Flutter/Dart没有数组。请改用列表。

溶液

在api-response中，它总是被格式化为List of Map或Map of List。
Map列表如下：

[

 {
   "name":"ruby",
   "gender":"female"
 },

 {
   "name":"otis",
   "gender":"male"
 },

]

而且，列表的Map类似于：

{
    "data": [
        "Professor",
        "Berlin",
        "Tokyo"
    ]
}

因此，要访问它们，您必须使用JsonDecode，然后查看响应并进行处理。
对于Map响应....

var resMap = jsonDecode(response.body);

对于列表响应（在resMap之后使用密钥，密钥带有密钥）...

var resMap = jsonDecode(response.body);
var infoList = resMap["data"];

演示

class CatTypeController {
  Future<void> getLeaves() async {
    String url = "https://meowfacts.herokuapp.com/?count=2";

    http.Response response = await http.get(Uri.parse(url));

    if (response.statusCode == 200) {
      Map rM = jsonDecode(response.body);
      print(rM["data"]);
    }
  }
}

响应

输出

["In ancient Egypt, killing a cat was a crime punishable by death.","The way you treat kittens in the early stages of it's life will render it's personality traits later in life."]