ASP.NET.in.a.Nutshell.Second.Edition [Electronic resources]

G. andrew Duthie; matthew Macdonald

نسخه متنی -صفحه : 873/ 481
نمايش فراداده

DesignTimeData

System.Web.UI.Design (system.design.dll)sealed class

This class provides shared helper methods that the design-time host (IDE) can use to generate "dummy" information for a sample rendering of a complex control. Typically, this class is used with table controls, as maintaining a database connection in design mode would be too resource-intensive, and the data source provider may not even be available. Using the CreateDummyDataTable( ) method, a default table is created that uses no information from the actual data source. This table could be used before a control's DataSource property is set.

Visual Studio .NET can also use a minimum amount of information to help present a design-time rendering of data tables. The GetDataFields( ) and GetDataMembers( ) methods retrieve a basic amount of information about the structure of the data source, which is then used when a dummy table is created with CreateSampleDataTable( ). The GetDesignTimeDataSource( ) method adds sample rows into the specified data table control.

public sealed class 

DesignTimeData { // Public Static Fields public static readonly EventHandler

DataBindingHandler ; // =System.EventHandler // Public Static Methods public static DataTable

CreateDummyDataTable ( ); public static DataTable

CreateSampleDataTable (System.Collections.IEnumerable

referenceData ); public static PropertyDescriptorCollection

GetDataFields (System.Collections.IEnumerable

dataSource ); public static IEnumerable

GetDataMember (System.ComponentModel.IListSource

dataSource , string

dataMember ); public static string[ ]

GetDataMembers (object

dataSource ); public static IEnumerable

GetDesignTimeDataSource (System.Data.DataTable

dataTable , int

minimumRows ); public static IEnumerable

GetSelectedDataSource (System.ComponentModel.IComponent

component , string

dataSource , string

dataMember ); public static object

GetSelectedDataSource (System.ComponentModel.IComponent

component , string

dataSource ); }