Flutter之LinearProgressIndicator组

/**
 * LinearProgressIndicator本身不能设置高度，可以包一层父容器设置高度来间接设置LinearProgressIndicator的高度，
 * 如Container，SizedBox等
 *
 * const LinearProgressIndicator({
    Key key,
    double value,//0~1的浮点数，用来表示进度多少;如果 value 为 null 或空，则显示一个动画，否则显示一个定值
    Color backgroundColor,//背景颜色
    Animation<Color> valueColor,//animation类型的参数，用来设定进度值的颜色，默认为主题色
    String semanticsLabel,
    String semanticsValue,
    })
 */

body: ListView(
          children: <Widget>[
            Container(
              padding: EdgeInsets.only(left: 50.0, right: 50.0, top: 50.0),
              child: LinearProgressIndicator(
                value: 0.3,
                backgroundColor: Color(0xff00ff00),
              ),
            ),
            Container(
              padding: EdgeInsets.only(left: 50.0, right: 50.0, top: 50.0),
              child: LinearProgressIndicator(
//                    value: 0.3,
                backgroundColor: Color(0xffff0000),
              ),
            ),
            Container(
              padding: EdgeInsets.only(left: 50.0, right: 50.0, top: 50.0),
              child: LinearProgressIndicator(
                value: 0.3,
                valueColor: new AlwaysStoppedAnimation<Color>(Colors.red),
                backgroundColor: Color(0xff00ff00),
              ),
            ),
            Container(
              padding: EdgeInsets.only(left: 50.0, right: 50.0, top: 50.0),
              child: Container(
                height: 10.0,
                child: LinearProgressIndicator(
                  value: 0.3,
                  valueColor: new AlwaysStoppedAnimation<Color>(Colors.red),
                  backgroundColor: Color(0xff00ff00),
                ),
              ),
            ),
          ],
        ),