如何更改下拉下划线的颜色

Question

在我的代码中

Container(height: 1, color: UtilColors.grey),

没有给出预期的输出

Container(
              margin: EdgeInsets.only(left: 52, right: 48),
              child: DropdownButton<String>(
                isExpanded: true,
                //Container(height: 1, color: UtilColors.grey),
                value: _selectedUser,
                items: _userTypes.map((String value) {
                  return new DropdownMenuItem<String>(value: value, child: new Text(value));
                }).toList(),
               /* decoration: InputDecoration(contentPadding: EdgeInsets.only(left: 15), suffixIcon: IconButton(onPressed: () {
                 // _userTypes.map((String value){return new DropdownMenuItem<String>(value: value, child: new Text(value));}).toList();
                   }, icon: Icon(null),)),*/
                icon: Icon(Icons.keyboard_arrow_down),
                hint: Text(UtilString.userType),
                onChanged: (value) => setState(() => _selectedUser = value),
              ),
            ),

Answer 1

终于用 DropdownButton 找到了解决方案 -

下划线：容器（高度：2， 颜色：Colors.deepPurpleAccent,),

这将更改下拉菜单下划线颜色。

Answer 2

 DropdownButtonFormField(


                                              decoration: InputDecoration(
                                             focusedBorder: new UnderlineInputBorder(
                                              borderSide: BorderSide(
                                              color: Colors.black
                                              ),),


                                                enabledBorder: OutlineInputBorder(
                                                  borderSide: BorderSide(color:  Color(0xff22a39f), width: 2),

                                                ),
                                             ),
                                            // iconEnabledColor:  Color(0xff22a39f),


                                            hint: Text("اختر صنف"),

                                            value:selectedValueInDropDpownM ,
                                            items: choosenResala?.ctegoriesDetails.map(( value) {
                                              return DropdownMenuItem<String>(


                                                value: value.catName,
                                                child: Text(value.catName,style: TextStyle( fontSize:
                                                screenWidth * 0.013,
                                                    fontWeight:
                                                    FontWeight.w400,color: Colors.black ),),
                                              );
                                            }).toList(),
                                            onChanged: ( newVal) {
                                              setState(() {
                                                selectedValueInDropDpownM=newVal as String?;
                                              });


                                            },
                                          )