The TextFormField has a validator method which is called to validate the input. The validator method returns a string containing the error message when the user input is invalid or null if the user input is valid.In most cases, you will use a regular expression to check the input. We ...
注意:无特殊说明,Flutter版本及Dart版本如下: Flutter版本:1.12.13+hotfix.5 Dart版本:2.7.0 Form、FormField、TextFormField是表单相关控件...,类似于H5中form。...validator验证函数,输入的值不匹配的时候返回的字符串显示在TextField的errorText属性位置,返回null,表示没...
...validator; FormField({required this.label, this.validator});}使用封装的表单组件现在我们可以轻松地在任何地方使用CustomForm组件,...在Flutter中,我们可以通过validator回调来实现即时验证,并给用户即时反馈。例如,当用户输入不符合要求时,我们可以立即显示错误信息。...在Flutter中,表单封装涉及到Form和Tex...
this.validator, // 初始值 this.initialValue, // 是否自动校验。 this.autovalidate=false, this.enabled=true, }) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 3. TextFormField 为了方便使用,Flutter 提供了一个 TextFormField ,它继承自 FormField 类,也是 TextField 的一个包装类,所以...
_FormScope是InheritedWidget的子类,用来做数据共享的,从上往下的共享数据,Form的child最终被包装到了_FormScope中。三个函数分别实现了数据校验FormFieldValidator,数据更新FormFieldSetter,构建child widget的FormFieldBuilder,我们拓展的构建的child就是通过FormFieldBuilder函数。我们再仔细看下FormField类,源码如下...
On every form field a validator is present Stepper and form in flutter There are 3 main functions in steppers : onStepContinue onStepCancel onStepTapped If the validation is correct (checked on each and every step), then we go to next step…. ...
flutter 30 new TextFormField( decoration: new InputDecoration(hintText: 'DOB'), maxLength: 10, validator: validateDob, onSaved: (String val) { strDob = val; }, ), Future _selectDate() async { DateTime picked = await showDatePicker( context: context, initialDate: new DateTime.now(), ...
focusNode; const TextInputInputsAtom( {super.key, required this.controller, required this.labelText, this.readOnly = false, this.onTap, this.validator, this.inputDecoration, this.autofillHints, this.inputFormatters, this.keyboardType, this.noLabelTranslation = false, this.noErrorColor = false, ...
final _formKey = GlobalKey<FormBuilderState>(); FormBuilder( key: _formKey, child: Column( children: [ FormBuilderTextField( key: _emailFieldKey, name: 'email', decoration: const InputDecoration(labelText: 'Email'), validator: FormBuilderValidators.compose([ FormBuilderValidators.required(), ...
解决方案:使用 validator 属性提供明确的验证逻辑和错误消息。 给出Flutter 官方文档或其他学习资源的链接以供进一步学习 Flutter 官方文档关于 DropdownButtonFormField 的部分:DropdownButtonFormField Class Flutter 官方文档关于表单的部分:Forms in Flutter 希望这些信息能帮助你更好地理解和使用 Flutter 的 Dropdown...