Just enough to test a Windows UI

Here's just enough code to test a Windows Form. Put this in a Class Library project called Tests which references the DLL or EXE with the form in. The Tests project will need to reference System.Windows.Forms.

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using Dunwoody;
using NUnit.Framework;

namespace Tests
{
    [TestFixture]
    public class UITests
    {
        Form1 m_f;
        [SetUp]
        public void SetUp()
        {
            m_f = new Form1();
            m_f.Show();
        }
        [TearDown]
        public void TearDown()
        {
            m_f.Dispose();
            m_f = null;
        }

        [Test]
        public void RequiredWidgets()
        {
            Assert.AreEqual( "", HasWidgets(new string[] { 
                "button1", "textbox1" 
            }));
        }

        private string HasWidgets(string[] ctrlnames )
        {
            StringBuilder result = new StringBuilder();
            foreach (string ctrlname in ctrlnames)
            {
                if (GetControl(ctrlname) == null)
                    result.Append(ctrlname + " ");
            }
            return result.ToString().Trim();
        }

        [Test]
        public void HasButton()
        {
            Button b = GetButton( "button1" );
            Assert.IsNotNull(b);
        }
        [Test]
        public void NoSuchButton()
        {
            Assert.IsNull(GetButton("x"));
        }
        [Test]
        public void TextboxNotButton()
        {
            Assert.IsNotNull(GetControl("textbox1"));
            Assert.IsNull(GetButton("textbox1"));
        }
        [Test]
        public void HasTextbox()
        {
            Assert.IsNotNull(GetTextbox("textbox1"));
        }
        [Test]
        public void SetTextbox()
        {
            string test = "Test";
            GetTextbox("textbox1").Text = test;
            Assert.AreEqual(test, GetTextbox("textbox1").Text);
        }
        [Test]
        public void ButtonClick()
        {
            string test = "Test";
            string str = GetTextbox("textbox1").Text;
            GetTextbox("textbox1").Text = test;
            GetButton("button1").PerformClick();
            Assert.AreEqual("[" + test + "]", GetTextbox("textbox1").Text);
        }

        private TextBox GetTextbox(string ctrlname)
        {
            Control ctrl = GetControl(ctrlname);
            if (ctrl != null)
                return ctrl as TextBox;
            return null;
        }

        private Button GetButton(string ctrlname )
        {
            Control ctrl = GetControl(ctrlname);
            if (ctrl != null)
                return ctrl as Button;
            return null;
        }

        private Control GetControl(string ctrlname)
        {
            foreach (Control ctrl in m_f.Controls)
                if (String.Compare(ctrlname.Trim(), ctrl.Name, true) == 0)
                    return ctrl;
            return null;
        }
    }
}