The specific error reports are as follows:

flutter/lib/ui/ui_ dart_ state.cc(209)] Unhandled Exception: type ‘int’ is not a subtype of type ‘Iterable< dynamic>’

The reason is that I use the get request and the parameters are not spliced after the URL, that is, in this form, XXX?X = 1 & amp; y=2。

But use   Map< String, dynamic>? Query a map to place parameters.

Check the source code to find the reason. If the value in query is not of string type, it will be converted to an iterator, and I put it as an int, so the conversion reports an error. The solution is to convert all the values in the query map into strings.

query?.map((key, value) => MapEntry(key, value.toString()))