這是一個很長的問題,所以請耐心等待。Caliburn.Micro嵌套ViewModels最佳實踐
目前我正在開發一個小工具,旨在幫助我跟蹤故事中無數的角色。
該工具執行以下操作:
- 負載當前存儲爲列表中,這是在殼經由一個列表框呈現的磁盤,並將它們存儲在JSON的字符。
- 如果用戶隨後打開一個字符,則爲
Conductor<Screen>.Collection.OneActive
的外殼會打開一個新的CharacterViewModel
,該派生自該字符。 Character
獲取將通過IEventAggregator
消息系統打開的字符。CharacterViewModel
還具有各種屬性,它們是綁定到各種子視圖的子視圖模型。
這裏是我的問題: 目前我手動初始化子的ViewModels當ChracterViewModel
被初始化。但是,這聽起來很腥,我很確定有更好的方法來做到這一點,但我不明白我該怎麼做。
這裏是CharacterViewModel
的代碼:
/// <summary>ViewModel for the character view.</summary>
public class CharacterViewModel : Screen, IHandle<DataMessage<ICharacterTagsService>>
{
// --------------------------------------------------------------------------------------------------------------------
// Fields
// -------------------------------------------------------------------------------------------------------------------
/// <summary>The event aggregator.</summary>
private readonly IEventAggregator eventAggregator;
/// <summary>The character tags service.</summary>
private ICharacterTagsService characterTagsService;
// --------------------------------------------------------------------------------------------------------------------
// Constructors & Destructors
// -------------------------------------------------------------------------------------------------------------------
/// <summary>Initializes a new instance of the <see cref="CharacterViewModel"/> class.</summary>
public CharacterViewModel()
{
if (Execute.InDesignMode)
{
this.CharacterGeneralViewModel = new CharacterGeneralViewModel();
this.CharacterMetadataViewModel = new CharacterMetadataViewModel();
}
}
/// <summary>Initializes a new instance of the <see cref="CharacterViewModel"/> class.</summary>
/// <param name="eventAggregator">The event aggregator.</param>
[ImportingConstructor]
public CharacterViewModel(IEventAggregator eventAggregator)
: this()
{
this.eventAggregator = eventAggregator;
this.eventAggregator.Subscribe(this);
}
// --------------------------------------------------------------------------------------------------------------------
// Properties
// -------------------------------------------------------------------------------------------------------------------
/// <summary>Gets or sets the character.</summary>
public Character Character { get; set; }
/// <summary>Gets or sets the character general view model.</summary>
public CharacterGeneralViewModel CharacterGeneralViewModel { get; set; }
/// <summary>Gets or sets the character metadata view model.</summary>
public CharacterMetadataViewModel CharacterMetadataViewModel { get; set; }
/// <summary>Gets or sets the character characteristics view model.</summary>
public CharacterApperanceViewModel CharacterCharacteristicsViewModel { get; set; }
/// <summary>Gets or sets the character family view model.</summary>
public CharacterFamilyViewModel CharacterFamilyViewModel { get; set; }
// --------------------------------------------------------------------------------------------------------------------
// Methods
// -------------------------------------------------------------------------------------------------------------------
/// <summary>Saves a character to the file system as a json file.</summary>
public void SaveCharacter()
{
ICharacterSaveService saveService = new JsonCharacterSaveService(Constants.CharacterSavePathMyDocuments);
saveService.SaveCharacter(this.Character);
this.characterTagsService.AddTags(this.Character.Metadata.Tags);
this.characterTagsService.SaveTags();
}
/// <summary>Called when initializing.</summary>
protected override void OnInitialize()
{
this.CharacterGeneralViewModel = new CharacterGeneralViewModel(this.eventAggregator);
this.CharacterMetadataViewModel = new CharacterMetadataViewModel(this.eventAggregator, this.Character);
this.CharacterCharacteristicsViewModel = new CharacterApperanceViewModel(this.eventAggregator, this.Character);
this.CharacterFamilyViewModel = new CharacterFamilyViewModel(this.eventAggregator);
this.eventAggregator.PublishOnUIThread(new CharacterMessage
{
Data = this.Character
});
base.OnInitialize();
}
/// <summary>
/// Handles the message.
/// </summary>
/// <param name="message">The message.</param>
public void Handle(DataMessage<ICharacterTagsService> message)
{
this.characterTagsService = message.Data;
}
}
完成的緣故,我也給你分的ViewModels之一。其他人不重要,因爲他們的結構相同,只是執行不同的任務。
/// <summary>The character metadata view model.</summary>
public class CharacterMetadataViewModel : Screen
{
/// <summary>The event aggregator.</summary>
private readonly IEventAggregator eventAggregator;
/// <summary>Initializes a new instance of the <see cref="CharacterMetadataViewModel"/> class.</summary>
public CharacterMetadataViewModel()
{
if (Execute.InDesignMode)
{
this.Character = DesignData.LoadSampleCharacter();
}
}
/// <summary>Initializes a new instance of the <see cref="CharacterMetadataViewModel"/> class.</summary>
/// <param name="eventAggregator">The event aggregator.</param>
/// <param name="character">The character.</param>
public CharacterMetadataViewModel(IEventAggregator eventAggregator, Character character)
{
this.Character = character;
this.eventAggregator = eventAggregator;
this.eventAggregator.Subscribe(this);
}
/// <summary>Gets or sets the character.</summary>
public Character Character { get; set; }
/// <summary>
/// Gets or sets the characters tags.
/// </summary>
public string Tags
{
get
{
return string.Join("; ", this.Character.Metadata.Tags);
}
set
{
char[] delimiters = { ',', ';', ' ' };
List<string> tags = value.Split(delimiters, StringSplitOptions.RemoveEmptyEntries).ToList();
this.Character.Metadata.Tags = tags;
this.NotifyOfPropertyChange(() => this.Tags);
}
}
}
我已經讀上Screens, Conductors and Composition,IResult and Coroutines和脫脂文檔的其餘部分,但不知何故,我無法找到我所期待的。
//編輯:我應該提到我的代碼工作得很好。我只是不滿意它,因爲我認爲我不理解MVVM的概念是非常正確的,因此做出錯誤的代碼。
有一個視圖模型實例化一個或多個其他視圖模型是很正常的。 – Sheridan 2014-09-03 19:49:19