具有直接内容的自定义控件将传递到Commandbar

Question

我有一个自定义控件的想法，但我不知道如何实施它。

假设我有一个控制“ mycontrol”，其中有一个命令栏。

<Control ... MyControl>
    <Label Content="Hello" />

    <CommandBar>
        <DefaultButton Command={Binding DCom1} >
        <DefaultButton Command={Binding DCom2} >

        <SomePlaceHolderForAdditionalButtons />
    </CommandBar>
</Control>

我想执行以下操作：

<MyControl>
    <MyAdditionalButton Command={Binding Com1} />
    <MyAdditionalButton Command={Binding Com2} />
</MyControl>

之后，MyControl首先加载了两个默认按钮，而两个按钮作为第三个和第四个按钮。

不是 任何帮助都将受到赞赏。

Answer 1

MyControl首先加载两个默认按钮，两个按钮作为第三个和第四个按钮。

您可以使模板控制接近。自定义项目属性ustomcontrol，然后调用UpdateView方法将AppBarbutton Element将其推入Default Commandbar。

例如

[ContentProperty(Name = "Items")]
public class CustomControl : Control
{   
    private const string CommandBarPresenter = "CommandBarPresenter";
    public CustomControl()
    {
        this.DefaultStyleKey = typeof(CustomControl);
        var items = new ObservableCollection<object>();
        items.CollectionChanged += Items_CollectionChanged;
        Items = items;
    }

    private void Items_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        UpdateView();
    }

    public DataTemplate ItemTemplate
    {
        get { return (DataTemplate)GetValue(ItemTemplateProperty); }
        set { SetValue(ItemTemplateProperty, value); }
    }

    public static readonly DependencyProperty ItemTemplateProperty =
    DependencyProperty.Register("ItemTemplate", typeof(DataTemplate), typeof(CustomControl), new PropertyMetadata(null, OnItemTemplateChanged));

    private static void OnItemTemplateChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args)
    {
        CustomControl target = obj as CustomControl;
        DataTemplate oldValue = (DataTemplate)args.OldValue;
        DataTemplate newValue = (DataTemplate)args.NewValue;
        if (oldValue != newValue)
            target.OnItemTemplateChanged(oldValue, newValue);
    }

    protected virtual void OnItemTemplateChanged(DataTemplate oldValue, DataTemplate newValue)
    {
        UpdateView();
    }

    public ICollection<object> Items
    {
        get;
    }

    private CommandBar _commandBarPresenter;

    protected override void OnApplyTemplate()
    {
        base.OnApplyTemplate();

        _commandBarPresenter = GetTemplateChild(CommandBarPresenter) as CommandBar;
        UpdateView();
    }

    private void OnItemsCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        UpdateView();
    }

    protected virtual System.Boolean IsItemItsOwnContainerOverride(System.Object item)
    {
        return item is ContentPresenter;
    }


    protected virtual void PrepareICommandElementForItemOverride(DependencyObject element, System.Object item)
    {
        ContentControl contentControl;

        if ((contentControl = element as AppBarButton) != null)
        {
            contentControl.Content = item;
            contentControl.ContentTemplate = ItemTemplate;
        }

    }


    private void UpdateView()
    {

        if (_commandBarPresenter == null)
            return;

        foreach (var item in Items)
        {

            if (item is AppBarButton)
            {
                _commandBarPresenter.SecondaryCommands.Add(item as AppBarButton);
                break;
            }

            if (!(item is AppBarButton))
            {
                throw new Exception("please add AppBarButton as content");
            }

        }
    }
}

XAML代码

<Style TargetType="local:CustomControl" >
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="local:CustomControl">
                <StackPanel Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}">
                    <CommandBar x:Name="CommandBarPresenter">
                        <AppBarButton Icon="Add" Label="Add"/>
                        <AppBarButton Icon="Edit" Label="Edit"/>
                    </CommandBar>
                </StackPanel>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

用法

<local:CustomControl>
    <AppBarButton Icon="AlignCenter" Label="Center"/>
    <AppBarButton Icon="Cut" Label="Cut"/>
</local:CustomControl>