介紹一下我最近開發(fā)的一個Flutter插件。Flutter Math是一個完全使用Dart和Flutter渲染LaTeX數(shù)學公式的插件，可以看作是移植在Dart和Flutter平臺上的KaTeX。其支持的LaTeX語法大致與KaTeX相同（少數(shù)當前版本暫不支持的語法詳見Github倉庫），對數(shù)學公式的渲染結果幾乎像素級還原KaTeX。

相比已有的flutter_tex插件，本插件完全的基于Dart和Flutter，不包含任何WebView和Javascript，性能遠超過flutter_tex。大家如果頻繁遇到flutter_tex帶來的卡頓以及崩潰，歡迎試用Flutter Math。

渲染樣例

x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}

二次方程根

i\hbar\frac{\partial}{\partial t}\Psi(\vec x,t) = -\frac{\hbar}{2m}\nabla^2\Psi(\vec x,t)+ V(\vec x)\Psi(\vec x,t)

薛定諤方程

\hat f(\xi) = \int_{-\infty}^\infty f(x)e^{- 2\pi i \xi x}\mathrmu0z1t8osx

傅里葉變換

使用方法

1. 在pubspec.yaml文件中添加對flutter_math的依賴
2. 在pubspec.yaml的flutter: 標簽下加入下列字體資源

   flutter:
   
     // ......
   
     fonts:
       - family: KaTeX_Main
         fonts:
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Main-Regular.ttf
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Main-Italic.ttf
             style: italic
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Main-Bold.ttf
             weight: 700
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Main-BoldItalic.ttf
             weight: 700
             style: italic
       - family: KaTeX_Math
         fonts:
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Math-Italic.ttf
             style: italic
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Math-BoldItalic.ttf
             weight: 700
             style: italic
       - family: KaTeX_AMS
         fonts:
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_AMS-Regular.ttf
       - family: KaTeX_Caligraphic
         fonts:
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Caligraphic-Regular.ttf
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Caligraphic-Bold.ttf
             weight: 700
       - family: KaTeX_Fraktur
         fonts:
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Fraktur-Regular.ttf
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Fraktur-Bold.ttf
             weight: 700
       - family: KaTeX_SansSerif
         fonts:
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_SansSerif-Regular.ttf
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_SansSerif-Bold.ttf
             weight: 700
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_SansSerif-Italic.ttf
             style: italic
       - family: KaTeX_Script
         fonts:
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Script-Regular.ttf
       - family: KaTeX_Typewriter
         fonts:
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Typewriter-Regular.ttf
       - family: KaTeX_Size1
         fonts:
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Size1-Regular.ttf
       - family: KaTeX_Size2
         fonts:
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Size2-Regular.ttf
       - family: KaTeX_Size3
         fonts:
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Size3-Regular.ttf
       - family: KaTeX_Size4
         fonts:
           - asset: packages/flutter_math/katex_fonts/fonts/KaTeX_Size4-Regular.ttf
   

3. 在代碼中使用FlutterMath.fromTexString(expression)組件展示渲染結果?？梢酝ㄟ^提供可選參數(shù)options控制渲染樣式，baseSizeMultiplier控制大小，onErrorFallback自定義輸入錯誤時如何展示報錯信息。樣例如下

   FlutterMath.fromTexString(
     r'\frac a b',
     options: Options.displayOptions,
     baseSizeMultiplier: 1.0
     onErrorFallback: (errMsg) => Text(errMsg),
   )
   

項目倉庫地址：GitHub地址。目前版本為0.1.1，更多信息以及暫不支持的KaTeX特性歡迎查閱GitHub頁面。歡迎打星，歡迎fork！