基于ItemsControl only shows first Item of each object我需要你的帮助。 解决方案非常顺利，但在度假和做其他事情后我需要修改它。
实际上有些对象（CanvasObject）在启动时/读取xml数据后绘制，其他（模块）从树视图放入画布。这些模块出现在画布视觉儿童中，但我无法在画布上看到它们。
到目前为止，这是我的代码 - 我尝试了不同的方法，但总是得到类似的结果：
C＃：
public class CanvasLine
{
public Point P1 { get; set; }
public Point P2 { get; set; }
public Brush Stroke { get; set; }
public double StrokeThickness { get; set; }
public DoubleCollection StrokeDashArray { get; set; }
}
public class CanvasObject
{
public String Name { get; set; }
public ObservableCollection<CanvasLine> CanvasLines { get; set; }
}
public class Module
{
public Dictionary<String, String> Attributes { get; set; }
public Point AnchorPoint { get; set; }
public Double Height { get; set; }
public Double Width { get; set; }
}
public class ViewModel
{
...
public ObservableCollection<Object> CanvasObjects;
...
}
Viewmodels ObservableCollection<Object>从xml中填充CanvasObjects - 这些正确显示。之后，我将模块添加到画布中，将模块添加到该集合中。这些似乎是在画布儿童集合中，但不可见。
这是相应的/清理过的XAML：
<ItemsControl Grid.Column="1" Grid.Row="2" Margin="0" ItemsSource="{Binding CanvasObjects, UpdateSourceTrigger=PropertyChanged}">
<ItemsControl.Resources>
<ScaleTransform x:Key="LineTransform"
ScaleX="{Binding ActualWidth,
RelativeSource={RelativeSource AncestorType=ItemsControl}}"
ScaleY="{Binding ActualWidth,
RelativeSource={RelativeSource AncestorType=ItemsControl}}"/>
</ItemsControl.Resources>
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<Canvas Background="Transparent" AllowDrop="True" Drop="Canvas_OnDrop"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplateSelector>
<xmlTemp:TemplateSelector>
<xmlTemp:TemplateSelector.ModuleTemplate>
<DataTemplate DataType="{x:Type xmlElements:Module}">
<ItemsControl ItemsSource="{Binding RelativeSource={RelativeSource Self}}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<Canvas/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemContainerStyle>
<Style TargetType="ContentPresenter">
<Setter Property="Canvas.Left" Value="{Binding AnchorPoint.X}"/>
<Setter Property="Canvas.Top" Value="{Binding AnchorPoint.Y}"/>
</Style>
</ItemsControl.ItemContainerStyle>
<ItemsControl.ItemTemplate>
<DataTemplate>
<Rectangle Width="{Binding Width}" Height="{Binding Height}" StrokeThickness="2" Fill="Black" Stroke="Black">
<Rectangle.RenderTransform>
<StaticResource ResourceKey="LineTransform"/>
</Rectangle.RenderTransform>
</Rectangle>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</DataTemplate>
</xmlTemp:TemplateSelector.ModuleTemplate>
<xmlTemp:TemplateSelector.LineObjectTemplate>
<DataTemplate DataType="{x:Type dt:CanvasObject}">
<ItemsControl ItemsSource="{Binding CanvasLines}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<Canvas/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<Path Stroke="{Binding Stroke}"
StrokeDashArray="{Binding StrokeDashArray}">
<Path.Data>
<LineGeometry
Transform="{StaticResource LineTransform}"
StartPoint="{Binding P1}"
EndPoint="{Binding P2}"/>
</Path.Data>
<Path.Style>
<Style TargetType="Path">
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="StrokeThickness">
<Setter.Value>
<MultiBinding Converter="{StaticResource MultiplicationConverter}">
<Binding Path="StrokeThickness" Mode="OneWay"/>
<Binding Source="3"/>
</MultiBinding>
</Setter.Value>
</Setter>
</Trigger>
<Trigger Property="IsMouseOver" Value="False">
<Setter Property="StrokeThickness" Value="{Binding StrokeThickness, Mode=OneWay}"/>
</Trigger>
</Style.Triggers>
</Style>
</Path.Style>
</Path>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</DataTemplate>
</xmlTemp:TemplateSelector.LineObjectTemplate>
</xmlTemp:TemplateSelector>
</ItemsControl.ItemTemplateSelector>
</ItemsControl>
以下是缺少的事件和模板选择器：
private void Canvas_OnDrop(Object sender, DragEventArgs e)
{
Module Module = e.Data.GetData("Module") as Module;
Canvas Canvas = sender as Canvas;
if (Module != null && Canvas != null)
{
Module.Width = 0.1;
Module.Height = 0.2;
Module.AnchorPoint = e.GetPosition(Canvas);
ViewModel.CanvasObjects.Add(Module);
}
}
public class TemplateSelector : DataTemplateSelector
{
public DataTemplate LineObjectTemplate { get; set; }
public DataTemplate ModuleTemplate { get; set; }
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
if (item is CanvasObject)
return LineObjectTemplate;
if (item is Module)
return ModuleTemplate;
return base.SelectTemplate(item, container);
}
}
如果我将ModuleTemplates ItemsControl更改为ListBox，我至少可以看到在画布中的某个位置放置模块后左上角有一些选定的元素。我认为矩形容器可能没有大小，但我不确定如何正确处理。下降位置也没有效果。
可能它只是一个愚蠢的错误，就像透明的，不可丢弃的/隐藏的背景，今天花了我一个多小时，而且我看到＆＃34;＆＃34;经过几个小时的睡眠之后明天会有所帮助，但每一个帮助和提示都非常受欢迎！
问候
编辑：
THX到elgonzo我发现了错误。模块ItemsControl是不必要的！再次THX，现在是完成工作的最佳时间;）
以下代码正常工作：
<ItemsControl Grid.Column="1" Grid.Row="2" Margin="0" ItemsSource="{Binding CanvasObjects, UpdateSourceTrigger=PropertyChanged}">
<ItemsControl.Resources>
<ScaleTransform x:Key="LineTransform"
ScaleX="{Binding ActualWidth,
RelativeSource={RelativeSource AncestorType=ItemsControl}}"
ScaleY="{Binding ActualWidth,
RelativeSource={RelativeSource AncestorType=ItemsControl}}"/>
</ItemsControl.Resources>
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<Canvas Background="Transparent" AllowDrop="True" Drop="Canvas_OnDrop"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplateSelector>
<xmlTemp:TemplateSelector>
<xmlTemp:TemplateSelector.ModuleTemplate>
<DataTemplate DataType="{x:Type xmlElements:Module}">
<DataTemplate.Resources>
<Style TargetType="ContentPresenter">
<Setter Property="Canvas.Left" Value="{Binding AnchorPoint.X}"/>
<Setter Property="Canvas.Top" Value="{Binding AnchorPoint.Y}"/>
</Style>
</DataTemplate.Resources>
<Rectangle Width="{Binding Width}" Height="{Binding Height}" StrokeThickness="2" Fill="Black" Stroke="Black">
<Rectangle.RenderTransform>
<StaticResource ResourceKey="LineTransform"/>
</Rectangle.RenderTransform>
</Rectangle>
</DataTemplate>
</xmlTemp:TemplateSelector.ModuleTemplate>
<xmlTemp:TemplateSelector.LineObjectTemplate>
<DataTemplate DataType="{x:Type dt:CanvasObject}">
<ItemsControl ItemsSource="{Binding CanvasLines}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<Canvas/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<Path Stroke="{Binding Stroke}"
StrokeDashArray="{Binding StrokeDashArray}">
<Path.Data>
<LineGeometry
Transform="{StaticResource LineTransform}"
StartPoint="{Binding P1}"
EndPoint="{Binding P2}"/>
</Path.Data>
<Path.Style>
<Style TargetType="Path">
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="StrokeThickness">
<Setter.Value>
<MultiBinding Converter="{StaticResource MultiplicationConverter}">
<Binding Path="StrokeThickness" Mode="OneWay"/>
<Binding Source="3"/>
</MultiBinding>
</Setter.Value>
</Setter>
</Trigger>
<Trigger Property="IsMouseOver" Value="False">
<Setter Property="StrokeThickness" Value="{Binding StrokeThickness, Mode=OneWay}"/>
</Trigger>
</Style.Triggers>
</Style>
</Path.Style>
</Path>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</DataTemplate>
</xmlTemp:TemplateSelector.LineObjectTemplate>
</xmlTemp:TemplateSelector>
</ItemsControl.ItemTemplateSelector>
</ItemsControl>