How to: Modify a Silverlight Screen by Using Code

 

For the latest documentation on Visual Studio 2017, see Visual Studio 2017 Documentation.

Visual Studio LightSwitch enables you to accomplish many screen-related design tasks by using designers and tool windows. However, there are certain tasks that you might want to accomplish by using code. This topic shows you how to accomplish a set of common screen-related design tasks by using the screen object model. For more information about where you can write code in your application, see any of the following topics:

• How to: Handle Data Events

• How to: Handle Silverlight Screen Events

• How to: Handle Query Events

Common Tasks

The following list describes some common data-related tasks that you accomplish by using the screen object model.

• Making controls hidden, read-only, or disabled

Making Controls Hidden, Read-Only, or Disabled

You can hide or show controls on a screen by using code. You can also specify whether controls are read-only or disabled.

The following example hides a company name in a data grid if the company name is Great Lakes Food Market. This example also makes the control read-only so that viewers cannot modify the company name by typing text into the control.

        private void FindControlInList()
        {
            int index = 0;

            foreach (Customer cust in this.Customers)
            {
                if (cust.CompanyName == "Great Lakes Food Market")
                {
                    this.FindControlInCollection("CompanyName",
                    this.Customers.ElementAt(index)).IsVisible = false;
                    this.FindControlInCollection("CompanyName",
                    this.Customers.ElementAt(index)).IsReadOnly = true;
                }

                index++;
            }

        }

        Private Sub FindControlInList()
            Dim index As Integer = 0

            For Each cust As Customer In Customers

                If cust.CompanyName = "Great Lakes Food Market" Then
                    With FindControlInCollection("CompanyName", Customers(index))
                        .IsVisible = False
                        .IsReadOnly = True
                    End With

                End If
                index = index + 1
            Next
        End Sub

The following example hides the company name in a details view on the screen if the company name of the selected item is Great Lakes Food Market. This example also disables the Delete button so that users cannot delete a customer who works for Great Lakes Food Market.

        partial void Customers_SelectionChanged()
        {
            this.FindControl("Customers_DeleteSelected").IsEnabled = true;

            if (this.Customers.SelectedItem.CompanyName == "Great Lakes Food Market")
            {
                this.FindControl("CompanyName1").IsVisible = false;
                this.FindControl("Customers_DeleteSelected").IsEnabled = false;
            }
        }

        Private Sub Customers_SelectionChanged()
            FindControl("Customers_DeleteSelected").IsEnabled = True

            If Me.Customers.SelectedItem.CompanyName = "Great Lakes Food Market" Then

                FindControl("CompanyName1").IsVisible = False
                FindControl("Customers_DeleteSelected").IsEnabled = False

            End If

        End Sub

See Also

Screens: The User Interface of Your LightSwitch Application
How to: Handle Silverlight Screen Events
Performing Data-Related Tasks by Using Code