Windows Phone 7:如何像 XAML 一样解析 Bezier Path 字符串? [英] Windows Phone 7: How to parse Bezier Path string like in XAML?

问题描述

我需要解析贝塞尔路径字符串，但显然 .Net CF 框架中的 System.Windows.Media.Geometry 版本没有 Parse()code> 方法在它的正常对应物中可用.但是，输入以下 XAML 确实有效，因此系统必须有一种方法来解析路径数据字符串.

I have a need to parse Bezier Path Strings, but apparently the System.Windows.Media.Geometryversion in the .Net CF framework doesn't have the Parse() method that is available in it's normal counterpart. However, entering the following XAML does work, so there must be a way the system parses the Path Data String.

关于如何使用 XAML 之外的自定义字符串自行启动解析的任何线索?

Any clue on how I can initiate this parsing myself with a custom string outside XAML?

我当然也可以尝试使用正则表达式左右编写自己的解析器，但我不想自己处理这个，因为框架显然有能力.

I ofcourse could also try to write my own parser using regex or so, but I would prefer not to handle this myself, since the framework clearly is capable of it.

更新

当使用建议的 XAMLReader 时，当我为新创建的 Path 设置 StrokeThickness 时，我得到一个奇怪的异常:

When using the suggested XAMLReader, I get a strange Exception when I set a StrokeThickness to the newly created Path:

path.StrokeThickness = strokeWidth; //ArgumentException ??? (strokeWidth = 6)

当我使用手动解析器更改代码路径以进行渲染时，一切正常.我在这里错过了什么吗?除了解析器，没有任何变化.

When I change codepath to render using my manual parser, everything works correctly. Am I missing something here? Nothing changes except the parser.

手动生成数据:

        //"M {0} {1} Q {2} {3} {4} {5}"

        String regex_input = @"M (d+) (d+) Q (d+) (d+) (d+) (d+)";
        Regex regex = new Regex(regex_input);
        Match match = regex.Match(pathData);

        int startx = int.Parse(match.Groups[1].Value);
        int starty = int.Parse(match.Groups[2].Value);

        int controlx = int.Parse(match.Groups[3].Value);
        int controly = int.Parse(match.Groups[4].Value);

        int endx = int.Parse(match.Groups[5].Value);
        int endy = int.Parse(match.Groups[6].Value);

        PathGeometry geo = new PathGeometry();
        PathFigure figure = new PathFigure();
        figure.StartPoint = new Point(startx, starty);

        QuadraticBezierSegment quad = new QuadraticBezierSegment();
        quad.Point1 = new Point(controlx, controly);
        quad.Point2 = new Point(endx, endy);

        figure.Segments.Add(quad);

        geo.Figures.Add(figure);

        path.Data = geo;

使用 XamlReader

Using XamlReader

        String formattedXAMLInput = String.Format("<Path xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' Stroke='Black' Data='{0}'/>", pathData);
        Path xamlpath = (Path)XamlReader.Load(formattedXAMLInput);
        Geometry xamldata = xamlpath.Data;
        path.Data = xamldata;

推荐答案

我们目前没有公开路径迷你语言解析器的 API.它在 XAML 解析器内部.

We don't currently expose an API for the path mini-language parser. It's internal to the XAML parser.

但是，您可以使用 XamlReader 基于迷你语言字符串动态创建 Path 对象:

You can, however, create Path objects dynamically based on mini-language strings, using the XamlReader:

Path path = XamlReader.Load("<Path xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' Stroke='Blue' Data='M 0 0 Q 10 10 20 0'/>") as Path;

请注意，这实际上不会通过 API 向您公开几何的详细信息，但您可以在应用中显示生成的路径.

Note that this won't actually expose the details of the geometry through the API to you, but you can display the resulting Path in your app.

这篇关于Windows Phone 7:如何像 XAML 一样解析 Bezier Path 字符串?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！