Question

I’ve created a simple user control in Windows Forms that consists of a button and a textbox. The click event of the button resizes the text box and adds some text. I don’t know if this part of the code is relevant, but I’ll include it anyway.

namespace testUserControl
{
    public partial class UserControl1 : UserControl
    {
        public UserControl1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            textBox1.Width = 200;
            textBox1.Height = 200;
            textBox1.Text = "this text was added by the button";
        }
    }
}

In the project where I’m trying to include this user control in several places, I have a button with a click event that adds a tab page. I want the tab page to include this custom user control. However, when I use this code, I get an error stating: 'testUserControl is a namespace but used like a type':

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

        private void button1_Click(object sender, EventArgs e)
        {
            TabPage item = new TabPage("header text");
            tabControlCitations.Controls.Add(item);
            testUserControl u = new testUserControl(); //<!-- error occurs here
            item.Controls.Add(u);
        }
    }
}

How do I include and use this custom user control in my project?

Answer 1

As the error clearly states, testUserControl is a namespace.

The type is UserControl1.
You will also need a using statement to import the namespace.