Font Concepts字体概念

This section introduces you to the Font class, which supports the specification of detailed font information and the use of sophisticated typographic features.本节向您介绍Font类，该类支持详细字体信息的规范和复杂排版功能的使用。

A Font object represents an instance of a font face from the collection of font faces available on the system. Font对象表示系统上可用字体集合中的字体实例。Examples of common font faces include Helvetica Bold and Courier Bold Italic. 常见字体包括Helvetica粗体和Courier粗体斜体。Three names are associated with a Font object: its logical name, family name, and font face name:Font对象关联了三个名称：逻辑名称、字体系列名称和字体名称：

• A Font object's logical name is a name mapped onto a physical font, which is one of the specific fonts available on the system. Font对象的逻辑名称是映射到物理字体的名称，物理字体是系统上可用的特定字体之一。When specifying a Font in Java, use the font face name instead of the logical name. 在Java中指定Font时，请使用字体名称而不是逻辑名称。You can get the logical name from the Font by calling the getName method. 您可以通过调用getName方法从Font中获取逻辑名称。To get a list of the logical names that are mapped onto the specific fonts available on a system, call the java.awt.GraphicsEnvironment.getAvailableFontFamilyNames method.要获取映射到系统上可用的特定字体的逻辑名称列表，请调用java.awt.GraphicsEnvironment.getAvailableFontFamilyNames方法。

  See Physical and Logical Fonts for more information.有关详细信息，请参阅物理字体和逻辑字体。

• A Font object's family name is the name of the font family that determines the typographic design across several faces, such as Helvetica. Font对象的系列名称是字体族的名称，用于确定多个面（如Helvetica）的印刷设计。Retrieve the family name through the getFamily method.通过getFamily方法检索系列名称。

• A Font object's font face name refers to an actual font installed on a system. Font对象的字体名称是指安装在系统上的实际字体。This is the name you should use when specifying a font. 这是指定字体时应使用的名称。It's often referred to as just the font name. 它通常被称为字体名称。Retrieve the font name by calling getFontName. 通过调用getFontName检索字体名称。To determine which font faces are available on the system, call the java.awt.GraphicsEnvironment.getAllFonts method.要确定系统上可用的字体，请调用java.awt.GraphicsEnvironment.getAllFonts方法。

You can access information about a Font through the getAttributes method. 您可以通过getAttributes方法访问有关Font的信息。A Font object's attributes include its name, size, transform, and font features such as weight and posture.Font对象的属性包括其名称、大小、变换以及字体特征（如重量和姿势）。

A LineMetrics object encapsulates the measurement information associated with a Font, such as its ascent, descent, and leading:LineMetrics对象封装与字体相关联的度量信息，例如Font的上升、下降和前导：

• Ascent is the distance from the baseline to the ascender line. 上升是从基线到上升线的距离。This distance represents the typical height of capital letters, but some characters might extend above the ascender line.此距离表示大写字母的典型高度，但有些字符可能延伸到上升线以上。
• Descent is the distance from the baseline to the descender line. 下降是从基线到下降线的距离。The lowest point of most characters will fall within the descent, but some characters might extend below the descender line.大多数字符的最低点将落在下降线内，但有些字符可能延伸到下降线以下。
• Leading is the recommended distance from the bottom of the descender line to the top of the next line.前导是从下降线底部到下一行顶部的建议距离。

The following figure shows the position of the ascender line, baseline, and descender line:下图显示了上升线、基线和下降线的位置：

This information is used to properly position characters along a line, and to position lines relative to one another. 此信息用于沿一行正确定位字符，以及相对于另一行定位行。You can access these line metrics through the getAscent,  getDescent, and getLeading methods. 您可以通过getAscent、getDescent和getLeading方法访问这些行度量。You can also access information about a Font object's height, baseline, and underline and strikethrough characteristics through the LineMetrics class.您还可以通过LineMetrics类访问有关Font对象的高度、基线、下划线和删除线特征的信息。