从DropdownButton到api的颤振传递数据

Question

我只想映射到api，并在选中项时创建以下DropdownButton，即将数据发布到API

DropdownButton(
                value: 'Item 1',
                icon: const Icon(Icons.keyboard_arrow_down),
                items: [
                  'Item 1',
                  'Item 2',
                  'Item 3',
                  'Item 4',
                  'Item 5',
                ].map((String items) {
                  return DropdownMenuItem(
                    value: items,
                    child: Text(items),
                  );
                }).toList(),
                onChanged: print),

如何映射到api端点并将所选项发布到api？

Answer 1

作为带有整数而不是字符串的post请求：

Future<void> onChangedCallback(int? item) async {
   if(item != null){
     currentValue = item;
     final url = "your_url_here";
     final body = {
          "key_you_want_to_map": item
        };  
     final response = await http.post(Uri.parse(url), body: body);
     print(response.body);
   }
}

...

var currentValue = 1;

DropdownButton(
                value: currentValue,
                icon: const Icon(Icons.keyboard_arrow_down),
                items: <int>[
                  1,
                  2,
                  3,
                  4,
                  5,
                ].map((int i) {
                  return DropdownMenuItem(
                    value: i,
                    child: Text('Item $i'),
                  );
                }).toList(),
                onChanged: onChangedCallback,
                ), // Equivalent of onChanged: (v) async => onChangedCallback(v),