动态创建 StackPanel 并在后面的代码中引用其中的任何一个

Question

以最简单的形式...

我想创建尽可能多的 StackPanel，然后在其中添加矩形。然后，例如，当我单击“开始”按钮时，能够更改任何一个矩形的填充颜色。一切都在代码隐藏中。

任何帮助，将不胜感激。

例如，如果我们最喜欢的啤酒编写了框架，我可以这样做：

XAML：

<Page
    x:Class="Test2.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Test2"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <Grid Background="White">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <StackPanel Orientation="Horizontal">
            <Button Name="StartButton" Content="Start" Click="StartButton_Click" Height="30" Width="200" Margin="5"/>
        </StackPanel>

        <StackPanel Grid.Row="1" Name="myStackPanel" VerticalAlignment="Top"/>

    </Grid>
</Page>

背后代码：

namespace Test2
{
    public sealed partial class MainPage : Page
    {
        public MainPage()
        {
            this.InitializeComponent();

            for (var i = 0; i < 5; i++) // The 5 here could be any number
            {
                myStackPanel.Children.Add(new StackPanel
                {
                    Name = "myPanel" + i,
                    Orientation = Orientation.Horizontal
                });

                for (var j = 0; j < 10; j++) // The 10 here could be any number
                {
                    ("myPanel" + i).Children.Add(new Rectangle
                    {
                        Name = "myRectangle" + i + "-" + j,
                        Fill = new SolidColorBrush(Colors.Black),
                        Width = 20,
                        Height = 20,
                        Margin = new Thickness(1)
                    });
                }
            }
        }

        private void StartButton_Click(object sender, RoutedEventArgs e)
        {
            // E.G. To change the Fill color of Rectangle4 in StackPanel2

            ("myRectangle" + 2 + "-" + 4).Fill = new SolidColorBrush(Colors.Red);
        }
    }
}

Answer 1

首先，要添加矩形形状，我们可以创建 StackPanel 的实例并操作其子元素：

for (var i = 0; i < 5; i++) // The 5 here could be any number
{
                StackPanel sp = new StackPanel
                {
                    Name = "myPanel" + i,
                    Orientation = Orientation.Horizontal
                };
                myStackPanel.Children.Add(sp);

                for (var j = 0; j < 10; j++) // The 10 here could be any number
                {
                    sp.Children.Add(new Rectangle
                    {
                        Name = "myRectangle" + i + "-" + j,
                        Fill = new SolidColorBrush(Colors.Black),
                        Width = 20,
                        Height = 20,
                        Margin = new Thickness(1)
                    });
                }
}

然后，例如，当我单击“开始”按钮时，能够更改任何一个矩形的填充颜色。一切都在代码隐藏中。

正如tgpdyk提到的，我们需要使用VisualTreeHelper来查找指定的矩形形状。

辅助类：

public static class FrameworkElementExtensions
{
        public static T TraverseCTFindShape<T>(DependencyObject root, String name) where T : Windows.UI.Xaml.Shapes.Shape
        {
            T control = null;

            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(root); i++)
            {
                var child = VisualTreeHelper.GetChild(root, i);

                string childName = child.GetValue(FrameworkElement.NameProperty) as string;
                control = child as T;

                if (childName == name)
                {
                    return control;
                }
                else
                {
                    control = TraverseCTFindShape<T>(child, name);

                    if (control != null)
                    {
                        return control;
                    }
                }
            }

            return control;
        }
}

如何使用它：

private void StartButton_Click(object sender, RoutedEventArgs e)
{
            // E.G. To change the Fill color of Rectangle4 in StackPanel2
            var rec = FrameworkElementExtensions.TraverseCTFindShape<Shape>(myStackPanel, "myRectangle" + 2 + "-" + 4);
            rec.Fill = new SolidColorBrush(Colors.Red);
}

我已将示例上传到Github 存储库