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[英]Attaching ObservableCollection as ItemsSource of ItemsControl
[英]DataBinding an ItemsSource inside an ItemsControl
在wpf方面,我仍然將自己視為初學者。 我想知道兩件事
情況:[數據部分]我有:數據模型對象。 DataFilter對象,它基本上是DataModels +添加的函數的集合。 還有DataFiltersGroup,它用於DataViewModel中並具有DataFilters的集合,我有一個DataViewModel對象,該對象基本上是可觀察的項目集合。 我想在Itemscontrol中顯示每個DataFilter。
[當前解決方案]我已經構建了一個特殊的Combo控件,該控件從combobox(基本上是一個按鈕+ combobox)派生而來。 特意綁定時,combocombo可以正常工作。 因此,我非常有信心這個問題不在於特殊組合。 當我將ItemsControl.ItemsSource屬性設置為DataFilters的集合並制作SpecialCombo的DataTemplate時,組合框不顯示任何結果(如果沒有Items,則特殊組合將不顯示切換按鈕-僅顯示按鈕)。 一種替代方法-下面的綁定方法(2)讓我看到下拉切換按鈕,但是下拉菜單為空,但是我知道不應該這樣。
這是摘要的代碼摘錄
public class DataModel :INotifyPropertyChanged
{
//The Item!!
public int Index {//Normal get set property}
public string Name {//Normal get set property}
public int Parent {//Normal get set property}
public string FullName {//Normal get set property}
public string DisplayName {//Normal get set property}
public bool Static {//Normal get set property}
}
public class DataFilters : DataCollection
{
public ObservableCollection<DataModel> CombinedData;
public int FilterIndex{//Property... The index of the current item like Index for DataModel.}
public string ParentName {//property ButtonContent item}
public int SelectedItem {//Property}
}
//Used as part of DataVieModel. Also responsible of building each DataFilters item and some other functions
public class DataFilterGroup : INotifyPropertyChanged
{
public ObservableCollection<DataFilters> FullCollection;
}
WPF對象
<ItemsControl x:Name="PART_ListBox" HorizontalAlignment="Left" VerticalContentAlignment="Stretch" Margin="0">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<VirtualizingStackPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>
WPF加載后的代碼
//DVM = DataVieModel with some other objects. Filters = DataFilterGroup
PART_ListBox.ItemsSource = DVM.Filters.FullCollection;
PART_ListBox.ItemTemplate = DataFilterTemplate;
//And DataTemplate (1) - shows no combobox
private static DataTemplate DataFilterTemplate
{
get
{
DataTemplate DFT = new DataTemplate();
DFT.DataType = typeof(DataFilters);
FrameworkElementFactory Stack = new FrameworkElementFactory(typeof(VirtualizingStackPanel));
Stack.SetValue(VirtualizingStackPanel.OrientationProperty, Orientation.Horizontal);
FrameworkElementFactory Item = new FrameworkElementFactory(typeof(SpecialCombo));
Item.SetValue(SpecialCombo.ButtonContentProperty, new Binding("ParentName"));
Item.SetValue(SpecialCombo.ItemsSourceProperty, "CombinedData");
Item.SetValue(SpecialCombo.DisplayMemberPathProperty, "DisplayName");
Item.SetValue(SpecialCombo.SelectedValuePathProperty, "Index");
Item.SetValue(SpecialCombo.SelectedValueProperty, "SelectedItem");
//Item.SetValue(SpecialCombo.ToggleVisibleProperty, new Binding("ComboVisibility"));
//Item.SetValue(SpecialCombo.SelectedValueProperty, new Binding("SelectedItem"));
Stack.AppendChild(Item);
DFT.VisualTree = Stack;
return DFT;
}
}
//And DataTemplate (2) - shows combobox with no items in dropdown
private static DataTemplate DataFilterTemplate
{
get
{
DataTemplate DFT = new DataTemplate();
DFT.DataType = typeof(DataFilters);
FrameworkElementFactory Stack = new FrameworkElementFactory(typeof(VirtualizingStackPanel));
Stack.SetValue(VirtualizingStackPanel.OrientationProperty, Orientation.Horizontal);
FrameworkElementFactory Item = new FrameworkElementFactory(typeof(SpecialCombo));
Item.SetValue(SpecialCombo.ButtonContentProperty, new Binding("ParentName"));
Item.SetValue(SpecialCombo.ItemsSourceProperty, new Binding("CombinedData"));
Item.SetValue(SpecialCombo.DisplayMemberPathProperty, "DisplayName");
Item.SetValue(SpecialCombo.SelectedValuePathProperty, "Index");
Item.SetValue(SpecialCombo.SelectedValueProperty, "SelectedItem");
//Item.SetValue(SpecialCombo.ToggleVisibleProperty, new Binding("ComboVisibility"));
//Item.SetValue(SpecialCombo.SelectedValueProperty, new Binding("SelectedItem"));
Stack.AppendChild(Item);
DFT.VisualTree = Stack;
return DFT;
}
}
多虧了punker 76在另一篇文章中我對問題進行了結構調整(這里-> 可以從ItemsControl的數據模板綁定combobox Itemssource)嗎 ?
因此,DataFilters應該成為一個依賴對象
public class DataFilters : DataCollection
// should become
public class DataFilters : DependencyObject
Observalbe收集也應更改。 所以
public ObservableCollection<DataModel> CombinedData;
// should become
public static readonly DependencyProperty CombinedData= DependencyProperty.Register("CombinedData", typeof(ObservableCollection<DataModel>), typeof(DataFilters), new FrameworkPropertyMetadata());
//and should become a property
public ObservableCollection<DataModel> CombinedData
{
get { return (ObservableCollection<DataModel>)GetValue(CombinedDataProperty); }
set { SetValue(CombinedDataProperty, value); }
}
然后在DataTemplate文件中,以下內容應更改Item.SetValue(SpecialCombo.ItemsSourceProperty,“ CombinedData”); //應更改為Item.SetBinding(SpecialCombo.ItemsSourceProperty,new Binding(“ CombinedData”));
我還沒有遍歷上面的整個代碼,但是我認為,為了在DataTemplate中綁定組合框類型的項目,應該全部進行上述所有更改。
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