Add Two Numbers (Visual F# Windows Forms Application)

I’d been desperately combing the net for a while now looking for some tutorials relating to simple computations in Visual F# Windows Forms Application unfortunately I got no fluke finding some so I decided to make one. Today we will be making a simple application that adds two numbers and I hope that this will give you a head start in building advanced application using F# Windows Forms.
To create an application that adds two numbers, follow these simple steps:

1. Click Start>All Programs>Microsoft Visual Studio 2008>Microsoft Visual Studio 2008.

2. Click File>New>Project>Select Visual F# in the project types>Select F# application in the Visual Studio installed templates category.

3. Click the Project menu>Add reference>Click the .Net tab>Locate then double-click System.Windows.Forms.
Do step number 3 again and this time,select System.Drawing

4. Enter the following code after the line “// Learn more about F# at “:

// Learn more about F# at
//uses the F# standard library
open System
//specifies the location of the Drawing classes
open System.Drawing
//specifies the namespace memory location of the form class
open System.Windows.Forms
//creates a new form
let addform=new Form(Text="Add Numbers", Size=new System.Drawing.Size(300, 200),StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)
//creates a label
let n1label=new Label(Text="First number:",Top=20,Left=5,AutoSize=true)
let firsttextbox=new TextBox(Location=new System.Drawing.Point(80, 20))
//creates another label and change its text to “Second number:”
let n2label=new Label(Text="Second number:", Location=new System.Drawing.Point(0,50),AutoSize=true)
let secondtextbox=new TextBox(Location=new System.Drawing.Point(100,50))
//creates another label and change its text to sum
let n3label=new Label(Text="Sum:", Location=new System.Drawing.Point(0, 90),AutoSize=true)
//creates a label that will display the result of the computation
let anslabel=new Label(Location=new System.Drawing.Point(80, 90))
//make our buttons
let addbutton=new Button(Text="Add", Location=new System.Drawing.Point(100, 130))
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 130))
//add the controls into the form

//when the add button is clicked
addbutton.Click.Add(fun addfunction ->
//convert the textbox values to unsigned int
let firstnum=Convert.ToUInt32(firsttextbox.Text)
let secondnum=Convert.ToUInt32(secondtextbox.Text)
let sumval=firstnum + secondnum
//display the sum in the anslabel
 //when the exit button is clicked, close the form            
exitbutton.Click.Add(fun exit -> addform.Close())  

6. Press Ctrl+F5 or click the run icon to execute your application. You should now see something similar to the screenshot below:

7. That's all. Enjoy programming!