创建列表视图时将形状信息添加到列表视图

小编典典

创建列表视图时将形状信息添加到列表视图

我在画布上创建形状（矩形，椭圆形，直线）。然后我在另一个窗口中有一个列表视图，我需要在其中输入形状信息（例如位置，大小，它是什么形状）。

我在另一个窗口的XAML中有以下代码：

    <ListView Name="Information">

        <ListView.View>
            <GridView>
                <GridViewColumn Header="Type"/>
                <GridViewColumn Header="PositionX"/>
                <GridViewColumn Header="PositionY"/>
                <GridViewColumn Header="Width" DisplayMemberBinding="{Binding ActualWidth}"/>
                <GridViewColumn Header="Height" DisplayMemberBinding="{Binding ActualHeight}"/>
            </GridView>
        </ListView.View>

    </ListView>

在主窗口的C＃中，我有一个可观察的集合和以下代码：

ObservableCollection<Shape> shapes = new ObservableCollection<Shape>();

myRect.Width = var1;
myRect.Height = var2;
Page.Children.Add(myRect);
Canvas.SetLeft(myRect, posx);
Canvas.SetTop(myRect, posy);

shapes.Add(myRect);
2ndwindow.Information.ItemsSource = shapes; // this is working because the 2ndwindow is owned by the mainwindow

编辑：我设法绑定宽度和高度，但我不知道如何绑定位置和它的形状（矩形或椭圆形）

阅读 432

2020-05-19

共1个答案

小编典典

在适当的MVVM方法中，您应该具有一个带有Shape的抽象表示的视图模型（而不是UI元素列表），例如：

public class ShapeData
{
    public string Type { get; set; }
    public Geometry Geometry { get; set; }
    public Brush Fill { get; set; }
    public Brush Stroke { get; set; }
    public double StrokeThickness { get; set; }
}

public class ViewModel
{
    public ObservableCollection<ShapeData> Shapes { get; }
        = new ObservableCollection<ShapeData>();
}

您现在可以将此视图模型绑定到如下所示的视图。从形状对象的Bounds属性中检索每个形状的位置和大小Geometry。

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition/>
        <ColumnDefinition/>
    </Grid.ColumnDefinitions>

    <ItemsControl ItemsSource="{Binding Shapes}">
        <ItemsControl.ItemsPanel>
            <ItemsPanelTemplate>
                <Canvas/>
            </ItemsPanelTemplate>
        </ItemsControl.ItemsPanel>
        <ItemsControl.ItemTemplate>
            <DataTemplate>
                <Path Data="{Binding Geometry}"
                      Fill="{Binding Fill}"
                      Stroke="{Binding Stroke}"
                      StrokeThickness="{Binding StrokeThickness}"/>
            </DataTemplate>
        </ItemsControl.ItemTemplate>
    </ItemsControl>

    <ListView Grid.Column="1" ItemsSource="{Binding Shapes}">
        <ListView.View>
            <GridView>
                <GridViewColumn Header="Type"
                                DisplayMemberBinding="{Binding Type}"/>
                <GridViewColumn Header="X"
                                DisplayMemberBinding="{Binding Geometry.Bounds.X}"/>
                <GridViewColumn Header="Y"
                                DisplayMemberBinding="{Binding Geometry.Bounds.Y}"/>
                <GridViewColumn Header="Width" 
                                DisplayMemberBinding="{Binding Geometry.Bounds.Width}"/>
                <GridViewColumn Header="Height"
                                DisplayMemberBinding="{Binding Geometry.Bounds.Height}"/>
            </GridView>
        </ListView.View>
    </ListView>
</Grid>

您可以在窗口的构造函数中创建一个视图模型实例，并添加一些示例数据，如下所示：

public MainWindow()
{
    InitializeComponent();

    var viewModel = new ViewModel();

    viewModel.Shapes.Add(new ShapeData
    {
        Type = "Circle",
        Geometry = new EllipseGeometry(new Point(100, 100), 50, 50),
        Fill = Brushes.Orange,
        Stroke = Brushes.Navy,
        StrokeThickness = 2
    });

    viewModel.Shapes.Add(new ShapeData
    {
        Type = "Rectangle",
        Geometry = new RectangleGeometry(new Rect(200, 50, 50, 100)),
        Fill = Brushes.Yellow,
        Stroke = Brushes.DarkGreen,
        StrokeThickness = 2
    });

    DataContext = viewModel;
}

2020-05-19