Question

我有一个WPF项目，它在一个面板中绘制了几个东西。对于下一个版本，除了现有的东西之外，我还需要添加另一种类型的东西。目前我有一个包含ItemsControl的网格，其中包含ItemsPanel和ItemsSource。现有的ItemsSource看起来像这样：

                    <ItemsControl.ItemsSource>
                    <CompositeCollection>
                        <CollectionContainer
                                Collection="{Binding
                                    Source={StaticResource MainWindowResource},
                                    Path=DottedLines,
                                    Mode=OneWay}"/>
                        <CollectionContainer
                                Collection="{Binding
                                    Source={StaticResource MainWindowResource},
                                    Path=BarrierLines,
                                    Mode=OneWay}"/>
                        <CollectionContainer
                                Collection="{Binding
                                    Source={StaticResource MainWindowResource},
                                    Path=ProjectedLines,
                                    Mode=OneWay}"/>
                        <CollectionContainer
                                Collection="{Binding
                                    Source={StaticResource MainWindowResource},
                                    Path=ProjectedCranes,
                                    Mode=OneWay}"/>
                        <CollectionContainer
                                Collection="{Binding
                                    Source={StaticResource MainWindowResource},
                                    Path=CraneConfigs,
                                    Mode=OneWay}"/>
                        <CollectionContainer
                                Collection="{Binding
                                    Source={StaticResource MainWindowResource},
                                    Path=Sightlines,
                                    Mode=OneWay}"/>
                        <CollectionContainer
                                Collection="{Binding
                                    Source={StaticResource MainWindowResource},
                                    Path=CraneCenters,
                                    Mode=OneWay}"/>
                    </CompositeCollection>
                </ItemsControl.ItemsSource>

大多数集合都是线条或多边形。我定义了DataTemplates，用于将绘图对象的属性绑定到后备对象。 BarrierLine对象的示例如下所示：

        <DataTemplate DataType="{x:Type c:BarrierLineArt}">
        <Line
            X1="{Binding Path=AX}"
            Y1="{Binding Path=AY}"
            X2="{Binding Path=BX}"
            Y2="{Binding Path=BY}"
            Stroke="{Binding Path=LineColor}"
            StrokeThickness="{Binding Path=ScaledWeight}"
            StrokeEndLineCap="Round"
            StrokeStartLineCap="Round">
        </Line>
    </DataTemplate>

这一切都运作良好。现在我需要添加一系列要绘制的东西以及现有的东西。这个新东西有一系列线条以及平移和旋转值。不幸的是，我需要绘制这些新东西的集合。每个实例都有自己的转换和旋转以及行集合。实际上，我现在拥有一系列线条的集合。有没有办法嵌套CollectionContainers？我应该尝试将一个集合添加到DataTemplate吗？我不知道应该朝哪个方向前进。

修改

好的，我创建了一个概念验证程序，希望符合Peter的要求。我将在下面提供代码。它由五个文件组成： LineArt.cs ObstacleArt.cs MainWindowResource.cs MainWindow.xaml.cs MainWindow.xaml

LineArt对象表示绘制单行所需的数据。 ObstacleArt对象表示线的集合以及这些线的平移和旋转。我希望能够绘制一系列线条（没有任何转移或旋转）以及一系列障碍物，每个障碍物都有一系列线条。

我尝试使用Peter的建议将CompositeCollection放在CollectionContainer的Collection属性中，该CollectionContainer位于CompositeCollection中。你可以在靠近底部的xaml文件中看到它。

在Collection的Path属性中，当我放入“Obstacles [0] .Lines”时，它会画出第一个障碍的线条，但是当我取出索引并说“Obstacles.Lines”时它不会画任何东西。我需要的是能够绘制所有障碍物的所有线条。

除此之外，我还需要为每组线设置平移和旋转。

以下是文件，您应该能够编译并运行它。

LineArt.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Media;

namespace POC_WPF_nestedDrawingObjects
{
    public class LineArt : INotifyPropertyChanged
    {
        private Int32 _id = int.MinValue;
        private double _ax = 0;
        private double _ay = 0;
        private double _bx = 0;
        private double _by = 0;
        private SolidColorBrush _lineColor = Brushes.Black;
        private double _weight = 1;
        private double _scaledWeight = 1;

        public LineArt(
            Int32 id,
            double ax,
            double ay,
            double bx,
            double by,
            SolidColorBrush lineColor)
        {
            _id = id;
            _ax = ax;
            _ay = ay;
            _bx = bx;
            _by = by;
            _lineColor = lineColor;
            _weight = 1;
            _scaledWeight = _weight;
        }

        public Int32 Id { get { return _id; } }
        public double AX
        {
            get { return _ax; }
            set
            {
                _ax = value;
                SetPropertyChanged("AX");
            }
        }
        public double AY
        {
            get { return _ay; }
            set
            {
                _ay = value;
                SetPropertyChanged("AY");
            }
        }
        public double BX
        {
            get { return _bx; }
            set
            {
                _bx = value;
                SetPropertyChanged("BX");
            }
        }
        public double BY
        {
            get { return _by; }
            set
            {
                _by = value;
                SetPropertyChanged("BY");
            }
        }
        public SolidColorBrush LineColor
        {
            get { return _lineColor; }
            set
            {
                _lineColor = value;
                SetPropertyChanged("LineColor");
            }
        }
        public double Weight
        {
            get { return _weight; }
            set
            {
                _weight = value;
                SetPropertyChanged("Weight");
            }
        }
        public double ScaledWeight
        {
            get { return _scaledWeight; }
            set
            {
                _scaledWeight = value;
                SetPropertyChanged("ScaledWeight");
            }
        }

        #region INotifyPropertyChanged implementation

        public event PropertyChangedEventHandler PropertyChanged;
        private void SetPropertyChanged(string prop)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(
                    this,
                    new PropertyChangedEventArgs(prop));
            }
        }

        #endregion INotifyPropertyChanged implementation
    }
}

ObstacleArt.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace POC_WPF_nestedDrawingObjects
{
    public class ObstacleArt : INotifyPropertyChanged
    {
        private Int32 _id = int.MinValue;
        private ObservableCollection<LineArt> _lines
            = new ObservableCollection<LineArt>();
        private double _translateX = 0;
        private double _translateY = 0;
        private double _rotateAngle = 0;

        public ObstacleArt(
            Int32 id,
            double translateX,
            double translateY,
            double rotateAngle)
        {
            _id = id;
            _translateX = translateX;
            _translateY = translateY;
            _rotateAngle = rotateAngle;
        }

        public Int32 Id
        {
            get { return _id; }
        }
        public double TranslateX
        {
            get { return _translateX; }
            set
            {
                _translateX = value;
                SetPropertyChanged("TranslateX");
            }
        }
        public double TranslateY
        {
            get { return _translateX; }
            set
            {
                _translateX = value;
                SetPropertyChanged("TranslateX");
            }
        }
        public double RotateAngle
        {
            get { return _rotateAngle; }
            set
            {
                _rotateAngle = value;
                SetPropertyChanged("RotateAngle");
            }
        }
        public ObservableCollection<LineArt> Lines
        {
            get { return _lines; }
        }

        public void NotifyLinesChanged()
        {
            SetPropertyChanged("Lines");
        }

        public void LinesAddPropertyChangedHandlers()
        {
            foreach (LineArt line in _lines)
            {
                line.PropertyChanged += line_PropertyChanged;
            }
        }

        private void line_PropertyChanged(
            object sender,
            PropertyChangedEventArgs e)
        {
            SetPropertyChanged(e.PropertyName);
        }

        public void LinesDelPropertyChangedHandlers()
        {
            foreach (LineArt line in _lines)
            {
                line.PropertyChanged -= line_PropertyChanged;
            }
        }

        #region INotifyPropertyChanged implementation

        public event PropertyChangedEventHandler PropertyChanged;
        private void SetPropertyChanged(string prop)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(
                    this,
                    new PropertyChangedEventArgs(prop));
            }
        }

        #endregion INotifyPropertyChanged implementation
    }
}

MainWindowResource.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace POC_WPF_nestedDrawingObjects
{
    public class MainWindowResource : INotifyPropertyChanged
    {
        private ObservableCollection<LineArt> _lines
            = new ObservableCollection<LineArt>();
        private ObservableCollection<ObstacleArt> _obstacles
            = new ObservableCollection<ObstacleArt>();

        public ObservableCollection<LineArt> Lines
        {
            get
            {
                return _lines;
            }
        }

        public ObservableCollection<ObstacleArt> Obstacles
        {
            get
            {
                return _obstacles;
            }
        }

        public void NotifyLinesChanged()
        {
            SetPropertyChanged("Lines");
        }

        public void NotifyObstaclesChanged()
        {
            SetPropertyChanged("Obstacles");
        }

        public void LinesAddPropertyChangedHandlers()
        {
            foreach (LineArt line in _lines)
            {
                line.PropertyChanged += line_PropertyChanged;
            }
        }

        public void LinesDelPropertyChangedHandlers()
        {
            foreach (LineArt line in _lines)
            {
                line.PropertyChanged -= line_PropertyChanged;
            }
        }

        private void line_PropertyChanged(
            object sender,
            PropertyChangedEventArgs e)
        {
            SetPropertyChanged(e.PropertyName);
        }

        #region INotifyPropertyChanged implementation

        public event PropertyChangedEventHandler PropertyChanged;
        private void SetPropertyChanged(string prop)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(
                    this,
                    new PropertyChangedEventArgs(prop));
            }
        }

        #endregion INotifyPropertyChanged implementation
    }
}

MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace POC_WPF_nestedDrawingObjects
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        private MainWindowResource _mainWindowResource = null;
        private SolidColorBrush _brush
            = new SolidColorBrush(Color.FromArgb(255, 0, 0, 0));

        public MainWindow()
        {
            LineArt line = null;
            ObstacleArt obstacle = null;

            InitializeComponent();

            Application app = Application.Current;
            _mainWindowResource
                = (MainWindowResource)this.Resources["MainWindowResource"];

            // initialize four lines, they will form a rectangle
            _mainWindowResource.LinesDelPropertyChangedHandlers();
            line = new LineArt(1, 10, 10, 30, 10, _brush);
            _mainWindowResource.Lines.Add(line);
            line = new LineArt(2, 30, 10, 30, 20, _brush);
            _mainWindowResource.Lines.Add(line);
            line = new LineArt(2, 30, 20, 10, 20, _brush);
            _mainWindowResource.Lines.Add(line);
            line = new LineArt(2, 10, 20, 10, 10, _brush);
            _mainWindowResource.Lines.Add(line);
            _mainWindowResource.LinesAddPropertyChangedHandlers();
            _mainWindowResource.NotifyLinesChanged();

            // initialize an obstacle made of four lines.
            // the lines form a 20x20 square around 0,0.
            // the obstacle should be trastlated to 50,50
            // and not rotated
            obstacle = new ObstacleArt(1, 50, 50, 0);
            obstacle.LinesDelPropertyChangedHandlers();
            line = new LineArt(1, -10, 10, 10, 10, _brush);
            obstacle.Lines.Add(line);
            line = new LineArt(2, 10, 10, 10, -10, _brush);
            obstacle.Lines.Add(line);
            line = new LineArt(3, 10, -10, -10, -10, _brush);
            obstacle.Lines.Add(line);
            line = new LineArt(4, -10, -10, -10, 10, _brush);
            obstacle.Lines.Add(line);
            obstacle.LinesAddPropertyChangedHandlers();
            _mainWindowResource.Obstacles.Add(obstacle);

            // initialize an obstacle made of four lines.
            // the lines form a 20x20 square around 0,0.
            // the obstacle should be trastlated to 100,100
            // and rotated to a 45 degree angle
            obstacle = new ObstacleArt(1, 100, 100, 45);
            obstacle.LinesDelPropertyChangedHandlers();
            line = new LineArt(1, -10, 10, 10, 10, _brush);
            obstacle.Lines.Add(line);
            line = new LineArt(2, 10, 10, 10, -10, _brush);
            obstacle.Lines.Add(line);
            line = new LineArt(3, 10, -10, -10, -10, _brush);
            obstacle.Lines.Add(line);
            line = new LineArt(4, -10, -10, -10, 10, _brush);
            obstacle.Lines.Add(line);
            obstacle.LinesAddPropertyChangedHandlers();
            _mainWindowResource.Obstacles.Add(obstacle);

            _mainWindowResource.NotifyObstaclesChanged();
            _mainWindowResource.NotifyLinesChanged();
            foreach(ObstacleArt obstacleArt in _mainWindowResource.Obstacles)
            {
                obstacleArt.NotifyLinesChanged();
            }
        }
    }
}

MainWindow.xaml

<Window x:Class="POC_WPF_nestedDrawingObjects.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:c="clr-namespace:POC_WPF_nestedDrawingObjects"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <c:MainWindowResource x:Key="MainWindowResource"/>
        <DataTemplate DataType="{x:Type c:LineArt}">
            <Line
                X1="{Binding Path=AX}"
                Y1="{Binding Path=AY}"
                X2="{Binding Path=BX}"
                Y2="{Binding Path=BY}"
                Stroke="{Binding Path=LineColor}"
                StrokeThickness="{Binding Path=ScaledWeight}"
                StrokeEndLineCap="Round"
                StrokeStartLineCap="Round">
            </Line>
        </DataTemplate>
        <Style x:Key="ContentCanvasStyle" TargetType="Canvas">
            <Setter Property="RenderTransformOrigin" Value="0,0"/>
        </Style>
    </Window.Resources>
    <Grid>
        <ItemsControl>
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                    <Canvas x:Name="ContentCanvas"
                        Style="{StaticResource ContentCanvasStyle}">
                    </Canvas>
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
            <ItemsControl.ItemsSource>
                <CompositeCollection>
                    <CollectionContainer
                        Collection="{Binding
                            Source={StaticResource MainWindowResource},
                            Path=Lines,
                            Mode=OneWay}"/>
                    <CollectionContainer>
                        <CollectionContainer.Collection>
                        <CompositeCollection>
                            <CollectionContainer
                                Collection="{Binding
                                    Source={StaticResource MainWindowResource},
                                    Path=Obstacles[0].Lines,
                                    Mode=OneWay}"/>
                            </CompositeCollection>
                        </CollectionContainer.Collection>
                    </CollectionContainer>
                </CompositeCollection>
            </ItemsControl.ItemsSource>
        </ItemsControl>
    </Grid>
</Window>

Answer 1

感谢您提供改进的代码示例。从那以后，在我看来，你完全以错误的方式实现目标。

也就是说，您尝试使用单个ItemsControl对象渲染所有行。但这并不是您的数据模型的组织方式。您的数据模型有两种完全不同的对象：LineArt个对象，以及包含ObstacleArt个对象的LineArt对象。

鉴于此，在我看来，更合适的方法是简单地组合MainWindowResource.Lines和MainWindowResource.Obstacles集合，然后使用数据模板来适当地显示这些集合。

以下是XAML的新版本，显示了我的意思：

<Window x:Class="POC_WPF_nestedDrawingObjects.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:c="clr-namespace:POC_WPF_nestedDrawingObjects"
        Title="MainWindow" Height="350" Width="525">

  <Window.Resources>
    <c:MainWindowResource x:Key="MainWindowResource"/>
    <Style x:Key="ContentCanvasStyle" TargetType="Canvas">
      <Setter Property="RenderTransformOrigin" Value="0,0"/>
    </Style>
    <DataTemplate DataType="{x:Type c:LineArt}">
      <Line
                X1="{Binding Path=AX}"
                Y1="{Binding Path=AY}"
                X2="{Binding Path=BX}"
                Y2="{Binding Path=BY}"
                Stroke="{Binding Path=LineColor}"
                StrokeThickness="{Binding Path=ScaledWeight}"
                StrokeEndLineCap="Round"
                StrokeStartLineCap="Round">
      </Line>
    </DataTemplate>
    <DataTemplate DataType="{x:Type c:ObstacleArt}">
      <ItemsControl ItemsSource="{Binding Lines, Mode=OneWay}">
        <ItemsControl.ItemsPanel>
          <ItemsPanelTemplate>
            <Canvas x:Name="ContentCanvas"
                        Style="{StaticResource ContentCanvasStyle}">
            </Canvas>
          </ItemsPanelTemplate>
        </ItemsControl.ItemsPanel>
        <ItemsControl.RenderTransform>
          <TransformGroup>
            <RotateTransform Angle="{Binding RotateAngle}"/>
            <TranslateTransform X="{Binding TranslateX}" Y="{Binding TranslateY}"/>
          </TransformGroup>
        </ItemsControl.RenderTransform>
      </ItemsControl>
    </DataTemplate>
  </Window.Resources>
  <Grid>
    <ItemsControl>
      <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
          <Canvas x:Name="ContentCanvas"
                  Style="{StaticResource ContentCanvasStyle}">
          </Canvas>
        </ItemsPanelTemplate>
      </ItemsControl.ItemsPanel>
      <ItemsControl.ItemsSource>
        <CompositeCollection>
          <CollectionContainer
              Collection="{Binding
                  Source={StaticResource MainWindowResource},
                  Path=Lines,
                  Mode=OneWay}"/>
          <CollectionContainer
              Collection="{Binding
                  Source={StaticResource MainWindowResource},
                  Path=Obstacles,
                  Mode=OneWay}"/>
        </CompositeCollection>
      </ItemsControl.ItemsSource>
    </ItemsControl>
  </Grid>
</Window>

此处的关键是第二个DataTemplate，其目标类型为ObstacleArt。这允许主ItemsControl显示复合集合中的各个ObstacleArt元素。通过第二个数据模板，它通过在每个ItemsControl对象中嵌套一个全新的ObstacleArt来实现，其中ItemsControl处理ObstacleArt对象的所有渲染。请注意，由于该嵌套ItemsControl对象中的实际项本身就是LineArt项，因此最终会引用DataTemplate LineArt类型。

以上工作对您的代码隐藏完全没有任何改变。也就是说，我认为你最好让你的类继承DependencyObject，然后创建可绑定属性依赖属性。 WPF当然支持INotifyPropertyChanged，但是如果你使用了依赖属性范例，那么你有很多明确的属性通知代码就会消失。

在WPF中我需要有一组绘图对象的集合

1 个答案: