生成动画线

Question

(x,y) =(10,20),(50,30),(20,20),(40,22),(45,20),(50,35),.........

我想使用.Net创建一个动画，通常我会使用windows form。但如果需要，我也可以使用WPF。

它从(10,20)点开始。实际上，一条线从(10,20)开始，然后在10毫秒的延迟后到达(50,30)点。然后，从(50,30)到(20,20)，再过10毫秒，以此类推。

这些值将从文本文件中读取。我可以简单地制作两个ArrayList x和y，把值从文本文件中放入其中。我只需要知道如何从这个x，y生成带有每个节点到另一个节点10ms延迟的动态线？

如果我的问题难以理解，请告诉我。我会尽力让它变得更容易理解。

提前感谢。

- Abdur Rahim

Answer 1

如果我理解您的意思正确，您想要将线条动画显示为刚刚被绘制出来的样子。以下是一个使用您提供的数值的简单示例。

<Window x:Class="WpfApplication1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">

    <Canvas Name="lineCanvas" MouseLeftButtonDown="lineCanvas_MouseLeftButtonDown" Background="White" />
</Window>

事件处理程序稍后将启动动画。首先，我们将定义数据：

List<Point> Points = new List<Point>();
Storyboard sb;

public MainWindow()
{
    InitializeComponent();

    Points.Add(new Point(10, 20));
    Points.Add(new Point(50, 30));
    Points.Add(new Point(20, 20));
    Points.Add(new Point(40, 22));
    Points.Add(new Point(45, 20));
    Points.Add(new Point(50, 35));

    InitAnimation();
}

sb 是包含动画的 Storyboard。可以轻松地从文件中填充 Points 的值。

让我们初始化动画。每个线段都会添加一行新的内容。然后，线段的终点将被动画化。

public void InitAnimation()
{
    sb = new Storyboard();

    for (int i = 0; i < Points.Count - 1; ++i)
    {
        //new line for current line segment
        var l = new Line();
        l.Stroke = Brushes.Black;
        l.StrokeThickness = 2;

        //data from list
        var startPoint = Points[i];
        var endPoint = Points[i + 1];

        //set startpoint = endpoint will result in the line not being drawn
        l.X1 = startPoint.X;
        l.Y1 = startPoint.Y;
        l.X2 = startPoint.X;
        l.Y2 = startPoint.Y;
        lineCanvas.Children.Add(l);

        //Initialize the animations with duration of 1 second for each segment
        var daX = new DoubleAnimation(endPoint.X, new Duration(TimeSpan.FromMilliseconds(1000)));
        var daY = new DoubleAnimation(endPoint.Y, new Duration(TimeSpan.FromMilliseconds(1000)));
        //Define the begin time. This is sum of durations of earlier animations + 10 ms delay for each
        daX.BeginTime = TimeSpan.FromMilliseconds(i * 1010);
        daY.BeginTime = TimeSpan.FromMilliseconds(i * 1010);

        sb.Children.Add(daX);
        sb.Children.Add(daY);

        //Set the targets for the animations
        Storyboard.SetTarget(daX, l);
        Storyboard.SetTarget(daY, l);
        Storyboard.SetTargetProperty(daX, new PropertyPath(Line.X2Property));
        Storyboard.SetTargetProperty(daY, new PropertyPath(Line.Y2Property));
    }
}

动画的持续时间可以根据线条的长度轻松更改，使其看起来更加美观。

最后一个任务，展示动画：

private void lineCanvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    sb.Begin(this);
}

- Nico Schertler

---

谢谢Nico。它完美地运行了。顺便说一下，你理解我的意思了 :) - Abdur Rahim

Answer 2

这是对Nico伟大答案的改进。我使用PointAnimation来动画化LineGeometry的EndPoint，该LineGeometry作为Path的Data。

using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace SoGeneratingAnimatedLine
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            var canvas = new Canvas();

            Content = canvas;

            var points =
                new List<Point>()
                {
                    new Point(10, 10),
                    new Point(90, 10),
                    new Point(90, 90),
                    new Point(10, 90),
                    new Point(10, 10)
                };

            var sb = new Storyboard();

            for (int i = 0; i < points.Count - 1; i++)
            {
                var lineGeometry = new LineGeometry(points[i], points[i]);

                var path =
                    new Path()
                    {
                        Stroke = Brushes.Black,
                        StrokeThickness = 2,
                        Data = lineGeometry
                    };

                canvas.Children.Add(path);

                var animation =
                    new PointAnimation(points[i], points[i + 1], new Duration(TimeSpan.FromMilliseconds(1000)))
                    {
                        BeginTime = TimeSpan.FromMilliseconds(i * 1010)
                    };

                sb.Children.Add(animation);

                RegisterName("geometry" + i, lineGeometry);
                Storyboard.SetTargetName(animation, "geometry" + i);
                Storyboard.SetTargetProperty(animation, new PropertyPath(LineGeometry.EndPointProperty));                
            }

            MouseDown += (s, e) => sb.Begin(this);
        }
    }
}

- dharmatech