很多时候我们 可以在线加载地图，而我们页需要加载不同底图，所以这里我们利用四屏联动，本文主要的是真彩色，加彩色，水体和土壤以及植被指数，最终加载的结果如下：
这个APP的主要函数：
forEach(outputNames)
Creates a Reducer by combining a copy of the given reducer for each output name in the given list. If the reducer has a single output, the output names are used as-is; otherwise they are prefixed to the original output names.
Arguments:
this:reducer (Reducer)
outputNames (List)
Returns: Reducer
ui.Map.Linker(maps, event)
A utility for creating linked maps.
Arguments:
maps (List<Object>, optional):
A list of maps to link.
event (String, optional):
The event