我认为，在这种情况下，问题不在Catel. 每次切换选项卡时的标准TabControl卸载和重新加载 VisualTree 。这意味着每次您转到选项卡时，都会重新渲染 View，因此会影响性能，如果 View 很重，则更是如此。Content
如果您为内容Loaded事件处理程序创建，您可以看到这一点，如下所示：
<TabControl>
<TabItem Header="Worker">
<ContentControl Name="Content1"
Loaded="Content1_Loaded" />
</TabItem>
<TabItem Header="Business">
<ContentControl Name="Content2"
Loaded="Content2_Loaded"/>
</TabItem>
</TabControl>
每次在选项卡之间切换时都会触发这些事件。
作为替代方案，您可以尝试TabControl在程序启动时仅加载一次选项卡内容的实现。我在这个答案中找到了一个：
在 MVVM 应用程序中的视图之间导航时如何保留视图的完整状态？
这是清单：
Class TabControlEx
[TemplatePart(Name = "PART_ItemsHolder", Type = typeof(Panel))]
public class TabControlEx : TabControl
{
private Panel ItemsHolderPanel = null;
public TabControlEx()
: base()
{
// This is necessary so that we get the initial databound selected item
ItemContainerGenerator.StatusChanged += ItemContainerGenerator_StatusChanged;
}
/// <summary>
/// If containers are done, generate the selected item
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ItemContainerGenerator_StatusChanged(object sender, EventArgs e)
{
if (this.ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated)
{
this.ItemContainerGenerator.StatusChanged -= ItemContainerGenerator_StatusChanged;
UpdateSelectedItem();
}
}
/// <summary>
/// Get the ItemsHolder and generate any children
/// </summary>
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
ItemsHolderPanel = GetTemplateChild("PART_ItemsHolder") as Panel;
UpdateSelectedItem();
}
/// <summary>
/// When the items change we remove any generated panel children and add any new ones as necessary
/// </summary>
/// <param name="e"></param>
protected override void OnItemsChanged(NotifyCollectionChangedEventArgs e)
{
base.OnItemsChanged(e);
if (ItemsHolderPanel == null)
return;
switch (e.Action)
{
case NotifyCollectionChangedAction.Reset:
ItemsHolderPanel.Children.Clear();
break;
case NotifyCollectionChangedAction.Add:
case NotifyCollectionChangedAction.Remove:
if (e.OldItems != null)
{
foreach (var item in e.OldItems)
{
ContentPresenter cp = FindChildContentPresenter(item);
if (cp != null)
ItemsHolderPanel.Children.Remove(cp);
}
}
// Don't do anything with new items because we don't want to
// create visuals that aren't being shown
UpdateSelectedItem();
break;
case NotifyCollectionChangedAction.Replace:
throw new NotImplementedException("Replace not implemented yet");
}
}
protected override void OnSelectionChanged(SelectionChangedEventArgs e)
{
base.OnSelectionChanged(e);
UpdateSelectedItem();
}
private void UpdateSelectedItem()
{
if (ItemsHolderPanel == null)
return;
// Generate a ContentPresenter if necessary
TabItem item = GetSelectedTabItem();
if (item != null)
CreateChildContentPresenter(item);
// show the right child
foreach (ContentPresenter child in ItemsHolderPanel.Children)
child.Visibility = ((child.Tag as TabItem).IsSelected) ? Visibility.Visible : Visibility.Collapsed;
}
private ContentPresenter CreateChildContentPresenter(object item)
{
if (item == null)
return null;
ContentPresenter cp = FindChildContentPresenter(item);
if (cp != null)
return cp;
// the actual child to be added. cp.Tag is a reference to the TabItem
cp = new ContentPresenter();
cp.Content = (item is TabItem) ? (item as TabItem).Content : item;
cp.ContentTemplate = this.SelectedContentTemplate;
cp.ContentTemplateSelector = this.SelectedContentTemplateSelector;
cp.ContentStringFormat = this.SelectedContentStringFormat;
cp.Visibility = Visibility.Collapsed;
cp.Tag = (item is TabItem) ? item : (this.ItemContainerGenerator.ContainerFromItem(item));
ItemsHolderPanel.Children.Add(cp);
return cp;
}
private ContentPresenter FindChildContentPresenter(object data)
{
if (data is TabItem)
data = (data as TabItem).Content;
if (data == null)
return null;
if (ItemsHolderPanel == null)
return null;
foreach (ContentPresenter cp in ItemsHolderPanel.Children)
{
if (cp.Content == data)
return cp;
}
return null;
}
protected TabItem GetSelectedTabItem()
{
object selectedItem = base.SelectedItem;
if (selectedItem == null)
return null;
TabItem item = selectedItem as TabItem;
if (item == null)
item = base.ItemContainerGenerator.ContainerFromIndex(base.SelectedIndex) as TabItem;
return item;
}
}
Style
为了更好地显示，我对其进行了一些修改：
<Style TargetType="{x:Type this:TabControlEx}">
<Setter Property="Background" Value="Transparent" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type TabControl}">
<Grid Background="{TemplateBinding Background}"
ClipToBounds="True"
KeyboardNavigation.TabNavigation="Local"
SnapsToDevicePixels="True">
<Grid.ColumnDefinitions>
<ColumnDefinition x:Name="ColumnDefinition0" />
<ColumnDefinition x:Name="ColumnDefinition1" Width="0" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition x:Name="RowDefinition0" Height="Auto" />
<RowDefinition x:Name="RowDefinition1" Height="*" />
</Grid.RowDefinitions>
<DockPanel Margin="2,2,0,0"
LastChildFill="False">
<TabPanel x:Name="HeaderPanel"
Margin="0,0,0,-1"
VerticalAlignment="Bottom"
Panel.ZIndex="1"
DockPanel.Dock="Left"
IsItemsHost="True"
KeyboardNavigation.TabIndex="1" />
</DockPanel>
<Border x:Name="ContentPanel"
Grid.Row="1"
Grid.Column="0"
Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
KeyboardNavigation.DirectionalNavigation="Contained"
KeyboardNavigation.TabIndex="2"
KeyboardNavigation.TabNavigation="Local">
<Grid x:Name="PART_ItemsHolder"
Margin="{TemplateBinding Padding}"
SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />
</Border>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
Some notes
就个人而言，我总是使用DataTemplateas View。因为 UserControl 是一个“重量级”控件，所以它变得更加动态并且对性能的影响更小，我意识到它非常罕见 - 当需要创建一个单独的控件时，例如DatePicker.
因此，作为另一条建议：如果可能，请在 DataTemplate 下重新制作您的视图并将它们加载到ContentControl. 我认为使用DataTemplateandTabControlEx可以显着提高整个应用程序的性能。
Update
Mr.@Geert van Horrik在评论中提到Catel确实提供了这个实现以及Catel.Windows.Controls.TabControl. 我认为你应该先检查一下。