Creating DataBase: We create a DataBase
for getting records into a ComboBox. Here, in this example, the DataBase name is
student_record, table name is student and Columns are Roll_No and Name. I have written code below for creating this database.
create database student_record
use student_record
create table student
(
Roll_No int primary key,
Name varchar(20) )
insert into
student values(1,'Alok
Pandey')
insert into
student values(2,'Satish
Kumar')
insert into student
values(3,'Amitabh
Pandey')
insert into student
values(4,'Pramod
Sharma')
insert into student
values(5,'Durgesh
Pandey')
After creating the DataBase and
table we start to a develop F# application for DataBinding with a ComboBox. We
follow the following steps for this.
Step 1: Create an F# application.
Step 2: We go to Solution Explorer and
Right Click on References.
Step 3: Now, Click on Add References. Then
a pop-up window with caption Add Reference will open as in the below figure.
Step 4: After Step-3, Click at .Net on Add Reference
window and select System.Windows.Forms and System.Data with
holding down Ctrl key and Click on Ok.
Step 5: Write the below F# code in the
Program.fs file.
open
System
open
System.Windows.Forms
open
System.Data.SqlClient
open System.Data
// cteating connection string
let constring =
@"Data Source=Server_Name;Initial
Catalog=student_record;Integrated Security=True"
//Creating SqlDataAdapter
let da =
new SqlDataAdapter("select
* from student",constring)
//creating DataSet
let ds =
new DataSet()
//filling the DataSet
da.Fill(ds)|>ignore
//creating Form
let form =
new Form()
//creating ComboBox
let cmb =
new ComboBox()
//Adding Control
form.Controls.Add(cmb)
//Binding ComboBox
cmb.DataSource <- ds.Tables.[0]
cmb.DisplayMember <- "Roll_No"//
For displaying column values
Application.Run(form)
Now we run this
application.
Output:
We Click on ComboBox. We look that it show all the Roll_No.
In Student table, There are
two columns. Suppose we want to select Roll_No of students into ComboBox and
display student name in a Label or TextBox whose Roll_No is selected in the ComboBox.
For this, We will Write code on SelectedValueChanged event of ComboBox. In this
example, I am displaying record in Label. Write the following code.
open System
open
System.Windows.Forms
open
System.Data.SqlClient
open System.Data
// cteating connection string
let constring =
@"Data Source=Server_Name;Initial
Catalog=student_record;Integrated Security=True"
//creating SqlDataAdapter
let da =
new SqlDataAdapter("select
* from student",constring)
//creating DataSet
let ds =
new DataSet()
//filling the DataSet
da.Fill(ds)|>ignore
//creating Form
let form =
new Form()
//creating ComboBox
let cmb =
new ComboBox()
let lbl =
new Label(Top = 50)
//Adding Control
form.Controls.Add(cmb)
form.Controls.Add(lbl)
//Binding ComboBox
cmb.DataSource <- ds.Tables.[0]
cmb.DisplayMember <- "Roll_No"//
For displaying column values
cmb.ValueMember <- "Name"//
for containing value
cmb.DataSource <- ds.Tables.[0]
cmb.SelectedValueChanged.Add(fun a
-> lbl.Text <- cmb.SelectedValue.ToString() )
Application.Run(form)
Now we run this
application.
Output:
