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DataParameter Class

Represents a data parameter that is derived from a data source command, or that is passed with a command to a data source.

Inheritance Hierarchy

System.Object
  Microsoft.VisualStudio.Data.Framework.DataParameter
    Microsoft.VisualStudio.Data.Framework.AdoDotNet.AdoDotNetParameter

Namespace:  Microsoft.VisualStudio.Data.Framework
Assembly:  Microsoft.VisualStudio.Data.Framework (in Microsoft.VisualStudio.Data.Framework.dll)

Syntax

'Declaration
Public MustInherit Class DataParameter _
    Implements IVsDataParameter, IVsDataParameterDescriptor
public abstract class DataParameter : IVsDataParameter, 
    IVsDataParameterDescriptor
public ref class DataParameter abstract : IVsDataParameter, 
    IVsDataParameterDescriptor
[<AbstractClass>]
type DataParameter =  
    class 
        interface IVsDataParameter 
        interface IVsDataParameterDescriptor 
    end
public abstract class DataParameter implements IVsDataParameter, IVsDataParameterDescriptor

The DataParameter type exposes the following members.

Constructors

  Name Description
Protected method DataParameter() Initializes a new instance of the DataParameter class.
Protected method DataParameter(Boolean) Initializes a new instance of the DataParameter class, specifying whether the instance was derived using the DeriveParameters method.

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Properties

  Name Description
Protected property DefaultSize Gets an integer value specifying the default size for the current parameter type.
Public property Descriptor Gets information that describes the data parameter.
Public property Direction Gets or sets a DataParameterDirection object specifying the direction of the parameter.
Protected property HasDescriptor Gets a value indicating whether the data parameter exposes its IVsDataParameterDescriptor implementation through the Descriptor property.
Public property IsDerived Gets a Boolean value that indicates whether the current parameter was derived from the data source.
Protected property IsFixedSize Gets a Boolean value indicating whether the size for the current parameter type is fixed.
Public property IsNullable Gets a Boolean value indicating whether the current parameter can have a null value provided that it is derived.
Public property IsOptional Gets a Boolean value indicating whether the current parameter is optional, provided that it is derived.
Public property Name Gets or sets the string literal name of the current parameter.
Public property Size Gets or sets an integer value specifying the size of the parameter.
Public property Type Gets or sets the data source–specific type of the parameter.
Public property Value Gets or sets the value of the parameter.

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Methods

  Name Description
Public method Equals Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected method Finalize Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Protected method GetDirectionCore Retrieves the parameter direction.
Public method GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Protected method GetIsNullableCore Retrieves a Boolean value indicating whether the current parameter can be nulla null reference (Nothing in Visual Basic).
Protected method GetIsOptionalCore Retrieves a Boolean value indicating whether the parameter is optional.
Protected method GetNameCore Retrieves the name of the parameter.
Protected method GetSizeCore Retrieves an integer value specifying the size of the parameter.
Public method GetType Gets the Type of the current instance. (Inherited from Object.)
Protected method GetTypeCore Retrieves the data source–specific type of the parameter.
Protected method GetTypeFrom Infers the data source–specific parameter type from a parameter value.
Protected method GetValueCore Retrieves the value of a specified parameter.
Protected method IsSupportedDirection Retrieves a Boolean value indicating whether the specified parameter direction is supported.
Protected method IsValidType Retrieves a Boolean value indicating whether the specified data source–specific type is a valid type.
Protected method MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Protected method OnDirectionChanged Called when the Direction property is changed to signal a change in the parameter direction.
Protected method OnDirectionChanging Called when the Direction property is about to change.
Protected method OnNameChanged Called when the Name property has changed.
Protected method OnNameChanging Called when the Name property is about to change.
Protected method OnSizeChanged Called when the Size property has changed.
Protected method OnSizeChanging Called when the Size property is about to change.
Protected method OnTypeChanged Called when the Type property has changed.
Protected method OnTypeChanging Called when the Type property is about to change.
Protected method OnValueChanged Called when the Value property has changed.
Protected method OnValueChanging Called when the Value property is about to change.
Public method Parse Disassembles a parameter value in a string format and converts the value to the correct type.
Protected method SetDirectionCore Sets the direction of the parameter by using the DataParameterDirection enumeration.
Protected method SetNameCore Sets the name of the parameter.
Protected method SetSizeCore Sets an integer value specifying the size of the current parameter.
Protected method SetTypeCore Sets the data type of the current parameter.
Protected method SetValueCore Sets the value of the parameter.
Public method ToString Retrieves a string representation of the value of the current parameter. (Overrides Object.ToString().)
Protected method TryConvertValue Attempts to convert the specified value to the specified type.

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Fields

  Name Description
Public fieldStatic member NullSize A public size constant holding the value of zero.

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Remarks

This class uses an indirect mechanism for implementing parameter properties. Each property get method calls a virtual protected method that retrieves the property. Each property set method, however, calls three virtual protected methods: one indicating that the property is changing, another actually changing the property, and a third indicating that the property has changed.

This allows the property setter to isolate the handling of invalid input in the property changing method, set the property, and apply any side effects in the property changed method. This also allows the base class to provide some default error checking to match the semantics defined by the parameter interface.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also

Reference

Microsoft.VisualStudio.Data.Framework Namespace

AdoDotNetParameter