使用 C# 和 WPF 在代码中绘制线条

Question

我正在尝试使用 7 段显示器创建数字时钟显示器。我可以使用如下代码在 XAML 中绘制线条：

<Line Name="line7" Stroke="Black" StrokeThickness="4" X1="10" X2="40" Y1="70" Y2="70" Margin="101,-11,362,250" />

但是当我尝试在代码中执行此操作（来自 MainWindow（））时，它不起作用：

        Line line = new Line();
        Thickness thickness = new Thickness(101,-11,362,250);
        line.Margin = thickness;
        line.Visibility = System.Windows.Visibility.Visible;
        line.StrokeThickness = 4;
        line.Stroke = System.Windows.Media.Brushes.Black;
        line.X1 = 10;
        line.X2 = 40;
        line.Y1 = 70;
        line.Y2 = 70;

这个想法是我可以画 7 条线，然后根据需要为不同的数字切换它们的可见性。我相信这可以通过多种方式完成，但是为什么我不能像这样在代码中画线呢？

Answer 1

这是你的整个绘图代码吗？如果是这样，则需要将line对象添加到曲面。例如，如果您使用的是全屏广告：

myCanvas.Children.Add(line);

这会将您的线条添加到画布中。目前，您只是在创建线条，而不是将其放在任何地方。

您可以在此 MSDN 页面上找到有关在 WPF 中绘制的详细信息。

Answer 2

public class Cls_Barriere
{
    // animazione periferica
    public static void LineAnimation(Line _line,String _colore)
    {
        Storyboard result = new Storyboard();
        Duration duration = new Duration(TimeSpan.FromSeconds(2));
        ColorAnimation animation = new ColorAnimation();
        animation.RepeatBehavior = RepeatBehavior.Forever;
        animation.Duration = duration;
        switch (_colore.ToUpper())
        {
            case "RED": 
                animation.From = Colors.Red;
                break;
            case "ORANGE": 
                animation.From = Colors.Orange;
                break;
            case "YELLOW": 
                animation.From = Colors.Yellow;
                break;
            case "GRAY": 
                animation.From = Colors.DarkGray;
                break;
            default: 
                animation.From = Colors.Green;
                break;
        }
        animation.To = Colors.Gray;
        Storyboard.SetTarget(animation, _line);
        Storyboard.SetTargetProperty(animation, new PropertyPath("(Line.Stroke).(SolidColorBrush.Color)"));
        result.Children.Add(animation);
        result.Begin();
    }
}
//***************************************************************************  
public partial class MainPage : UserControl
{
    public Line _line;
    public MainPage()
    {
        InitializeComponent();
        Canvas.MouseLeftButtonDown += Canvas_MouseLeftButtonDown;
        Canvas.MouseLeftButtonUp += Canvas_MouseLeftButtonUp;
    }
    void Canvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
    {
        _line.X2 = e.GetPosition(this.Canvas).X;
        _line.Y2 = e.GetPosition(this.Canvas).Y;
        _line.Loaded += _line_Loaded;
        Canvas.Children.Add(_line);
    }
    void _line_Loaded(object sender, RoutedEventArgs e)
    {
        Cls_Barriere.LineAnimation(sender as Line, "RED");
    }
    void Canvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        _line = new Line();
        _line.Stroke = new SolidColorBrush(Colors.White);
        _line.StrokeThickness = 5;
        _line.StrokeStartLineCap = PenLineCap.Round; 
        _line.StrokeEndLineCap = PenLineCap.Round;
        _line.StrokeDashCap = PenLineCap.Round;
        _line.X1 = e.GetPosition(this.Canvas).X;
        _line.Y1= e.GetPosition(this.Canvas).Y;
    }