[英]How can I bind to a property from the Selected Item of a ComboBox?
我試圖創建一個用戶控件,以允許用戶在應用程序中定義自己的自定義線性漸變。
到目前為止,我有一個用戶控件,該控件使用以下模型來定義漸變停止的集合:
public class StopSelectorModel : INotifyPropertyChanged {
#region Field Values
private Task _PropertyT;
private ObservableCollection<GradientStop> _Stops;
private GradientStop _SelectedStop;
public event PropertyChangedEventHandler PropertyChanged;
#endregion
#region Properties
/// <summary>
/// Get or Set Gradient Stop Collection.
/// </summary>
public ObservableCollection<GradientStop> Stops {
get { return this._Stops; }
set {
this._Stops = value;
this._SelectedStop = value.FirstOrDefault( );
this._PropertyT = Task.WhenAll( new Task[ ] {
this.OnPropertyChanged( "Stops" ),
this.OnPropertyChanged( "SelectedStop" )
} );
}
}
/// <summary>
/// Get or Set Selected Gradient Stop.
/// </summary>
public GradientStop SelectedStop {
get { return this._SelectedStop; }
set {
if ( value == null )
return;
if ( !this._Stops.Contains( value ) )
this._Stops.Add( value );
this._SelectedStop = value;
this._PropertyT = this.OnPropertyChanged( "SelectedStop" );
}
}
#endregion
#region Methods
protected async Task OnPropertyChanged( string P ) {
if ( this.PropertyChanged != null )
await this.PropertyChanged.Async( this, new PropertyChangedEventArgs( P ) );
}
#endregion
#region Constructors
/// <summary>
/// Declare instance of StopSelectorModel.
/// </summary>
/// <param name="Base">GradientStopCollection to wrap.</param>
public StopSelectorModel( ObservableCollection<GradientStop> Base ) { this.Stops = Base; }
/// <summary>
/// Declare default instance of StopSelectorModel.
/// </summary>
public StopSelectorModel( ) : this( new ObservableCollection<GradientStop>( new GradientStop[ ] {
new GradientStop( Colors.White, 0.0D ),
new GradientStop( Colors.Black, 1.0D )
} ) ) { }
#endregion
}
我將其用作ComboBox的DataContext(據我所知,ItemSource = Stops,SelectedItem = SelectedStop,雙向綁定,用於此類操作的標准操作程序)。
我還有一個控件,該控件使用以下顏色模型定義顏色(基本上是4個滑動條):
/// <summary>
/// Wrapper for allowing complete databinding of a System.Windows.Media.Color struct.
/// </summary>
public class ColorModel : INotifyPropertyChanged {
private Task _PropertyT;
private Color _Color;
/// <summary>
/// Get or Set Context Color.
/// </summary>
public Color Color {
get { return this._Color; }
set {
this._Color = value;
this._PropertyT = Task.WhenAll( new Task[ ] {
this.OnPropertyChanged( "Color" ),
this.OnPropertyChanged( "ScA" ),
this.OnPropertyChanged( "ScR" ),
this.OnPropertyChanged( "ScG" ),
this.OnPropertyChanged( "ScB" ),
} );
}
}
/// <summary>
/// Get or Set Color ScA value.
/// </summary>
public double ScA {
get { return this._Color.ScA; }
set {
this._Color.ScA = ( float )value;
this._PropertyT = Task.WhenAll( new Task[ ] {
this.OnPropertyChanged( "Color" ),
this.OnPropertyChanged( "ScA" ),
} );
}
}
/// <summary>
/// Get or Set Color ScR value.
/// </summary>
public double ScR {
get { return this._Color.ScR; }
set {
this._Color.ScR = ( float )value;
this._PropertyT = Task.WhenAll( new Task[ ] {
this.OnPropertyChanged( "Color" ),
this.OnPropertyChanged( "ScR" ),
} );
}
}
/// <summary>
/// Get or Set Color ScG value.
/// </summary>
public double ScG {
get { return this._Color.ScG; }
set {
this._Color.ScG = ( float )value;
this._PropertyT = Task.WhenAll( new Task[ ] {
this.OnPropertyChanged( "Color" ),
this.OnPropertyChanged( "ScG" ),
} );
}
}
/// <summary>
/// Get or Set Color ScB value.
/// </summary>
public double ScB {
get { return this._Color.ScB; }
set {
this._Color.ScB = ( float )value;
this._PropertyT = Task.WhenAll( new Task[ ] {
this.OnPropertyChanged( "Color" ),
this.OnPropertyChanged( "ScB" ),
} );
}
}
protected async Task OnPropertyChanged( string P ) {
await this.PropertyChanged?.Async(
this, new PropertyChangedEventArgs( P ) ).DontBlock( );
}
public event PropertyChangedEventHandler PropertyChanged;
/// <summary>
/// Define ColorModel with default White Color.
/// </summary>
public ColorModel( ) : this( Colors.White ) { }
/// <summary>
/// Define ColorModel with provided color.
/// </summary>
/// <param name="C">Color to assign to ColorModel.</param>
public ColorModel( Color C ) { this.Color = C; }
}
因此,在這里...我如何將ComboBox的SelectedItem的Color屬性與此ColorModel綁定在一起? (如有必要,將提供更多詳細信息,但時間會很短)。
提前謝謝你的幫助...
為了清楚起見,我想將SelectedValue(Color)傳遞給控件,該控件將能夠編輯該顏色。
因此,操作的順序將是使ComboBox選擇漸變停止點之一,然后(這是我需要幫助的地方)負責調整顏色值的控件。
如果我理解正確,那么您希望獲得選擇項目時顯示的所選漸變顏色。
我將為其創建自己的DataTemplate,並在GradientStop中將顏色設置為運行時構建顏色的綁定。 取決於您是否希望所有組合框項目都着色,這可能會有所幫助: 我可以對WPF組合框中的所選項目使用與下拉部分中的項目不同的模板嗎?
編輯
作為對編輯的回應:如果我理解正確的話,您將獲得DataContext是UserControlModel的UserControl,其子級為StopSelectorModel,在這種情況下,我將設置SelectedGradientStop上的raising事件並在UserControlModel中處理此事件。
或者,如果不是兒童與父母的關系,則在設置SelectedGradientStop時,我將使用Messanger並發送消息。
事件和消息都必須包含描述應使用哪種顏色的對象。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.