");

}

This uses System.Reflection to do approximately what you're looking for by the sounds of it.

How to 'select' object field when you only have a string with exact name as the object field

2 Answers2