How to call UIApplication of my current Document

[Ali.sadeghi.h1994]

Hi everyone. I defined a  command class that considers Execute method and some other defined methods by me to call in Execute method or other classes. I tend to call my method with name of " LoadFamily" and its first parameter is UIApplication of my command class. The point is that I don't know how should I call that parameter when I'm in a form button.(In other word, how should I call the UIApplication of my command class somewhere out of command class?) .see the codes below.

// my button in my Form
private void btn1_Click(object sender, EventArgs e)
        {
            AddFamilies addFamilies1 = new AddFamilies();
            addFamilies1.LoadFamily(--!!???????!!--,@"E:\","HazardSign");
        }

 below is my method in command class

//My command class
public class AddFamilies : IExternalCommand
    {
        public Document MyDoc;
        public UIApplication MyApplication;

        public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
        {
            UIApplication uiApp = commandData.Application;
            Document doc = uiApp.ActiveUIDocument.Document;

            using (System.Windows.Forms.Form form = new LoadFamilies(doc))
            {
                if (form.ShowDialog() == DialogResult.OK)
                {
                    return Result.Succeeded;
                }
                else
                {
                    return Result.Cancelled;
                }
            }
            return Result.Succeeded;
        }

         public void LoadFamily(UIApplication uiApplication, string FamiliesAddress, string FamilyName)
        {
            Document document = uiApplication.ActiveUIDocument.Document;
            Application application = uiApplication.Application;

            ...codes...
        }
    }

[jeremy_tammik · Accepted solution]

Make the UIApplication instance a member variable of your form class. Store the value you receive in the constructor in the member variable. Use it in the button click handler method.

[moturi.magati.george · Accepted solution]

Hi @Ali.sadeghi.h1994,

Here is a tutorial that explains step by step on creating WPF forms and calling methods outside your command class. https://www.youtube.com/watch?v=vHsqxRAqQOg

[Ali.sadeghi.h1994]

@moturi.magati.george  thanks for your help. That was a great tutorial in this case and helped me a lot.

[Ali.sadeghi.h1994]

Thanks @jeremy_tammik  .

That worked. Thank you for your guidance. You are great as always.