ASP.NET 4 Unleased - p 39

Overview of Data Access FIGURE Using the ControlParameter object. LISTING Show Control Parameter | 354 CHAPTER 8 Overview of Data Access FIGURE Using the ControlParameter object. LISTING @ Page Language C DOCTYPE html PUBLIC - W3C DTD XHTML EN http TR xhtml11 DTD html xmlns http 1999 xhtml head id Head1 runat server title Show Control Parameter title head body form id form1 runat server div asp DropDownList id ddlMovieCategory DataSourceID srcMovieCategories DataTextField Name DataValueField Id Runat server asp Button id btnSelect From the Library of Wow eBook Using DataSource Controls 355 Text Select ToolTip Select Movie Runat server hr asp GridView id grdMovies DataSourceID srcMovies Runat server asp SqlDataSource id srcMovieCategories ConnectionString Server . SQLExpress Trusted_Connection True AttachDbFileName DataDirectory User Instance True SelectCommand SELECT Id Name FROM MovieCategories Runat server asp SqlDataSource id srcMovies ConnectionString Data Source . SQLExpress AttachDbFilename DataDirectory Integrated Security True User Instance True SelectCommand SELECT Title Director FROM Movies WHERE CategoryId @Id Runat server SelectParameters asp ControlParameter Name Id Type int32 ControlID ddlMovieCategory SelectParameters asp SqlDataSource 8 div form body html The SqlDataSource control includes a ControlParameter object. The ControlParameter represents the selected item in the DropDownList control. The value of the ControlParameter is used in the SqlDataSource control s SelectCommand to select movies that match the category selected in the DropDownList control. From the Library of Wow eBook 356 CHAPTER 8 Overview of Data Access Using Programmatic DataBinding When you bind a DataBound control to a DataSource control you can take advantage of declarative databinding. When you use declarative databinding Framework handles all the messy details of deciding when to retrieve the data items represented by a DataSource control. In certain situations .