How to add properties at runtime dynamically to the object c#?

Question

Below is the code snippet of what i am trying to do.

dynamic model = new ExpandoObject();
        foreach (Control control in ConfigData.ActiveForm.Controls)
        {
            string controlType = control.GetType().ToString();
            if (controlType == "System.Windows.Forms.TextBox")
            {
                TextBox txtBox = (TextBox)control;
                if (string.IsNullOrEmpty(txtBox.Text))
                {
                    MessageBox.Show(txtBox.Name + " Can not be empty");
                    return;
                }
                model[txtBox.Name] = txtBox.Text; // this gives error
            }
          

        }

here i want to create a property with name of the value came from txtBox.name

for example if value of textBox.name="mobileNo" i want to add a property with name mobileNo to model. how to do that?

You need to cast it(model) first to `IDictionary` as `ExpandoObject` implements it explicity — Selvin, Jun 25 '20 at 10:12
*dynamic obj= new ExpandoObject(); obj.NewProp= 1;* @viveknuna and how you willl use `txtBox.Name` as `NewProp` ? — Selvin, Jun 25 '20 at 10:17
@Selvin I gave reference to the OP, he/she can use accordingly — Vivek Nuna, Jun 25 '20 at 10:22
why even use an `ExpandoObject` at all? Why not have a static class-structure? In my experience 9 of 10 use-cases for `dynamic` are crippled attemps and you´re better using a fix data-structure, as you usually know what kind of data you have and which operarations this data enables. — MakePeaceGreatAgain, Jun 25 '20 at 10:23
@viveknuna what reference? they using `txtBox.Name` as property name which is not known at compile time `obj.NewProp` is using compile time const as property name — Selvin, Jun 25 '20 at 10:37
Does this answer your question? [Why can't I index into an ExpandoObject?](https://stackoverflow.com/questions/26778554/why-cant-i-index-into-an-expandoobject) — Pavel Anikhouski, Jun 25 '20 at 11:03

score 2 · Accepted Answer · answered Jun 25 '20 at 10:22

dynamic expando = new ExpandoObject();

// Add properties dynamically to expando
AddProperty(expando, "Language", "English");

public static void AddProperty(ExpandoObject expando, string propertyName, object propertyValue)
{
    // ExpandoObject supports IDictionary so we can extend it like this
    var expandoDict = expando as IDictionary<string, object>;
    if (expandoDict.ContainsKey(propertyName))
        expandoDict[propertyName] = propertyValue;
    else
        expandoDict.Add(propertyName, propertyValue);
}

Thanks to Jay Hilyard and Stephen Teilhet

source: https://www.oreilly.com/content/building-c-objects-dynamically/

How to add properties at runtime dynamically to the object c#?

1 Answers1