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.DataParameter
    Microsoft.VisualStudio.Data.AdoDotNet.AdoDotNetParameter

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

Syntax

'Déclaration
Public MustInherit Class DataParameter

public abstract class DataParameter

public ref class DataParameter abstract

[<AbstractClass>]
type DataParameter =  class end

public abstract class DataParameter

The DataParameter type exposes the following members.

Constructors

	Name	Description
	DataParameter()	Class constructor. Initializes a nonparameterized instance of the DataParameter class.
	DataParameter(Boolean)	Class constructor. Initializes a parameterized instance of the DataParameter class, along with an indication whether the instance was derived using the DeriveParameters method.

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Properties

	Name	Description
	DefaultPrecision	Retrieves a byte value specifying the default precision for the current parameter type.
	DefaultScale	Retrieves a byte value specifying the default scale for the current parameter type.
	DefaultSize	Retrieves and integer value specifying the default size for the current parameter type.
	Direction	Retrieves or sets a DataParameterDirection object specifying the direction of the parameter.
	IsDerived	Retrieves a Boolean value that indicates whether this parameter was derived from the data source.
	IsFixedPrecision	Retrieves a Boolean value indicating whether the precision for the current parameter type is fixed.
	IsFixedScale	Retrieves a Boolean value indicating whether the scale for the current parameter type is fixed.
	IsFixedSize	Retrieves a Boolean value indicating whether the size for the current parameter type is fixed.
	IsNullable	Retrieves a Boolean value indicating whether this parameter can have a nulla null reference (Nothing in Visual Basic) value.
	IsOptional	Retrieves a Boolean value indicating whether this parameter is optional, in cases where this parameter is a derived parameter.
	Name	Retrieves or sets the string literal name of the parameter.
	Precision	Retrieves or sets a byte value specifying the precision of the parameter.
	Scale	Retrieves or sets a byte value specifying the scale of the parameter.
	Size	Retrieves or sets an integer value specifying the size of the parameter.
	Type	Retrieves or sets the data-source-specific type of the parameter.
	Value	Retrieves or sets the value of the parameter.

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Methods

	Name	Description
	Equals	Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	GetDirectionImpl	Retrieves the parameter direction.
	GetHashCode	Serves as a hash function for a particular type. (Inherited from Object.)
	GetIsNullableImpl	Retrieves a Boolean value indicating whether or not this parameter can be nulla null reference (Nothing in Visual Basic).
	GetIsOptionalImpl	Retrieves a Boolean value indicating whether this parameter is optional.
	GetNameImpl	Retrieves the name of the parameter.
	GetPrecisionImpl	Retrieves a byte value specifying the precision of the parameter.
	GetScaleImpl	Retrieves a byte value specifying the scale of the parameter.
	GetSizeImpl	Retrieves an integer value specifying the size of the parameter.
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	GetTypeFrom	Infers the data-source-specific parameter type from a parameter value.
	GetTypeImpl	Retrieves the data-source-specific type of the parameter.
	GetValueImpl	Retrieves the value of a specified parameter.
	IsSupportedDirection	Retrieves a Boolean value indicating whether the specified parameter direction is supported.
	IsValidType	Retrieves a Boolean value indicating whether the specified data-source-specific type is a valid type.
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	OnDirectionChanged	Called when the Direction property is changed to signal a change in the parameter direction.
	OnDirectionChanging	Called when the Direction property is about to change.
	OnNameChanged	Called when the Name property has changed.
	OnNameChanging	Called when the Name property is about to change.
	OnPrecisionChanged	Called when the Precision property has changed.
	OnPrecisionChanging	Called when the Precision property is about to change.
	OnScaleChanged	Called when the Scale property has changed.
	OnScaleChanging	Called when the Scale property is about to change.
	OnSizeChanged	Called when the Size property has changed.
	OnSizeChanging	Called when the Size property is about to change.
	OnTypeChanged	Called when the Type property has changed.
	OnTypeChanging	Called when the Type property is about to change.
	OnValueChanged	Called when the Value property has changed.
	OnValueChanging	Called when the Value property is about to change.
	Parse	Disassembles a parameter value in a string format and converts the value to the correct type.
	SetDirectionImpl	Sets the direction of the parameter using the DataParameterDirection enumeration.
	SetNameImpl	Sets the name of the parameter.
	SetPrecisionImpl	Sets a byte value specifying the precision of the parameter.
	SetScaleImpl	Sets a byte value specifying the scale of the parameter.
	SetSizeImpl	Sets an integer value specifying the size of this parameter.
	SetTypeImpl	Sets the data type of this parameter.
	SetValueImpl	Sets the value of this parameter.
	ToString	Retrieves a string representation of the value of this parameter. (Overrides Object.ToString().)
	TryConvertValue	Attempts to convert the specified value to the specified type.

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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, on the other hand, 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 Namespace

AdoDotNetParameter