Why is my class method not visible when I implement an interface in my class?

I cannot see MyLoad.TreeLoader(), but why? I have implemented iloader to TreeViewLoad. I should be able to see TreeLoader().

namespace Rekursive
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            //treeView1.Nod开发者_C百科es.Add("Test");
            iloader MyLoad = new TreeViewLoad();
            MyLoad.loader("test", treeView1, 1);
        }
    }

    interface iloader
    {
        void loader(string nodeName, TreeView myTre, int id);
    }

    class TreeViewLoad : iloader
    {
       public void TreeLoader(TreeView tre)
        {
           // Here I want to call the loader
        }

        public void loader(string nodeName, TreeView myTre, int id)
        {
            myTre.Nodes.Add(nodeName + id.ToString());
            if (id < 10)
            {
                id++;
                loader(nodeName, myTre, id);
            }
        }
    }
}

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You are referring to the object through the interface, which means you only have access to the interface's methods and properties. The interface has a void loader method, TreeLoader belongs to the TreeViewLoad class.

TreeViewLoad myLoader = new TreeViewLoad();
// now you can access loader and TreeLoader.

---

you declare MyLoad variable as iloader interface so you can see only the interface methods here. To see TreeLoader method declare MyLoad of TreeViewLoad type

---

You declared the variable MyLoad to be of the interface type ILoader (I changed it from iloder to the more common convention for readability) and TreeLoader() is not a member of this interface and therefore you cannot access it. You can access it, if you cast the variable to TreeViewLoad.

ILoader myLoad = new TreeViewLoad();

((TreeViewLoad)myLoad).TreeLoader(...);

But you should rethink your design - you should usually not have to cast an interface to the concrete type and the fact that you have to indicates that something may be wrong.

---

This is my answer:

namespace Rekursive
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            iloader MyLoad = new TreeViewLoad();
            ((TreeViewLoad)MyLoad).TreeLoader(treeView1);
        }
    }

    interface iloader
    {
        void loader(string nodeName, TreeView myTre, int id);
    }

    class TreeViewLoad : iloader
    {
        public void TreeLoader(TreeView myTre)
        {
            loader("test", myTre, 1);
        }


        public void loader(string nodeName, TreeView myTre, int id)
        {

            myTre.Nodes.Add(nodeName + id.ToString());
            if (id