三 表单组件基本用法
3.1 基本用法代码
Form(child: Column(
children: [
Text(“用户名：”),
TextFormField(),
Text(“密码：”),
TextFormField(),
RaisedButton(onPressed: (){},child: Text(“登录”),)
],
),)
3.2 效果图四 表单属性用法
4.1 表单属性代码
//变量定义
var userNameController = new TextEditingController();
var passWordController = new TextEditingController();
var _userNameFieldValue = ‘’;
var _passWordFieldValue = ‘’;
var _name = ‘’;
var _pwd = ‘’;
final _formKey = GlobalKey();
//body部分
body: Form(
key: _formKey,
onWillPop: () async {
return await showDialog(
context: context,
builder: (BuildContext context) {
return alertDialog(
title: Text(‘提示’),
content: Text(‘确认退出吗？’),
actions: [
FlatButton(
child: Text(‘取消’),
onPressed: () {
Navigator.of(context).pop(false);
},
),
FlatButton(
child: Text(‘确认’),
onPressed: () {
Navigator.of(context).pop(true);
},
),
],
);
});
},
//autovalidateMode:AutovalidateMode.disabled ,
child: Column(
children: [
Text(
“用户名”,
style: TextStyle(
color: Colors.black,
fontSize: 16,
fontWeight: FontWeight.bold),
),
TextFormField(
controller: userNameController,
decoration: InputDecoration(
icon: Icon(Icons.person),
suffixIcon: Icon(Icons.delete),
labelText: “请输入用户名”,
counterText: “${_userNameFieldValue.length}/32”),
autovalidateMode: AutovalidateMode.disabled,
validator: (userName) {
if (userName.length < 3) {
return “用户名过短”;
}
return null;
},
onChanged: (value) {
setState(() {
_userNameFieldValue = value;
});
},
onSaved: (value) {
_name = value;
},
keyboardType: TextInputType.number,
textCapitalization: TextCapitalization.words,
textInputAction: TextInputAction.search,
),
Text(“密码”,
style: TextStyle(
color: Colors.black,
fontSize: 16,
fontWeight: FontWeight.bold)),
TextFormField(
controller: passWordController,
decoration: InputDecoration(
icon: Icon(Icons.lock),
suffixIcon: Icon(Icons.delete),
labelText: “请输入密码”,
counterText: "${_passWordF
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ieldValue.length}/32",
),
autovalidateMode: AutovalidateMode.disabled,
obscureText: true,
validator: (passWord) {
if (passWord.length < 3) {
return “密码过短”;
}
return null;
},
onChanged: (value) {
setState(() {
_passWordFieldValue = value;
});
},
onSaved: (value) {
_pwd = value;
},
),
RaisedButton(
onPressed: () {
var _state = _formKey.currentState;
if (_state.validate()) {
_state.save();
login(_name, _pwd);
}
//login(_userNameFieldValue, _passWordFieldValue);
},
child: Text(“登录”),
)
],
),
onChanged: () {
//print(“用户名：${userNameController.text}”);
//print(“密码：${passWordController.text}”);
},
));
//login方法
void login(String name, String pwd)
{
print(“用户名： n a m e , 密 码 ： name,密码： name,密码：_pwd”);
userNameController.clear();
passWordController.clear();
}
4.2 效果图 4.3 Form属性| 属性 | 说明 | 取值 |
| :-: | :-: | :-: |
| key | 整个应用程序中唯一的密钥 | Key对象 |
| onWillPop | 返回按钮拦截后的小控件的方法 | WillPopCallback对象 |
| autovalidateMode | 输入框变化校验 | bool对象 |
| onChanged | 输入框发生变化时的回调函数 | Function对象 |
lear();
}
4.2 效果图[外链图片转存中…(img-jlE3KApA-1640844230652)]
4.3 Form属性| 属性 | 说明 | 取值 |
| :-: | :-: | :-: |
| key | 整个应用程序中唯一的密钥 | Key对象 |
| onWillPop | 返回按钮拦截后的小控件的方法 | WillPopCallback对象 |
| autovalidateMode | 输入框变化校验 | bool对象 |
| onChanged | 输入框发生变化时的回调函数 | Function对象 |
