# 數學文字

> 探索 Aspose.Slides for C++ 的 MathematicalText 範例：使用 C++ 在 PPT、PPTX 與 ODP 投影片中建立與格式化方程式、分數、矩陣與符號。

Source: https://docs.aspose.com/slides/zh-hant/cpp/examples/elements/math-text/


本文示範如何使用 **Aspose.Slides for C++** 處理數學文字形狀並格式化方程式。

## **新增數學文字**
建立一個包含分數和畢氏定理公式的數學形狀。

```cpp
static void AddMathText()
{
    auto presentation = MakeObject<Presentation>();
    auto slide = presentation->get_Slide(0);

    // 將數學形狀新增至投影片。
    auto mathShape = slide->get_Shapes()->AddMathShape(0, 0, 720, 150);

    // 存取數學段落。
    auto paragraph = mathShape->get_TextFrame()->get_Paragraph(0);
    auto textPortion = paragraph->get_Portion(0);
    auto mathParagraph = ExplicitCast<MathPortion>(textPortion)->get_MathParagraph();

    // 新增簡單分數：x / y。
    auto fraction = MakeObject<MathematicalText>(u"x")->Divide(u"y");
    mathParagraph->Add(MakeObject<MathBlock>(fraction));

    // 新增方程式：c² = a² + b²。
    auto mathBlock = MakeObject<MathematicalText>(u"c")
        - >SetSuperscript(u"2")
        - >Join(u"=")
        - >Join(MakeObject<MathematicalText>(u"a")->SetSuperscript(u"2"))
        - >Join(u"+")
        - >Join(MakeObject<MathematicalText>(u"b")->SetSuperscript(u"2"));
    mathParagraph->Add(mathBlock);

    presentation->Dispose();
}
```

## **存取數學文字**
在投影片中找到包含數學段落的形狀。

```cpp
static void AccessMathText()
{
    auto presentation = MakeObject<Presentation>(u"sample.pptx");
    auto slide = presentation->get_Slide(0);

    // 尋找第一個包含數學段落的形狀。
    auto mathShape = SharedPtr<IAutoShape>();
    for (auto&& shape : slide->get_Shapes())
    {
        if (ObjectExt::Is<IAutoShape>(shape))
        {
            auto autoShape = ExplicitCast<IAutoShape>(shape);
            auto textFrame = autoShape->get_TextFrame();
            auto hasMath = false;
            for (auto&& paragraph : textFrame->get_Paragraphs())
            {
                for (auto&& textPortion : paragraph->get_Portions())
                {
                    if (ObjectExt::Is<MathPortion>(textPortion))
                    {
                        hasMath = true;
                        break;
                    }
                }
                if (hasMath) break;
            }
            if (hasMath)
            {
                mathShape = autoShape;
                break;
            }
        }
    }

    if (mathShape != nullptr)
    {
        auto paragraph = mathShape->get_TextFrame()->get_Paragraph(0);
        auto textPortion = paragraph->get_Portion(0);
        auto mathParagraph = ExplicitCast<MathPortion>(textPortion)->get_MathParagraph();

        // 範例：建立分數（此處未加入）。
        auto fraction = MakeObject<MathematicalText>(u"x")->Divide(u"y");

        // Use mathParagraph or fraction as needed...
    }

    presentation->Dispose();
}
```

## **移除數學文字**
從投影片中刪除數學形狀。

```cpp
static void RemoveMathText()
{
    auto presentation = MakeObject<Presentation>();
    auto slide = presentation->get_Slide(0);

    auto mathShape = slide->get_Shapes()->AddMathShape(50, 50, 100, 50);

    auto paragraph = mathShape->get_TextFrame()->get_Paragraph(0);
    auto textPortion = paragraph->get_Portion(0);
    auto mathParagraph = ExplicitCast<MathPortion>(textPortion)->get_MathParagraph();
    auto fraction = MakeObject<MathematicalText>(u"x")->Divide(u"y");
    mathParagraph->Add(MakeObject<MathBlock>(fraction));

    // 移除數學形狀。
    slide->get_Shapes()->Remove(mathShape);

    presentation->Dispose();
}
```

## **格式化數學文字**
設定數學部分的字型屬性。

```cpp
static void FormatMathText()
{
    auto presentation = MakeObject<Presentation>();
    auto slide = presentation->get_Slide(0);

    auto mathShape = slide->get_Shapes()->AddMathShape(50, 50, 100, 50);
    auto paragraph = mathShape->get_TextFrame()->get_Paragraph(0);
    auto textPortion = paragraph->get_Portion(0);
    auto mathParagraph = ExplicitCast<MathPortion>(textPortion)->get_MathParagraph();
    auto fraction = MakeObject<MathematicalText>(u"x")->Divide(u"y");
    mathParagraph->Add(MakeObject<MathBlock>(fraction));

    textPortion->get_PortionFormat()->set_FontHeight(20);

    presentation->Dispose();
}
```