RFBCodeWorks.Mvvm.Controls 1.0.0.3

MvvmControls

This is a Library designed to ease working within an MVVM framework, and is meant to consolidate boiler-plate ViewModel interactions for common WPF controls into pre-built classes.

Mvvm.Primitive Classes

These classes are the base classes the main objects are derived from, and follow a strucute similar to System.Windows.Controls namespace.

• ControlBase : ObservableObject
  • Properties:- bool IsEnabled { get; set; }
    • bool IsVisible { get; set; }
    • Visibility Visibility { get; set; }
  • Events:
    • VisibilityChanged
• ItemSource<T,E> : ControlBase where E:IList<T>
  • Base class for an ItemSource control.
  • Type Parameters
    • T : The object that will be housed in the collection of type E
    • E : The collection type - Must implement IList<T>
  • Properties
    • string DisplayMemberPath - Set which property to display (for example, display the 'Name' in the combobox)
    • E Items - The collection of items
  • Events:
    • ItemSourceChanged - occurs when the Items property is set to a new collection
• SelectorDefinition<T,E,V> : ItemSource <T,E> where E:IList<T>
  • Extends the ItemSource<T,E> class for use with Selector controls, such as ComboBox and ListBox
  • Properties:
    • T SelectedItem -- The currently selected item
    • string SelectedValuePath -- Optional setting that allows setting a 'ValuePath' for the control to utilize. Ex: "ID" --> SelectedValue = SelectedItem.ID
    • V SelectedValue -- The currently selected value by the SelectedValuePath - This should be only set by the control, not in code.
  • Events:
    • SelectedItemChanged - Occurs when a new item is selected
    • SelectedValueChanged - Occurs when the SelectedValue property changes
• AbstractCommand, AbstractCommand<T>, AbstractAsyncCommand, AbstractAsyncCommand<T>
  • These are abstract ICommand objects that implement the Community Toolkit's IRelayCommand interface
• AbstractButtonDefinition, AbstractButtonDefinition<T>, AbstractAsyncButtonDefinition, AbstractAsyncButtonDefinition<T>
  • These are abstract classes that implement the IButtonDefinition & ICommand interfaces, for use with to bind with to the button control
• ToggleButtonDefinition
  • Base class for RadioButton and CheckBox button definitions

Concrete Classes

• ButtonDefinition, ButtonDefinition<T>, AsyncButtonDefinition, AsyncButtonDefinition<T>

  • These sealed classes are derived from their respective abstract versions.
  • They utilize IRelayCommand objects to implement ICommand.

• RelayCommand, RelayCommand<T>, AsyncRelayCommand, AsyncRelayCommand<T>

  • These ICommand objects are sealed, but are derived from their respective abstract primitives.

• ListBoxDefinition, ComboBoxDefinition - Derived from Primitives.SelectorDefinition

  • ListBox- and ComboBox- Definition objects are used to represent a user's interaction with a Listbox or ComboBox
  • Both extend Primitives.SelectorDefinition with properties specific to their associated controls.
  • With the WPF.Behaviors.MultiItemSelectionBehavior properties attached to a listbox, a Listbox also supports multi-item selection modes.

• CheckBoxDefinition, RadioButtonDefinition - Derived from Primitives.ToggleButton

  • CheckBoxDefinition is directly derived from Primitives.ToggleButton, and implements ICheckBox
  • RadioButton adds the 'GroupName' property, and implements IRadioButton.
  • RadioButton also overrides the IsThreeState property to FALSE.

• TextControlDefinition - Derived from Primitives.ControlBase

  • While a textbox would normally just be bound to a string, since this is derived from ControlBase, it allows for the enabling/disabling/visibility control over the textbox. Additional members include:
    • Func<string> GetText - A function that can be executed to set the Text property
    • string Text - The text to display in the textbox
    • bool IsReadOnly - Set the textbox to ReadOnly mode
    • Refresh() - Invokes GetText() to update the Text property
    • Refresh(object, eventargs) - Provides a way to automatically refresh the Text property by subscribing the object to an external event

A simplified ComboBox Experience

A ComboBox has the following properties that the ViewModel may interact with:

• ItemSource (The items within the drop-down)
• SelectedItem (The currently selected item)
• SelectedValue \ SelectedValuePath ( The value of the SelectedItem, as an object, typically a property of the item )
• SelectedItemChanged event - Occurs and a new item is selected
• ItemSourceChanged event - Occurs when the itemsource is updated
• IsEnabled - Enable/Disable a control from within the ViewModel
• Visibilty / IsVisible - Toggle visibility of an item from within the ViewModel

This can all be set up within the ViewModel like so:

public class MyViewModel {

  public MyViewModel()
  {
   MyComboBox = new ComboBoxDefinition<string>()
   {
     ItemSource = new string[] { "Index0", "Index1", "Index2", "Index3" }
   };
   ComboBoxDefinition.SelectedItemChanged += NewItemSelected;
  }
  public ComboBoxDefinition<string> MyComboBox { get; }

  private void NewItemSelected(object sender, EventArgs e) { /* React to item selection */ } 
}

And the corresponding xaml:

  xmlns:Behaviors="clr-namespace:RFBCodeWorks.WPF.Behaviors;assembly=RFBCodeWorks.Mvvm.Controls"

  <ComboBox Behaviors:ControlDefinitions.ComboBoxDefinition="{Binding ComboBoxDefinition}" />

Development Targets

This library utilizes C#9.0 for init setters.

• If a consumer is not using C#9, you can refer to the following guide: https://blog.ndepend.com/using-c9-record-and-init-property-in-your-net-framework-4-x-net-standard-and-net-core-projects/
• The file 'CSharp9_MissingComponents.cs' is already included within this library, so the file can just be included in your project to provide the necesary components, then include the following in your project file: <LangVersion>9.0</LangVersion>

Build Targets:

• .NetFramework net472, net480
• .NetCoreApp3.1
• .Net5.0-windows