我在我的 flutter 应用程序中为我的表单动态生成文本字段。请检查下面的代码
Widget _buildInputFields(
String label,
TextEditingController textController,
TextInputType textInputType,
IconData icon,
Color iconColor,
) {
return Container(
margin: EdgeInsets.only(left: 20, bottom: 20),
child: Container(
padding: EdgeInsets.only(right: 20),
child: Row(
children: <Widget>[
Flexible(
child: TextFormField(
controller: textController,
validator: (value) {
if (value.isEmpty) {
return 'Please enter some text';
}
},
style: new TextStyle(color: Colors.white),
keyboardType: textInputType,
decoration: InputDecoration(
labelText: label,
fillColor: Colors.white,
labelStyle: TextStyle(
color: Colors.white, fontWeight: FontWeight.w600),
enabledBorder: OutlineInputBorder(
borderSide:
const BorderSide(color: Colors.white30, width: 2.0),
borderRadius: BorderRadius.circular(25.0),
),
suffixIcon: IconButton(
icon: Icon(icon, color: iconColor),
onPressed: () {},
)),
),
),
],
),
));
}
上述方法返回一个具有我需要的样式的 TextFormField
,因此我不必重新编码数百次。我只是调用该方法,我得到一个新的 TextFormField
无论如何,我需要进行表单验证,每个字段都有不同的验证。在 flutter 中,如何将 validator
传递给 textformfield
?
最佳答案
您可以简单地将验证器作为参数传递,就像您对其他验证器所做的那样。您只需要传入一个以字符串作为参数并返回字符串的函数。
//username validator possible structure
Function(String) usernameValidator = (String username){
if(username.isEmpty){
return 'Username empty';
}else if(username.length < 3){
return 'Username short';
}
return null;
};
//password validator possible structure
passwordValidator(String password){
if(password.isEmpty){
return 'Password empty';
}else if(password.length < 3){
return 'PasswordShort';
}
return null;
}
//new build function
Widget _buildInputFields(
String label,
TextEditingController textController,
TextInputType textInputType,
IconData icon,
Color iconColor,
String Function(String) validator
) {
return Container(
margin: EdgeInsets.only(left: 20, bottom: 20),
child: Container(
padding: EdgeInsets.only(right: 20),
child: Row(
children: <Widget>[
Flexible(
child: TextFormField(
controller: textController,
validator: validator,
style: new TextStyle(color: Colors.white),
keyboardType: textInputType,
decoration: InputDecoration(
labelText: label,
fillColor: Colors.white,
labelStyle: TextStyle(
color: Colors.white, fontWeight: FontWeight.w600),
enabledBorder: OutlineInputBorder(
borderSide:
const BorderSide(color: Colors.white30, width: 2.0),
borderRadius: BorderRadius.circular(25.0),
),
suffixIcon: IconButton(
icon: Icon(icon, color: iconColor),
onPressed: () {},
)),
),
),
],
),
));
}
//calling your function
_buildInputFields(label, textController, textInputType, icon, iconColor, usernameValidator);
_buildInputFields(label, textController, textInputType, icon, iconColor, passwordValidator);
关于android - 如何将验证器传递给 Flutter 中的 `TextFormField'?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/55548767/