Flutter中如何为NavigationRail指示器添加内边距或增大尺寸？

我有一段简单的NavigationRail代码如下：

NavigationRail(
            destinations: [
              NavigationRailDestination(
                icon: FaIcon(FontAwesomeIcons.list),
                label: Text("Parkings"),
              ),
              const NavigationRailDestination(
                icon: FaIcon(FontAwesomeIcons.mapLocationDot),
                label: Text("Map View"),
              ),
              const NavigationRailDestination(
                icon: FaIcon(FontAwesomeIcons.chartLine),
                label: Text("Metrics"),
              ),
            ],
            indicatorShape: CircleBorder(
              side: BorderSide(width: 1.0),
            ),
            selectedIndex: 0,
          ),

运行后发现指示器与图标距离过近，请问如何为该指示器添加内边距或增大其尺寸，以拉开两者间距？

方法1：全局设置指示器内边距 #

直接给NavigationRail添加indicatorPadding参数，通过内边距拉开指示器与内部图标的距离，这是最快捷的全局调整方式：

NavigationRail(
            destinations: [
              // 保留原导航项配置
              NavigationRailDestination(
                icon: FaIcon(FontAwesomeIcons.list),
                label: Text("Parkings"),
              ),
              const NavigationRailDestination(
                icon: FaIcon(FontAwesomeIcons.mapLocationDot),
                label: Text("Map View"),
              ),
              const NavigationRailDestination(
                icon: FaIcon(FontAwesomeIcons.chartLine),
                label: Text("Metrics"),
              ),
            ],
            indicatorShape: CircleBorder(
              side: BorderSide(width: 1.0),
            ),
            // 调整内边距数值以达到合适间距
            indicatorPadding: EdgeInsets.all(8.0),
            selectedIndex: 0,
          ),

方法2：自定义指示器（灵活控制尺寸与样式） #

如果需要同时调整指示器的大小和内边距，可通过indicator参数自定义容器，完全替代默认指示器样式：

NavigationRail(
            destinations: [
              // 保留原导航项配置
              NavigationRailDestination(
                icon: FaIcon(FontAwesomeIcons.list),
                label: Text("Parkings"),
              ),
              const NavigationRailDestination(
                icon: FaIcon(FontAwesomeIcons.mapLocationDot),
                label: Text("Map View"),
              ),
              const NavigationRailDestination(
                icon: FaIcon(FontAwesomeIcons.chartLine),
                label: Text("Metrics"),
              ),
            ],
            // 自定义圆形指示器，可自由调整宽高、内边距和边框样式
            indicator: Container(
              width: 40,
              height: 40,
              padding: EdgeInsets.all(6.0),
              decoration: BoxDecoration(
                shape: BoxShape.circle,
                border: BorderSide(width: 1.0),
              ),
            ),
            selectedIndex: 0,
          ),

方法3：单独调整图标间距 #

如果只需调整某几个图标的间距，可在图标外层包裹Padding组件：

NavigationRailDestination(
  icon: Padding(
    padding: EdgeInsets.all(6.0),
    child: FaIcon(FontAwesomeIcons.list),
  ),
  label: Text("Parkings"),
),

内容的提问来源于stack exchange，提问作者Munsif Ali