Class ObservingCommand

Describes a command that observes an object implementing INotifyPropertyChanged and listens for any changes to its property values to automatically enable or disable command execution.

Inheritance

object

CommandBase

ObservingCommand

Implements

ICommand

Inherited Members

CommandBase.CanExecuteChanged

CommandBase.CanExecute()

CommandBase.Execute(object)

CommandBase.Execute()

CommandBase.TryExecute(object)

CommandBase.TryExecute()

CommandBase.RaiseCanExecuteChanged()

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: TheXDS.MCART.Component

Assembly: MCART.Mvvm.dll

Syntax

public class ObservingCommand : CommandBase, ICommand

Constructors

ObservingCommand(INotifyPropertyChanged, Action)

Initializes a new instance of ObservingCommand.

Declaration

public ObservingCommand(INotifyPropertyChanged observedSource, Action action)

Parameters

Type	Name	Description
INotifyPropertyChanged	observedSource	The data source to observe.
Action	action	The action to execute.

ObservingCommand(INotifyPropertyChanged, Action<object?>)

Describes a command that observes an object implementing INotifyPropertyChanged and listens for any changes to its property values to automatically enable or disable command execution.

Declaration

public ObservingCommand(INotifyPropertyChanged observedSource, Action<object?> action)

Parameters

Type	Name	Description
INotifyPropertyChanged	observedSource	The data source to observe.
Action<object>	action	The action to execute.

ObservingCommand(INotifyPropertyChanged, Func<object?, Task>)

Initializes a new instance of ObservingCommand.

Declaration

public ObservingCommand(INotifyPropertyChanged observedSource, Func<object?, Task> task)

Parameters

Type	Name	Description
INotifyPropertyChanged	observedSource	The data source to observe.
Func<object, Task>	task	The asynchronous task to execute.

ObservingCommand(INotifyPropertyChanged, Func<Task>)

Initializes a new instance of ObservingCommand.

Declaration

public ObservingCommand(INotifyPropertyChanged observedSource, Func<Task> task)

Parameters

Type	Name	Description
INotifyPropertyChanged	observedSource	The data source to observe.
Func<Task>	task	The asynchronous task to execute.

Properties

ObservedProperties

Enumerates the property names being observed by this ObservingCommand.

Declaration

public IEnumerable<string> ObservedProperties { get; }

Property Value

Type	Description
IEnumerable<string>

ObservedSource

Reference to the data source observed by this ObservingCommand.

Declaration

public INotifyPropertyChanged ObservedSource { get; }

Property Value

Type	Description
INotifyPropertyChanged

Methods

CanExecute(object?)

Sets the method that determines whether the command can execute in its current state.

Declaration

public override bool CanExecute(object? parameter)

Parameters

Type	Name	Description
object	parameter	Data used by the command. If the command does not require data, this object can be set to null.

Returns

Type	Description
bool	true if this command can execute; otherwise, false.

Overrides

CommandBase.CanExecute(object?)

RegisterObservedProperty(Expression<Func<object?>>)

Registers a property to observe for this command using a lambda expression that selects the property.

Declaration

public ObservingCommand RegisterObservedProperty(Expression<Func<object?>> property)

Parameters

Type	Name	Description
Expression<Func<object>>	property	Expression selecting the property to observe.

Returns

Type	Description
ObservingCommand	This same instance, allowing fluent call chaining.

RegisterObservedProperty(params string[])

Registers one or more property names to observe for this command.

Declaration

public ObservingCommand RegisterObservedProperty(params string[] properties)

Parameters

Type	Name	Description
string[]	properties	The name(s) of the property(ies) to observe.

Returns

Type	Description
ObservingCommand	This same instance to allow fluent usage.

SetCanExecute(Func<bool>)

Sets the check function used to determine whether the command can execute.

Declaration

public ObservingCommand SetCanExecute(Func<bool> canExecute)

Parameters

Type	Name	Description
Func<bool>	canExecute	Function used to determine whether the command can execute.

Returns

Type	Description
ObservingCommand	This same instance, allowing fluent call chaining.

SetCanExecute(Func<INotifyPropertyChanged, object?, bool>?)

Sets the check function used to determine whether the command can execute.

Declaration

public ObservingCommand SetCanExecute(Func<INotifyPropertyChanged, object?, bool>? canExecute)

Parameters

Type	Name	Description
Func<INotifyPropertyChanged, object, bool>	canExecute	Function that receives the observed source and the command parameter and returns whether the command can execute. Pass null to remove the check.

Returns

Type	Description
ObservingCommand	This same instance, allowing fluent call chaining.

SetCanExecute(Func<object?, bool>)

Sets the check function used to determine whether the command can execute.

Declaration

public ObservingCommand SetCanExecute(Func<object?, bool> canExecute)

Parameters

Type	Name	Description
Func<object, bool>	canExecute	Function that receives the command parameter and returns whether the command can execute.

Returns

Type	Description
ObservingCommand	This same instance, allowing fluent call chaining.

UnsetCanExecute()

Disconnects the check function used to determine whether the command can execute.

Declaration

public void UnsetCanExecute()

Implements

ICommand

Extension Methods

Objects.ShallowCopyTo(object, object, Type)

ObjectExtensions.FieldsOf<T>(object)

ObjectExtensions.GetAttribute<T>(object)

ObjectExtensions.GetAttributes<T>(object)

ObjectExtensions.HasAttrValue<TAttribute, TValue>(object, out TValue)

ObjectExtensions.HasAttribute<T>(object)

ObjectExtensions.HasAttribute<T>(object, out T?)

ObjectExtensions.HasAttributes<T>(object, out IEnumerable<T>?)

ObjectExtensions.Is(object?, object?)

ObjectExtensions.IsEither(object, IEnumerable)

ObjectExtensions.IsEither(object, params object[])

ObjectExtensions.IsNeither(object, IEnumerable)

ObjectExtensions.IsNeither(object, params object[])

ObjectExtensions.IsNot(object?, object?)

ObjectExtensions.PropertiesOf<T>(object)

ObjectExtensions.WhichAre(object, IEnumerable<object>)

ObjectExtensions.WhichAre(object, params object[])

Common.IfNotNull<T>(T?, Action<T>)

Objects.Itself<T>(T)

Objects.ShallowCopyTo<T>(T, T)

CollectionExtensions.PushInto<TItem, TCollection>(TItem, ICollection<TCollection>)

DictionaryExtensions.PushInto<TKey, TValue>(TValue, TKey, IDictionary<TKey, TValue>)

ObservingCommandExtensions.CanExecuteIfNotDefault(ObservingCommand, params Expression<Func<ValueType>>[])

ObservingCommandExtensions.CanExecuteIfNotDefault<T>(ObservingCommand, params Expression<Func<T, ValueType>>[])

ObservingCommandExtensions.CanExecuteIfNotNull(ObservingCommand, params Expression<Func<object?>>[])

ObservingCommandExtensions.CanExecuteIfNotNull<T>(ObservingCommand, params Expression<Func<T, object?>>[])

ObservingCommandExtensions.ListensToCanExecute(ObservingCommand, Expression<Func<bool>>)

ObservingCommandExtensions.ListensToCanExecute<T>(ObservingCommand, Expression<Func<T, bool>>)

ObservingCommandExtensions.ListensToProperties(ObservingCommand, params Expression<Func<object?>>[])

ObservingCommandExtensions.ListensToProperties<TProperty>(ObservingCommand, params Expression<Func<TProperty>>[])

ObservingCommandExtensions.ListensToProperties<T>(ObservingCommand, params Expression<Func<T, object?>>[])

ObservingCommandExtensions.ListensToProperties<T, TProperty>(ObservingCommand, params Expression<Func<T, TProperty>>[])

ObservingCommandExtensions.ListensToProperty(ObservingCommand, Expression<Func<object?>>)

ObservingCommandExtensions.ListensToProperty<T>(ObservingCommand, Expression<Func<T, object?>>)