DataSourceSelectArguments Class

Reference

Definition

Namespace:: System.Web.UI

Assembly:: System.Web.dll

Important

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Provides a mechanism that data-bound controls use to request data-related operations from data source controls when data is retrieved. This class cannot be inherited.

public ref class DataSourceSelectArguments sealed

public sealed class DataSourceSelectArguments

type DataSourceSelectArguments = class

Public NotInheritable Class DataSourceSelectArguments

Inheritance: Object
DataSourceSelectArguments

Remarks

Data-bound controls use the DataSourceSelectArguments class to request that a data source control performs additional data-related operations on a result set, such as sorting the data or returning a specific subset of data. These data-related operations are enumerated by the DataSourceCapabilities enumeration. The following table indicates how the DataSourceSelectArguments class supports these data-related operations.

Capability	Related DataSourceSelectArguments properties
DataSourceCapabilities.Sort	SortExpression
DataSourceCapabilities.Page	StartRowIndex, MaximumRows
DataSourceCapabilities.RetrieveTotalRowCount	RetrieveTotalRowCount, TotalRowCount

Data-bound controls explicitly call the PerformSelect method to bind data, which calls the Select(DataSourceSelectArguments, DataSourceViewSelectCallback) method of the data source control they are associated with. In this way, the data-bound control retrieves data from the data source control on demand. Because the Select(DataSourceSelectArguments, DataSourceViewSelectCallback) method accepts a DataSourceSelectArguments parameter, the data-bound control is responsible for creating and managing a DataSourceSelectArguments object and passing it to the Select(DataSourceSelectArguments, DataSourceViewSelectCallback) method when it retrieves data from the data source control.

In some cases, data-bound controls might not need any additional data-related capabilities. In this case, data-bound controls pass an Empty arguments object to the Select(DataSourceSelectArguments, DataSourceViewSelectCallback) method.

For sorted result sets, data-bound controls check a data source view's CanSort property at run time, and add a DataSourceCapabilities.Sort capability using the AddSupportedCapabilities(DataSourceCapabilities) method. As a separate operation, the data-bound control can request a sorted result set from a data source control by setting the SortExpression property on the DataSourceSelectArguments object passed to the Select(DataSourceSelectArguments, DataSourceViewSelectCallback) method.

For paging scenarios, data-bound controls check a data source view's CanPage property at run time, and add a DataSourceCapabilities.Page capability using the AddSupportedCapabilities(DataSourceCapabilities) method. As a separate operation, the data-bound control can request a subset of data from a data source control for paging by setting the StartRowIndex and MaximumRows properties on the DataSourceSelectArguments object passed to the Select(DataSourceSelectArguments, DataSourceViewSelectCallback) method.

To retrieve a total row count for paging scenarios, data-bound controls check a data source view's CanRetrieveTotalRowCount property at run time, and add a DataSourceCapabilities.RetrieveTotalRowCount capability using the AddSupportedCapabilities(DataSourceCapabilities) method. As a separate operation, the data-bound control can request a total row count from a data source control for paging by setting the RetrieveTotalRowCount property on the DataSourceSelectArguments object passed to the Select(DataSourceSelectArguments, DataSourceViewSelectCallback) method. When the Select(DataSourceSelectArguments, DataSourceViewSelectCallback) method returns, the total row count is contained by the TotalRowCount property.

Important

If any of the DataSourceSelectArguments properties are set, but the currently bound data source control does not support the requested capability, an InvalidOperationException exception is thrown when the DataSourceSelectArguments.RaiseUnsupportedCapabilitiesError(DataSourceView) method is called.

Constructors

DataSourceSelectArguments()	Initializes a new default instance of the DataSourceSelectArguments class.
DataSourceSelectArguments(Int32, Int32)	Initializes a new instance of the DataSourceSelectArguments class with the specified starting position and number of rows to return for paging scenarios.
DataSourceSelectArguments(String, Int32, Int32)	Initializes a new instance of the DataSourceSelectArguments class with the specified sort expression, starting position, and number of rows to return for paging scenarios.
DataSourceSelectArguments(String)	Initializes a new instance of the DataSourceSelectArguments class with the specified sort expression.

Properties

Empty	Gets a DataSourceSelectArguments object with the sort expression set to Empty.
MaximumRows	Gets or sets a value that represents the maximum number of data rows that a data source control returns for a data retrieval operation.
RetrieveTotalRowCount	Gets or sets a value indicating whether a data source control should retrieve a count of all the data rows during a data retrieval operation.
SortExpression	Gets or sets an expression that the data source view uses to sort the data retrieved by the Select(DataSourceSelectArguments, DataSourceViewSelectCallback) method.
StartRowIndex	Gets or sets a value that represents the starting position the data source control should use when retrieving data rows during a data retrieval operation.
TotalRowCount	Gets or sets the number of rows retrieved during a data retrieval operation.

Methods

AddSupportedCapabilities(DataSourceCapabilities)	Adds one capability to the DataSourceSelectArguments instance, which is used to compare supported capabilities and requested capabilities.
Equals(Object)	Determines whether the specified DataSourceSelectArguments instance is equal to the current instance.
GetHashCode()	Returns the hash code for the DataSourceSelectArguments type.
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
RaiseUnsupportedCapabilitiesError(DataSourceView)	Compares the capabilities requested for an ExecuteSelect(DataSourceSelectArguments) operation against those that the specified data source view supports.
ToString()	Returns a string that represents the current object. (Inherited from Object)

Applies to

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