const TextStyle({
    this.inherit: true,         // 为false的时候不显示
    this.color,                    // 颜色 
    this.fontSize,               // 字号
    this.fontWeight,           // 字重，加粗也用这个字段  FontWeight.w700
    this.fontStyle,                // FontStyle.normal  FontStyle.italic斜体
    this.letterSpacing,        // 字符间距  就是单个字母或者汉字之间的间隔，可以是负数
    this.wordSpacing,        // 字间距 句字之间的间距
    this.textBaseline,        // 基线，两个值，字面意思是一个用来排字母的，一人用来排表意字的（类似中文）
    this.height,                // 当用来Text控件上时，行高（会乘以fontSize,所以不以设置过大）
    this.decoration,        // 添加上划线，下划线，删除线 
    this.decorationColor,    // 划线的颜色
    this.decorationStyle,    // 这个style可能控制画实线，虚线，两条线，点, 波浪线等
    this.debugLabel,
    String fontFamily,    // 字体
    String package,
  }) : fontFamily = package == null ? fontFamily : 'packages/$package/$fontFamily',
       assert(inherit != null);

import 'package:flutter/material.dart';

/**
 * TextStyle Demo页面
 */
class TextStylePage extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return new TextStyleState();
  }
}

class TextStyleState extends State<TextStylePage> {
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
        appBar: new AppBar(
          // 去掉导航栏下面的阴影
          elevation: 0.0,
          title: new Text('TextStyle'),
        ),
        body: new Container(
          margin: EdgeInsets.all(10.0),
          child: new Column(
            crossAxisAlignment: CrossAxisAlignment.center,
            children: <Widget>[
              new Text(
                'inherit: 为 false 的时候不显示',
                style: new TextStyle(
                  inherit: true,
                ),
              ),
              new Text(
                'color/fontSize: 字体颜色，字号等',
                style: new TextStyle(
                  color: Color.fromARGB(255, 150, 150, 150),
                  fontSize: 22.0,
                ),
              ),
              new Text(
                'fontWeight: 字重',
                style: new TextStyle(fontWeight: FontWeight.w700),
              ),
              new Text(
                'fontStyle: FontStyle.italic 斜体',
                style: new TextStyle(
                  fontStyle: FontStyle.italic,
                ),
              ),
              new Text(
                'letterSpacing: 字符间距',
                style: new TextStyle(
                  letterSpacing: 10.0,
                  // wordSpacing: 15.0
                ),
              ),
              new Text(
                'wordSpacing: 字或单词间距',
                style: new TextStyle(
                    // letterSpacing: 10.0,
                    wordSpacing: 15.0),
              ),
              new Text(
                'textBaseline:这一行的值为TextBaseline.alphabetic',
                style: new TextStyle(
                    textBaseline: TextBaseline.alphabetic),
              ),
              new Text(
                'textBaseline:这一行的值为TextBaseline.ideographic',
                style: new TextStyle(
                    textBaseline: TextBaseline.ideographic),
              ),
              new Text(
                'height: 用在Text控件上的时候，会乘以fontSize做为行高,所以这个值不能设置过大',
                style: new TextStyle(
                  height: 1.0,
                )
              ),
              new Text(
                'decoration: TextDecoration.overline 上划线',
                style: new TextStyle(
                  decoration: TextDecoration.overline,
                  decorationStyle: TextDecorationStyle.wavy
                )
              ),
              new Text(
                'decoration: TextDecoration.lineThrough 删除线',
                style: new TextStyle(
                  decoration: TextDecoration.lineThrough,
                  decorationStyle: TextDecorationStyle.dashed
                )
              ),
              new Text(
                'decoration: TextDecoration.underline 下划线',
                style: new TextStyle(
                  decoration: TextDecoration.underline,
                  decorationStyle: TextDecorationStyle.dotted
                )
              ),
            ],
          ),
        ));
  }
}