Flutter: How to hide suffix icon when there is no input on textformfield?-CodePudding

I have a TextFormField and i want its suffix icon auto hidden when the textfield is empty. Here is my code

child: TextFormField(
                    decoration: InputDecoration(
                      contentPadding:
                      const EdgeInsets.only(top: 16, bottom: 15),
                      border: InputBorder.none,
                      fillColor: Colors.white,
                      prefixIcon: const Padding(
                        padding: EdgeInsets.only(top: 16.0, bottom: 15),
                        child: Text("Code: "),
                      ),
                      prefixIconConstraints: const BoxConstraints(minWidth: 60, minHeight: 19),
                      hintText: "Input code here ",                         
                      suffixIcon: IconButton(
                        onPressed: () {
                        },
                        icon: Icon(Icons.delete),
                      ),
                    ),
                    keyboardType: TextInputType.number,
                  ),

This is how it should look like

Can anyone help me pls.

CodePudding user response：

You can use TextEditingController with a listner

  late final TextEditingController controller = TextEditingController()
    ..addListener(() {
      setState(() {});
    });

TextFormField(
  controller: controller,
  decoration: InputDecoration(
    suffixIcon: controller.text.isEmpty
        ? null
        : IconButton(
            onPressed: () {},
            icon: Icon(Icons.delete),
          ),

CodePudding user response：

      late final TextEditingController controller = TextEditingController()
        ..addListener(() {
              if(controller.text.isEmpty){
          setState(() {});
           }
        });   



              child: TextFormField(
                        decoration: InputDecoration(
                          contentPadding:
                          const EdgeInsets.only(top: 16, bottom: 15),
                          border: InputBorder.none,
                          fillColor: Colors.white,
                          prefixIcon: const Padding(
                            padding: EdgeInsets.only(top: 16.0, bottom: 15),
                            child: Text("Code: "),
                          ),
                          prefixIconConstraints: const BoxConstraints(minWidth: 60, minHeight: 19),
                          hintText: "Input code here ",                         
                         suffixIcon: controller.text.isEmpty
                                     ? null
                                       : IconButton(
                                              onPressed: () {},
                                           icon: Icon(Icons.delete),
                                               ),
                                  ),
                        keyboardType: TextInputType.number,
                      ),

CodePudding user response：

You can also do it using onChanged and setState .

bool show= false;


child:TextFormField(
              onChanged: (value){
                if(value.isNotEmpty){
                  setState(() {
                    show=true;
                  });
                }
                else{
                  setState(() {
                    show=false;
                  });
                }
              } ,
                    decoration: InputDecoration(
                      contentPadding:
                      const EdgeInsets.only(top: 16, bottom: 15),
                      border: InputBorder.none,
                      fillColor: Colors.white,
                      prefixIcon: const Padding(
                        padding: EdgeInsets.only(top: 16.0, bottom: 15),
                        child: Text("Code: "),
                      ),
                      prefixIconConstraints: const BoxConstraints(minWidth: 60, minHeight: 19),
                      hintText: "Input code here ",                         
                      suffixIcon:show? IconButton(
                        onPressed: () {
                        },
                        icon: Icon(Icons.delete),
                      ):null,
                    ),
                    keyboardType: TextInputType.number,
                  ),