Global switches are created for rare cases and generally make Leaflet to not detect a particular browser feature even if it’s there. You need to set the switch as a global variable to true before including Leaflet on the page, like this:
全局开关是为罕见情况创建的，通常使Leaflet 无法检测特定的浏览器功能，即使它存在。在页面上包含传单之前，需要将开关作为全局变量设置为true，如下所示：
<script>L_NO_TOUCH = true;</script>
<script src="leaflet.js"></script>
| Switch | Description |
|---|---|
L_NO_TOUCH |
Forces Leaflet to not use touch events even if it detects them.
强制Leaflet 不要使用触摸事件，即使它检测到它们。 |
L_DISABLE_3D |
Forces Leaflet to not use hardware-accelerated CSS 3D transforms for positioning (which may cause glitches in some rare environments) even if they’re supported.
强制Leaflet不要使用硬件加速的CSS 3D转换进行定位（这可能会在一些罕见的环境中导致故障），即使它们受到支持。 |