Build Your Own ASP.NET 2.0 Web Site Using C# & VB, Second Edition

else

{

gridSortDirection = SortDirection.Ascending;

}

}

else

{

gridSortDirection = SortDirection.Ascending;

}

Finally, we save the new sort expression to the gridSortExpression property,

whose value will be retained in case the user keeps working (and changing sort

modes) on the page:

Visual Basic File: Departments.aspx.vb (excerpt)

' Save the new sort expression

gridSortExpression = sortExpression

' Rebind the grid to its data source

BindGrid()

C# File: Departments.aspx.cs (excerpt)

// Save the new sort expression

gridSortExpression = sortExpression;

// Rebind the grid to its data source

BindGrid();

After we store the sort expression, we rebind the grid to its data source so that

the expression will reflect the changes we’ve made to the gridSortExpression

and gridSortDirection properties.

Filtering Data

Although we’re not using it in the Dorknozzle project, it’s interesting to note

that the DataView control can filter data. Normally you’d have to apply WHERE

clauses to filter the data before it reaches your application, but in certain cases

you may prefer to filter data on the client.

Imagine that you wanted to display employees or departments whose names

started with a certain letter. You could retrieve the complete list of employees or

departments from the database using a single request, then let the user filter the

list locally.

520

Chapter 12: Advanced Data Access