找了很久的代码，可以实现获取验证码的样式，

Container(
            margin: EdgeInsets.only(top: screenAdapter.height(60)),
            padding: EdgeInsets.all(screenAdapter.width(40)),
            child: PinCodeTextField(
              autoFocus: true, //进入就弹出键盘
              keyboardType: TextInputType.number, //调用数字键盘
              length: 6,
              obscureText: false,
              animationType: AnimationType.fade,
              dialogConfig: DialogConfig(
                  //汉化dialog
                  dialogTitle: "黏贴验证码",
                  dialogContent: "确定要黏贴验证码",
                  affirmativeText: "确定",
                  negativeText: "取消"), //配置dialog
              pinTheme: PinTheme(
                //样式
                // 修改边框
                activeColor: Colors.black12, // 输入文字后边框的颜色
                selectedColor: Colors.orange, // 选中边框的颜色
                inactiveColor: Colors.black12, //默认的边框颜色
                //背景颜色
                activeFillColor: Colors.white,
                selectedFillColor: Colors.orange,
                inactiveFillColor: const Color.fromRGBO(245, 245, 245, 1),

                shape: PinCodeFieldShape.box,
                borderRadius: BorderRadius.circular(5),
                fieldHeight: 50,
                fieldWidth: 40,
              ),
              animationDuration: const Duration(milliseconds: 300),
              enableActiveFill: true,
              controller: controller.editingController, //TextFiled控制器
              onCompleted: (v) {
                print("Completed");
              },
              onChanged: (value) {
                print(value);
              },
              beforeTextPaste: (text) {
                print("Allowing to paste $text");
                return true;
              },
              appContext: context, //注意需要传入context
            ),
          ),
          SizedBox(
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                TextButton(onPressed: () {}, child: Text("重新发送验证码")),
                TextButton(onPressed: () {}, child: Text("帮助")),
              ],
            ),
          ),
          PassButton(
              text: "获取验证码",
              onPressed: () {
                print(controller.editingController.text);
                // 隐藏键盘
                FocusScope.of(context).requestFocus(FocusNode());
              }),

可以根据不同的需求进行调整代码风格，还有能获取到验证码的