SharePoint 2010 - Connected Web Parts

In this article we can explore Connected Web Parts which is an advanced SharePoint Web Part feature. The connected web parts denote communication between 2 web parts.



The connected web part resolves the following requirements:

• Master Web Part and Slave web part data exchange
• Data Selection and Data Display web part communication

Summary of the application is:

• There are 2 web parts
• Web Part 1 has a drop down list for selecting Car
• Web Part 2 displays the car picture based on selection

Steps Involved

Following are the steps involved in creating connected web parts:

1. Create Project
2. Create Communication Interface
3. Create Web Part 1 (Provider) implementing Interface
4. Create Web Part 2 (Consumer)
5. Build and Deploy

Create Project

We can experiment with a Car showcase application where there are 2 web parts.

• The first web part allows selecting a Car from the drop down list.
• The second web part displays the image of the car.

to begin, create a new Web Part project in Visual Studio.



Remove the default VisualWebPart1 web part. We will be adding our own web parts.

Create Interface

For communication between the 2 web parts we need to create an interface. Please create the following interface, which returns the selected Car name:

public interface ICar
{
string Car { get; }
}

Create Provider Web Part implementing Interface

Now you can create a new web part named CarSelectionWebPart. Expand the webpart item and in the User Control (CarSelectionWebPartUserControl.ascx) class file:

1. Add a drop down list control
2. Place the following code

public partial class CarSelectionWebPartUserControl : UserControl
{
protected void Page_Load(object sender, EventArgs e)

{

if (!this.IsPostBack)
{
DropDownList1.Items.Clear();
DropDownList1.Items.Add("Camry");
DropDownList1.Items.Add("Figo");
DropDownList1.Items.Add("Diablo");
}
}

// Property to expose selected car outside
public string Car
{
get;
set;
}

// Set the Car property
protected void Button1_Click(object sender, EventArgs e)
{
if (DropDownList1.SelectedItem != null)
Car = DropDownList1.SelectedItem.Text;
}
}

In the CarSelectionWebPart.cs (web part class file) add the following code:

// Property to return the selected Car

public string Car

{

get

{