我正在使用 firebase 发布底部表格的代码，并且还有下拉菜单，因此您可以从此代码中获取帮助。
Widget updatebottomSheet()
{
Size size = MediaQuery.of(context).size;
String _dropDownValue;
String starthoour;
String endhour;
String startminute;
String endminute;
showModalBottomSheet(
enableDrag: false,
isDismissible: false,
isScrollControlled: true,
context: context,
builder:(context)
{
return GestureDetector(
behavior: HitTestBehavior.opaque,
child: SingleChildScrollView(
child: Container(
padding: EdgeInsets.only(bottom: MediaQuery.of(context).viewInsets.bottom+10),
// height: size.height*0.6,
decoration: BoxDecoration(
color: Colors.white,
),
child: Column(
children: [
Padding(
padding: const EdgeInsets.all(25.0),
child: Container(
decoration: BoxDecoration(
//color: Colors.red,
borderRadius: BorderRadius.circular(20),
),
height: size.height*0.6,
width: double.infinity,
child: Card(
elevation: 4,
child: Padding(
padding: const EdgeInsets.all(12.0),
child: Form(
key: _formKey,
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.start,
children: [
NameField(
controller: teacherid,
icon: Icons.person,
hintText: "Please enter Teacher id",
text: "you not enter name",
onchanged: (value)
{
Administrative.instance.addteacherId=value;
},
),
NameField(
controller:name ,
icon: Icons.meeting_room_outlined,
hintText: "Please enter room no",
text: "you not enter room no",
onchanged: (value)
{
Administrative.instance.room=value;
},
),
FirebaseFirestore.instance.collection("Section").where("collegeId",isEqualTo:cond).snapshots()==null?Container():StreamBuilder(
stream:FirebaseFirestore.instance.collection("Section").where("collegeId",isEqualTo:cond).snapshots(),
builder: (BuildContext context,AsyncSnapshot<QuerySnapshot>snapshot) {
var length = snapshot.data.docs.length;
// DocumentSnapshot ds = snapshot.data.docs[length];
return DropdownButton(
hint: _dropDownValue==null
? Text("Choose Section")
:Text(_dropDownValue,style: TextStyle(color: Colors.blue),),
isExpanded: true,
iconSize: 30,
items:snapshot.data.docs.map((DocumentSnapshot document)
{
return DropdownMenuItem<String>(
value: document.data()["SectionName"],
child: Text(document.data()["SectionName"]),
);
}
).toList(),
onChanged: (value){
setState(() {
_dropDownValue=value;
});
},
);
}
),
SizedBox(height: 10,),
Row(
children: [
Padding(
padding: const EdgeInsets.only(right:8.0),
child: Text("Lecture Start time:",style: TextStyle(color: Colors.black,fontWeight: FontWeight.bold),),
),
Padding(
padding: const EdgeInsets.only(right:20.0),
child: DropdownButton(
hint: starthoour == null
? Text('Choose')
: Text(
starthoour,
style: TextStyle(color: Colors.blue),
),
isExpanded: false,
iconSize: 40.0,
style: TextStyle(color: Colors.blue),
items: ['7 AM', '8 AM', '9 AM',"10 AM","11 AM","12 AM","1 PM","2 PM","3 PM","4 PM","5 PM","6 PM","7 PM","8 PM","9 PM","10 PM"].map(
(val) {
return DropdownMenuItem<String>(
value: val,
child: Text(val),
);
},
).toList(),
onChanged: (val) {
setState(
() {
starthoour = val;
},
);
},
),
),
DropdownButton(
hint: startminute == null
? Text('Choose')
: Text(
startminute,
style: TextStyle(color: Colors.blue),
),
isExpanded: false,
iconSize: 40.0,
style: TextStyle(color: Colors.blue),
items: ['10', '20', '30',"40","50","60"].map(
(val) {
return DropdownMenuItem<String>(
value: val,
child: Text(val),
);
},
).toList(),
onChanged: (val) {
setState(
() {
startminute = val;
},
);
},
),
],
),
SizedBox(height: 20,),
Row(
children: [
Padding(
padding: const EdgeInsets.only(right:8.0),
child: Text("Lecture End time:",style: TextStyle(color: Colors.black,fontWeight: FontWeight.bold),),
),
Padding(
padding: const EdgeInsets.only(right:20.0),
child: DropdownButton(
hint: endhour == null
? Text('Choose')
: Text(
endhour,
style: TextStyle(color: Colors.blue),
),
isExpanded: false,
iconSize: 40.0,
style: TextStyle(color: Colors.blue),
items: ['7 AM', '8 AM', '9 AM',"10 AM","11 AM","12 AM","1 PM","2 PM","3 PM","4 PM","5 PM","6 PM","7 PM","8 PM","9 PM","10 PM"].map(
(val) {
return DropdownMenuItem<String>(
value: val,
child: Text(val),
);
},
).toList(),
onChanged: (val) {
setState(
() {
endhour = val;
},
);
},
),
),
DropdownButton(
hint: endminute == null
? Text('Choose')
: Text(
endminute,
style: TextStyle(color: Colors.blue),
),
isExpanded: false,
iconSize: 40.0,
style: TextStyle(color: Colors.blue),
items: ['10', '20', '30',"40","50","60"].map(
(val) {
return DropdownMenuItem<String>(
value: val,
child: Text(val),
);
},
).toList(),
onChanged: (val) {
setState(
() {
endminute = val;
},
);
},
),
],
),
],
),
),
),
),
),
),
Padding(
padding: const EdgeInsets.only(left: 20.0,right: 20.0,top: 8.0,bottom: 8.0),
child: Container(
width: double.infinity,
height: 60,
child: FlatButton(
color: Colors.black,
onPressed: () {
if(!_formKey.currentState.validate()){
return;
}
else
{
if(_dropDownValue==null||endminute==null||endhour==null||startminute==null||starthoour==null)
{
Fluttertoast.showToast(
msg: "Please choose properly from DropDown",
toastLength: Toast.LENGTH_LONG,
gravity: ToastGravity.CENTER,
timeInSecForIosWeb: 1,
backgroundColor: Colors.redAccent,
textColor: Colors.white,
fontSize: 16.0
);
}
else
{
_formKey.currentState.validate();
addslot(_dropDownValue,starthoour,startminute,endhour,endminute);
}
}
},
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(10.0),
),
child: Text("Save",style: TextStyle(color: Colors.white,fontSize: 18,fontWeight: FontWeight.bold),),
),
),
),
Padding(
padding: const EdgeInsets.only(left: 20.0,right: 20.0,top: 8.0,bottom: 8.0),
child: Container(
width: double.infinity,
height: 60,
child: FlatButton(
color: Colors.black,
onPressed: (){
Navigator.pop(context);
},
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(10.0),
),
child: Text("Cancel",style: TextStyle(color: Colors.white,fontSize: 18,fontWeight: FontWeight.bold),),
),
),
),
],
),
),
),
);
}
);
}