日志上写着 I/flutter (28204): The method 'add' was called on null.I/flutter (28204): Receiver: null
I/flutter (28204): Tried calling: add("8a041434-0703-11eb-adc1-0242ac120002") 我的代码是: List<String>hospitalIds=List<<
我正在尝试用JSON文件中的一些数据填充Flutter中的列表。但是,我的代码一直抛出异常"NoSuchMethodError (NoSuchMethodError: The method 'add' was called on null." 我的错误在哪里?JSON: { "#2": null, "
我从一个API请求中获取值,并将它们存储到要添加到List<String>的String变量中。当打印这个变量时,prints是很好的,但是当我将它们添加到列表中时,我会得到NoSuchMethodError: The method 'add' was called on null.。方法如下: Future<List<String>> getCityDb(String isoLocationDb) async {
但是我得到了这个错误ava.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.util.ArrayList.add(java.lang.Object)' on a null object reference代码 for (