Testing Web User Controls

To test a Web user control, you need a Web application. Typically, you use a Web application that's part of the same solution as the Web user control itself, as we did in the WebUserControls example in the In Depth section of this chapter.

To add a Web user control to a form in the test Web application, you can drag the ASCX file that supports the Web user control onto the form. For example, dragging the file WebUserControl1.ascx file creates the Web user control WebUserControl11. You should also declare that control in the Web form you're using it in, like this:

Public Class WebForm1
    Inherits System.Web.UI.Page
    Protected WithEvents Button1 As System.Web.UI.WebControls.Button
    Protected WithEvents TextBox1 As System.Web.UI.WebControls.TextBox
    Protected WithEvents WebUserControl11 As WebUserControl1
        ⋮

In the WebUserControls example discussed in the In Depth section of this chapter, we tested the Web user control's DisplayColor property, SetText method, and TextModified event in the test application. Here's how that was done in that example's WebForm1.aspx.vb file:

Public Class WebForm1
    Inherits System.Web.UI.Page
    Protected WithEvents Button1 As System.Web.UI.WebControls.Button
    Protected WithEvents TextBox1 As System.Web.UI.WebControls.TextBox
    Protected WithEvents WebUserControl11 As WebUserControl1

' Web Form Designer Generated Code...

    Private Sub Page_Load(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Load
        WebUserControl11.DisplayColor = Color.Aqua
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles Button1.Click
        WebUserControl11.SetText("Hello!")
    End Sub

    Private Sub WebUserControl11_TextModified(ByVal NewText As String) _
        Handles WebUserControl11.TextModified
        TextBox1.Text = "New text: " & NewText
    End Sub
End Class

For more on this example and on how we set up the test Web application, see the In Depth section of this chapter.