C# – Which control performs the type conversion:GridView or data source control

ado.netasp.netcnet

Say we data bind GridView to an ObjectDataSource control and then perform a query.

A) I realize displayed GridView fields are of type String, but does GridView also know of what type the underlying data source values are ( for particular GridView column )?

* Thus, if data source will populate GridView with bunch of integers, then these integers will have to be converted to strings, before they can be displayed in GridView. Which control will perform the conversion, GridView or ObjectDataSource/SqlDataSource control?

B) Regardless of whether GridView or ObjectDataSource performs a conversion, how is that conversion performed? Simply by calling ToString() on an object?

thanx

Best Answer

The formatting (which includes the conversion) is done by the GridView. You can see that by looking at the per-column DataFormatString property. This uses the general .NET composite formatting, see for example string.Format() or Console.Writeline(). It defaults to ToString(). But DataFormatString will accept dd-mm-yyyy for a DateTime column.

Related Solutions

.net – Which method performs better: .Any() vs .Count() > 0

If you are starting with something that has a .Length or .Count (such as ICollection<T>, IList<T>, List<T>, etc) - then this will be the fastest option, since it doesn't need to go through the GetEnumerator()/MoveNext()/Dispose() sequence required by Any() to check for a non-empty IEnumerable<T> sequence.

For just IEnumerable<T>, then Any() will generally be quicker, as it only has to look at one iteration. However, note that the LINQ-to-Objects implementation of Count() does check for ICollection<T> (using .Count as an optimisation) - so if your underlying data-source is directly a list/collection, there won't be a huge difference. Don't ask me why it doesn't use the non-generic ICollection...

Of course, if you have used LINQ to filter it etc (Where etc), you will have an iterator-block based sequence, and so this ICollection<T> optimisation is useless.

In general with IEnumerable<T> : stick with Any() ;-p

C# – How to get the type of T from a member of a generic class or method

If I understand correctly, your list has the same type parameter as the container class itself. If this is the case, then:

Type typeParameterType = typeof(T);

If you are in the lucky situation of having object as a type parameter, see Marc's answer.

Best Answer

Related Solutions

.net – Which method performs better: .Any() vs .Count() > 0

C# – How to get the type of T from a member of a generic class or method

Related Topic