如果 body:Form 没有在颤振应用程序中使用，我的表单数据没有被提交或保存
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【中文标题】如果 body:Form 没有在颤振应用程序中使用，我的表单数据没有被提交或保存【英文标题】：My Form data is not getting submitted or saved if body:Form is not used in flutter appplication 【发布时间】：2021-04-02 17:20:20 【问题描述】：如果 body:Form 未在 Flutter 应用程序中使用，我的表单数据不会被提交或保存。
如果使用 body:Form 而不是 SingleChildScrollView 我的整个表单页面或包含 12 到 13 个文本项的小部件不可见，包括“上传”或“提交”按钮。
这是我的代码
body: Form(
key: formKey,
child: Center(
child: Column(
children: <Widget>[
SizedBox(height: 20,), //just for spacing
Column(
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
Padding(padding: EdgeInsets.only(top: 15)),
Container(
child: imageFile==null?
FlatButton(
onPressed: ()
_showDialog();
,
child: Icon(Icons.add_a_photo,size: 80,color: Color(0xffff2fc3),)
):
Image.file(imageFile,width: 200,height: 100,),
),
SizedBox(height: 10,),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Expanded(
flex: 1,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Theme(
data: ThemeData(
hintColor: Colors.blue,
),
child: TextFormField(
validator: (value)
if(value.isEmpty)
return "Please write a";
else
a = value;
,
keyboardType: TextInputType.name,
autofocus: false,
decoration: InputDecoration(
labelText: 'A',
),
maxLength: 15,
),
),
),
),
Expanded(
flex: 1,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Theme(
data: ThemeData(
hintColor: Colors.blue,
),
child: TextFormField(
validator: (value)
if(value.isEmpty)
return "Please write the b";
else
b= value;
,
keyboardType: TextInputType.name,
autofocus: false,
decoration: InputDecoration(
labelText: 'B',
),
maxLength: 15,
),
),
),
),
],
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Expanded(
flex: 1,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Theme(
data: ThemeData(
hintColor: Colors.blue,
),
child: TextFormField(
validator: (value)
if(value.isEmpty)
return "Please write the C";
else
c = value;
,
keyboardType: TextInputType.name,
autofocus: false,
decoration: InputDecoration(
labelText: 'C',
),
maxLength: 15,
),
),
),
),
Expanded(
flex: 1,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Theme(
data: ThemeData(
hintColor: Colors.blue,
),
child: TextFormField(
validator: (value)
if(value.isEmpty)
return "Please write the D";
else
d = value;
,
keyboardType: TextInputType.name,
autofocus: false,
decoration: InputDecoration(
labelText: 'D',
),
maxLength: 15,
),
),
),
),
],
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Expanded(
flex: 1,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Theme(
data: ThemeData(
hintColor: Colors.blue,
),
child: TextFormField(
validator: (value)
if(value.isEmpty)
return "Please write the E";
else
e = value;
,
keyboardType: TextInputType.name,
autofocus: false,
decoration: InputDecoration(
labelText: 'E ',
),
maxLength: 15,
),
),
),
),
Expanded(
flex: 1,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Theme(
data: ThemeData(
hintColor: Colors.blue,
),
child: TextFormField(
validator: (value)
if(value.isEmpty)
return "Please write the F";
else
f = value;
,
keyboardType: TextInputType.number,
autofocus: false,
decoration: InputDecoration(
labelText: 'F',
),
maxLength: 15,
),
),
),
),
],
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Expanded(
flex: 1,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Theme(
data: ThemeData(
hintColor: Colors.blue,
),
child: TextFormField(
validator: (value)
if(value.isEmpty)
return "Please write the G";
else
g = value;
,
keyboardType: TextInputType.name,
autofocus: false,
decoration: InputDecoration(
labelText: ' G ',
),
maxLength: 15,
),
),
),
),
Expanded(
flex: 1,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Theme(
data: ThemeData(
hintColor: Colors.blue,
),
child: TextFormField(
validator: (value)
if(value.isEmpty)
return "Please write H";
else
h = value;
,
keyboardType: TextInputType.name,
autofocus: false,
decoration: InputDecoration(
labelText: ' H ',
),
maxLength: 15,
),
),
),
),
],
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Expanded(
flex: 1,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Theme(
data: ThemeData(
hintColor: Colors.blue,
),
child: TextFormField(
validator: (value)
if(value.isEmpty)
return "Please write the I";
else
i = value;
,
keyboardType: TextInputType.number,
autofocus: false,
decoration: InputDecoration(
labelText: 'I',
),
maxLength: 15,
),
),
),
),
Expanded(
flex: 1,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Theme(
data: ThemeData(
hintColor: Colors.blue,
),
child: TextFormField(
validator: (value)
if(value.isEmpty)
return "Please write J";
else
j = value;
,
keyboardType: TextInputType.name,
autofocus: false,
decoration: InputDecoration(
labelText: ' J ',
),
maxLength: 15,
),
),
),
),
],
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Expanded(
flex: 1,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Theme(
data: ThemeData(
hintColor: Colors.blue,
),
child: TextFormField(
validator: (value)
if(value.isEmpty)
return "Please write the K";
else
k = value;
,
keyboardType: TextInputType.name,
autofocus: false,
decoration: InputDecoration(
labelText: ' K ',
),
maxLength: 15,
),
),
),
),
SizedBox(width: 5,),
],
),
RaisedButton(
onPressed: ()
if(imageFile == null)
Fluttertoast.showToast(
msg: "Please select an image",
gravity: ToastGravity.CENTER,
toastLength: Toast.LENGTH_LONG,
timeInSecForiosWeb: 2
);
else
upload();
,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(10),
),
color: Color(0xffff2fc3),
child: Text("Upload",style: TextStyle(fontSize: 18,color: Colors.blue),),
)
],//Widget
),//Column
],Widget
),//column
),//Center
),//Form
);Scaffold
如果我使用了 body:SingleChildScrollView 我的表单小部件正在滚动，并且上传或提交按钮可见，但无法将表单数据保存或存储到 firebase 数据库中。
如果 body:Form ( ) 仅包含 5 个或更少的项目，则一切正常，因为我看到“上传”或“提交”按钮并能够提交表单数据。
请解决我的问题。
错误：当使用滚动视图并单击提交或上传按钮时
E/flutter (29120)：[错误：flutter/lib/ui/ui_dart_state.cc(166)] 未处理的异常：NoSuchMethodError：方法“验证”在 null 上调用。 E/颤振（29120）：接收器：空 E/flutter (29120): 尝试调用: validate() E/flutter (29120): #0 _UploadDataState.upload (package:scarves_store/UploadData.dart:587) E/颤振（29120）：#1 _UploadDataState.build。 （包：scarves_store/UploadData.dart:519） E/flutter (29120): #2 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:992) E/颤振（29120）：#3 _InkResponseState.build。 （包：flutter/src/material/ink_well.dart:1098） E/flutter (29120): #4 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:184) E/flutter (29120): #5 TapGestureRecognizer.handleTapUp (package:flutter/src/gestures/tap.dart:524) E/flutter (29120): #6 BaseTapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:301) E/flutter (29120): #7 BaseTapGestureRecognizer.acceptGesture (package:flutter/src/gestures/tap.dart:256) E/flutter (29120): #8 GestureArenaManager.sweep (package:flutter/src/gestures/arena.dart:158) E/flutter (29120): #9 GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:224) E/flutter (29120): #10 GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:200) E/flutter (29120): #11 GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:158) E/flutter (29120): #12 GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:104) E/flutter (29120): #13 GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:88) E/flutter (29120): #14 _rootRunUnary (dart:async/zone.dart:1206) E/flutter (29120): #15 _CustomZone.runUnary (dart:async/zone.dart:1100) E/flutter (29120): #16 _CustomZone.runUnaryGuarded (dart:async/zone.dart:1005) E/flutter (29120): #17 _invoke1 (dart:ui/hooks.dart:267) E/flutter (29120): #18 _dispatchPointerDataPacket (dart:ui/hooks.dart:176) E/颤动（29120）：
【问题讨论】：
请添加upload();方法 Future请试试这个：
body: SingleChildScrollView(
child: Center(
child: Form(
key: formKey,
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
SizedBox(height: 20,), //just for spacing
.....// OTHER WIDGETS
],
),
),
),
),
【讨论】：
Ok Mohammed 我会在尝试您的代码后更新您，谢谢。 谢谢你 Mohammed ，你已经完全解决了我的问题。再次感谢。和我在一起请同时关注我在堆栈上的其他查询。如果我想就我的 Flutter 查询与您沟通，我应该如何联系您？ 你可以回复我的stack账号 好的，请在这里回答***.com/questions/65435218/… Mohammad_Asef 请尝试在这里回答我的问题***.com/questions/65395772/…以上是关于如果 body:Form 没有在颤振应用程序中使用，我的表单数据没有被提交或保存的主要内容，如果未能解决你的问题，请参考以下文章