Part 1
Part 2
Part 3
Add System.Data.Services.Client reference from .NET tab
Add new web form to the project, name it Test
Set it as start up page
Add to the form
- drop down menu called departmentList
- text box called departmentName
- button called saveChanges
- button called deleteRecord
Open Text.aspx.cs file and add the following
using System.Data.Services.Client;
using Client.SchoolService;
declare some private variables and implement on page load procedure that will populate departmentList drop down. Remember - you can always watch video below to view all the steps.
Whole code so far looks like this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.Services.Client;
using Client.SchoolService;
namespace Client
{
public partial class Test : System.Web.UI.Page
{
private SchoolEntities context;
private Uri svcUri = new Uri("http://localhost:50433/SchoolService.svc");
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
loadDepartments();
}
}
private void loadDepartments()
{
context = new SchoolEntities(svcUri);
var departments = from d in context.Dpts
orderby d.DepartmentName
select new
{
Id = d.DepartmentId,
Name = d.DepartmentName
};
departmentList.DataTextField = "Name";
departmentList.DataValueField = "Id";
departmentList.DataSource = departments;
departmentList.DataBind();
departmentList.Items.Insert(0, new ListItem("Create new department", ""));
}
}
}
Run project and notice that drop down menu has been populated with some records from database
Now let's implement selected index changed of our departmentList - first ensure that AutoPostBack is set to true
Code looks like this:
protected void departmentList_SelectedIndexChanged(object sender, EventArgs e)
{
if (departmentList.SelectedValue == "")
{
departmentName.Text = "";
}
else
{
context = new SchoolEntities(svcUri);
int id = Convert.ToInt32(departmentList.SelectedValue);
List<Dpt> departments = (from d in context.Dpts
where d.DepartmentId == id
select d).ToList();
if (departments.Count() > 0)
{
Dpt dep = departments[0];
departmentName.Text = dep.DepartmentName;
}
else
{
departmentName.Text = "";
}
}
}
Run to see that now departmentName text box is populated with selected department. This is very simple example, both drop down menu and text box display same info - I just want to illustrate how to perform CRUD operations using WCF DataServices....
Next step is to implement Save function
Code looks like this:
protected void Changes_Click(object sender, EventArgs e)
{
context = new SchoolEntities(svcUri);
Dpt dep = new Dpt();
dep.DepartmentName = departmentName.Text;
// NEW RECORD - INSERT
if (departmentList.SelectedValue == "")
{
context.AddObject("Dpts", dep);
}
else
{
//EXISTING RECORD - UPDATE
dep.DepartmentId = Convert.ToInt32(departmentList.SelectedValue);
context.AttachTo("Dpts", dep);
context.UpdateObject(dep);
}
context.SaveChanges();
loadDepartments();
departmentList.Items.FindByValue(dep.DepartmentId.ToString()).Selected = true;
}
Again, test, to see if both insert and update functionality is working properly.
Last - delete
Code looks like this:
protected void deleteRecord_Click(object sender, EventArgs e)
{
if (departmentList.SelectedValue != "")
{
context = new SchoolEntities(svcUri);
Dpt dep = new Dpt();
dep.DepartmentId = Convert.ToInt32(departmentList.SelectedValue);
context.AttachTo("Dpts", dep);
context.DeleteObject(dep);
context.SaveChanges();
loadDepartments();
departmentName.Text = "";
}
}
That's it! Here is whole code from our web form
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.Services.Client;
using Client.SchoolService;
namespace Client
{
public partial class Test : System.Web.UI.Page
{
private SchoolEntities context;
private Uri svcUri = new Uri("http://localhost:50433/SchoolService.svc");
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
loadDepartments();
}
}
private void loadDepartments()
{
context = new SchoolEntities(svcUri);
var departments = from d in context.Dpts
orderby d.DepartmentName
select new
{
Id = d.DepartmentId,
Name = d.DepartmentName
};
departmentList.DataTextField = "Name";
departmentList.DataValueField = "Id";
departmentList.DataSource = departments;
departmentList.DataBind();
departmentList.Items.Insert(0, new ListItem("Create new department", ""));
}
protected void departmentList_SelectedIndexChanged(object sender, EventArgs e)
{
if (departmentList.SelectedValue == "")
{
departmentName.Text = "";
}
else
{
context = new SchoolEntities(svcUri);
int id = Convert.ToInt32(departmentList.SelectedValue);
List<Dpt> departments = (from d in context.Dpts
where d.DepartmentId == id
select d).ToList();
if (departments.Count() > 0)
{
Dpt dep = departments[0];
departmentName.Text = dep.DepartmentName;
}
else
{
departmentName.Text = "";
}
}
}
protected void Changes_Click(object sender, EventArgs e)
{
context = new SchoolEntities(svcUri);
Dpt dep = new Dpt();
dep.DepartmentName = departmentName.Text;
if (departmentList.SelectedValue == "")
{
context.AddObject("Dpts", dep);
}
else
{
dep.DepartmentId = Convert.ToInt32(departmentList.SelectedValue);
context.AttachTo("Dpts", dep);
context.UpdateObject(dep);
}
context.SaveChanges();
loadDepartments();
departmentList.Items.FindByValue(dep.DepartmentId.ToString()).Selected = true;
}
protected void deleteRecord_Click(object sender, EventArgs e)
{
if (departmentList.SelectedValue != "")
{
context = new SchoolEntities(svcUri);
Dpt dep = new Dpt();
dep.DepartmentId = Convert.ToInt32(departmentList.SelectedValue);
context.AttachTo("Dpts", dep);
context.DeleteObject(dep);
context.SaveChanges();
loadDepartments();
departmentName.Text = "";
}
}
}
}
