LookupBindingPropertiesAttribute Class

Reference

Definition

Namespace:: System.ComponentModel

Assemblies:: netstandard.dll, System.ComponentModel.TypeConverter.dll

Assembly:: System.ComponentModel.TypeConverter.dll

Assembly:: System.dll

Assembly:: netstandard.dll

Source:: LookupBindingPropertiesAttribute.cs

Source:: LookupBindingPropertiesAttribute.cs

Source:: LookupBindingPropertiesAttribute.cs

Important

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Specifies the properties that support lookup-based binding. This class cannot be inherited.

public ref class LookupBindingPropertiesAttribute sealed : Attribute

[System.AttributeUsage(System.AttributeTargets.Class)]
public sealed class LookupBindingPropertiesAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.Class)>]
type LookupBindingPropertiesAttribute = class
    inherit Attribute

Public NotInheritable Class LookupBindingPropertiesAttribute
Inherits Attribute

Inheritance: Object

Attribute
LookupBindingPropertiesAttribute

Attributes: AttributeUsageAttribute

Examples

The following code example shows properties used with lookup-based binding.

// The DemoControl class shows properties 
// used with lookup-based binding.
[LookupBindingProperties(
    "DataSource", 
    "DisplayMember", 
    "ValueMember", 
    "LookupMember")]
public class DemoControl : Control
{   
}

' The DemoControl class shows properties 
' used with lookup-based binding.
<LookupBindingProperties( _
"DataSource", _
"DisplayMember", _
"ValueMember", _
"LookupMember")> _
Public Class DemoControl
    Inherits Control
End Class

The LookupBindingPropertiesAttribute attribute must include all four members, except when unsetting values. The following code example shows the ComboBox control.

// The DemoComboBox control shows a standard
// combo box binding definition.
[LookupBindingProperties(
    "DataSource", 
    "DisplayMember", 
    "ValueMember", 
    "SelectedValue")]
public class DemoComboBox : Control
{
}

' The DemoComboBox control shows a standard
' combo box binding definition.
<LookupBindingProperties( _
"DataSource", _
"DisplayMember", _
"ValueMember", _
"SelectedValue")> _
Public Class DemoComboBox
    Inherits Control
End Class

The following code example shows that a control can support both simple binding as well as list binding.

// The DemoComboBox2 class shows that a control can
// support both simple binding as well as list binding.
[LookupBindingProperties(
    "DataSource", 
    "DisplayMember", 
    "ValueMember", 
    "SelectedValue")]
[DefaultBindingProperty("Text")]
public class DemoComboBox2 : Control 
{
}

' The DemoComboBox2 class shows that a control can
' support both simple binding as well as list binding.
<LookupBindingProperties( _
"DataSource", _
"DisplayMember", _
"ValueMember", _
"SelectedValue"), _
DefaultBindingProperty("Text")> _
Public Class DemoComboBox2
    Inherits Control
End Class

The following code example shows that the LookupBindingPropertiesAttribute attribute can be unset by specifying no arguments.

// NonBindableCombo control shows how to unset the
// LookupBindingProperties by specifying no arguments.
[LookupBindingProperties()]
public class NonBindableCombo : Control
{
}

' NonBindableCombo control shows how to unset the
' LookupBindingProperties by specifying no arguments.
<LookupBindingProperties()>  _
Public Class NonBindableCombo
    Inherits Control
End Class

Remarks

The LookupBindingPropertiesAttribute is used to specify the properties used with lookup-based binding, particularly ListBox and ComboBox controls.

The LookupBindingPropertiesAttribute is specified at the class level. The class can be inherited and does not allow multiple attributes on the same class.

Constructors

LookupBindingPropertiesAttribute()	Initializes a new instance of the LookupBindingPropertiesAttribute class using no parameters.
LookupBindingPropertiesAttribute(String, String, String, String)	Initializes a new instance of the LookupBindingPropertiesAttribute class.

Fields

Default

Represents the default value for the LookupBindingPropertiesAttribute class.

Properties

DataSource	Gets the name of the data source property for the component to which the LookupBindingPropertiesAttribute is bound.
DisplayMember	Gets the name of the display member property for the component to which the LookupBindingPropertiesAttribute is bound.
LookupMember	Gets the name of the lookup member for the component to which this attribute is bound.
TypeId	When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute)
ValueMember	Gets the name of the value member property for the component to which the LookupBindingPropertiesAttribute is bound.

Methods

Equals(Object)	Determines whether the specified Object is equal to the current LookupBindingPropertiesAttribute instance.
GetHashCode()	Returns the hash code for this instance.
GetType()	Gets the Type of the current instance. (Inherited from Object)
IsDefaultAttribute()	When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute)
Match(Object)	When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)

Explicit Interface Implementations

_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)	Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)	Retrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute)
_Attribute.GetTypeInfoCount(UInt32)	Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)	Provides access to properties and methods exposed by an object. (Inherited from Attribute)

Applies to

Termék	Verziók
.NET	Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework	2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	2.0, 2.1

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