图标不可见

Question

我似乎无法理解为什么我的应用程序没有在应用程序中显示图标，尽管它在 android studio IDE 中显示。也不会产生任何错误

未在应用中显示

代码如下：

   

 CustomFromField(
                              heading: getTranslated(context, "sample_id"),
                              suffixIcon:IconButton(onPressed: ()=> showDialog(context: context, builder: (context)=> alert) ,icon:Icon(Icons.info)),
                              controller: idno,
                              keybardType: TextInputType.number,
                              ),
                              
                          
  

    class CustomFromField extends StatefulWidget {
      final String heading;
      final String hintText;
      final TextEditingController controller;
      final bool hideText;
      final TextInputType keybardType;
      final TextInputAction textInputAction;
      final Color headingColor;
      // final FocusNode focusNode;
      final Widget suffixIcon;
      Function onChanged;
      Function validation;
      Function onTap;
      CustomFromField(
          {this.hintText = '',
            this.controller,
            this.hideText = false,
            this.keybardType,
            this.onChanged,
            this.suffixIcon,
            this.validation,
            this.headingColor,
            this.onTap,
            this.heading,
            // this.focusNode,
            this.textInputAction = TextInputAction.next});
      @override
      _CustomFromFieldState createState() => _CustomFromFieldState();
    }
    
    class _CustomFromFieldState extends State<CustomFromField> {
      @override
      Widget build(BuildContext context) {
        return Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Padding(
              padding: const EdgeInsets.only(bottom: 8.0, left: 8),
              child: Text(
                widget.heading,
                style: TextStyle(
                    color: AppColor.primarypurple,
                    fontSize: 14,
                    fontWeight: FontWeight.w500),
              ),
            ),
            Container(
              child: TextFormField(
                onChanged: widget.onChanged,
                controller: widget.controller,
                obscureText: widget.hideText,
                textInputAction: widget.textInputAction,
                keyboardType: widget.keybardType,
                validator: widget.validation,
                onTap: widget.onTap,
                // focusNode: widget.focusNode,
                style: TextStyle(color: AppColor.primaryColor, fontSize: 14),
                decoration: InputDecoration(
                    isDense: true,
                    contentPadding:
                    EdgeInsets.symmetric(horizontal: 10, vertical: 10),
                    border: new OutlineInputBorder(
                        borderRadius: const BorderRadius.all(
                          const Radius.circular(10.0),
                        ),
                        borderSide:
                        BorderSide(color: AppColor.primaryColor, width: 2)),
                    focusedBorder: new OutlineInputBorder(
                        borderRadius: const BorderRadius.all(
                          const Radius.circular(10.0),
                        ),
                        borderSide:
                        BorderSide(color: AppColor.primaryColor, width: 2)),
                    enabledBorder: new OutlineInputBorder(
                        borderRadius: const BorderRadius.all(
                          const Radius.circular(10.0),
                        ),
                        borderSide: BorderSide(color: AppColor.darkBlue, width: 2)),
                    filled: true,
                    hintText: widget.hintText,
                    hintStyle: TextStyle(color: AppColor.secondaryColor, fontSize: 14),
                    focusColor: AppColor.primaryColor,
                    labelStyle: TextStyle(color: AppColor.primaryColor),
                    fillColor: AppColor.backGrey),
              ),
            ),
            const SizedBox(
              height: 15,
            )
          ],
        );
      }
    }

我正在研究，一种解决方案是检查 uses-material design:true 是否添加到 pubspec.yaml 中，但这对我的项目没有影响。