Listview 如何从函数内部检索Firestore数据?
我试图从一个按钮调用函数中的firestore数据,集合的标题。当我刚在一个onPressed中使用它时,它就起作用了:Listview 如何从函数内部检索Firestore数据?,listview,flutter,dart,google-cloud-firestore,string-interpolation,Listview,Flutter,Dart,Google Cloud Firestore,String Interpolation,我试图从一个按钮调用函数中的firestore数据,集合的标题。当我刚在一个onPressed中使用它时,它就起作用了: Expanded( child: IconButton( icon: Icon( Icons.share, onPressed: () => Share.share( '${(snapshot.data.documents[index]['title'])}', //this displays th
Expanded(
child: IconButton(
icon: Icon(
Icons.share,
onPressed: () => Share.share(
'${(snapshot.data.documents[index]['title'])}', //this displays the 'title'
fields of my firestore collections in ListView
))),
但是,当尝试从函数(在不同的共享插件中)调用时,无论我尝试什么,都只打印实际代码而不是内容,如何在下面的函数中检索firestore集合的“标题”,我认为字符串插值${像这样}是唯一的方法,但它不适用于此:
MaterialButton(
child: Text('Share text'),
onPressed: () async => await _shareText(),
),
功能:
Future<void> _shareText() async {
try {
Share.text('my text title',
'HERE => This is my text to share with other applications.', 'text/plain');
// no variation of ${snapshot.data.documents[index]['title']} works here
} catch (e) {
print('error: $e');
}}
还有别的办法叫这个吗
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter_staggered_grid_view/flutter_staggered_grid_view.dart';
import 'dart:ui';
import 'package:google_fonts/google_fonts.dart';
import 'package:material_design_icons_flutter/material_design_icons_flutter.dart';
import 'package:esys_flutter_share/esys_flutter_share.dart';
import 'dart:async';
import 'image.dart';
class Recipe extends StatefulWidget {
@override
_RecipeState createState() => _RecipeState();
}
class _RecipeState extends State<Recipe> {
var firestoreDb = Firestore.instance.collection("recipes").snapshots();
// THIS ${(snapshot.data.documents[index].data['title'])} does not work in
share plugin:
Future<void> _shareText() async {
try {
Share.text('Share Text ',
'${(snapshot.data.documents[index].data['title'])}', 'text/plain');
} catch (e) {
print('error: $e');
}
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Container(
padding: const EdgeInsets.all(8.0),
child: Text(
'Recipes',
style: GoogleFonts.lato(
fontSize: 22.0,
color: Colors.amberAccent.shade50,
),
)),
IconButton(
icon: Icon(MdiIcons.foodForkDrink, color: Color(0xffffe0b2),
size: 32.0),
onPressed: () {
null;
},
),
]),
backgroundColor: Colors.lightBlue,
elevation: 50.0,
), //AppBar
body: Container(
width: MediaQuery.of(context).size.width,
child: StreamBuilder(
stream: firestoreDb,
builder: (context, snapshot) {
if (!snapshot.hasData) Text('Loading...');
return StaggeredGridView.countBuilder(
crossAxisCount: 2,
mainAxisSpacing: 1.0,
crossAxisSpacing: 1.0,
padding: EdgeInsets.symmetric(horizontal: 2.0, vertical: 6.0),
shrinkWrap: true,
itemCount: snapshot.data.documents.length,
itemBuilder: (context, int index) => Container(
child: Column(
children: <Widget>[
Card(
color: Colors.white,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(12.0),
),
child: Column(children: <Widget>[
ListTile(
title: Text(
'${(snapshot.data.documents[index]['title'])}',
style: GoogleFonts.lato(
fontSize: 20.0,
height: 1.2,
fontWeight: FontWeight.w500,
),
textAlign: TextAlign.center,
),
subtitle: Row(
mainAxisSize: MainAxisSize.max,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
MaterialButton(
child: Text('Share text'),
onPressed: () async => await _shareText(),
),
SizedBox(height: 5.0),
ImageInput(), //this displays image called
from image_picker to share , it works for sharing an image.
Expanded(
child: Text(
'${(snapshot.data.documents[index]
['subtitle'])}',
textAlign: TextAlign.right,
style: GoogleFonts.lato(
fontSize: 13.0,
fontWeight: FontWeight.w900,
fontStyle: FontStyle.italic,
color: Colors.blue,
),
), //subtitle: Text
),
] //children
), //Row
), //listtile
]),
),
],
),
),
staggeredTileBuilder: (int index) => StaggeredTile.fit(2),
);
}),
),
);
} //build
} //class
import'包装:flift/cupertino.dart';
进口“包装:颤振/材料.省道”;
导入“包:cloud_firestore/cloud_firestore.dart”;
导入“包:颤振交错网格视图/颤振交错网格视图.省道”;
导入“dart:ui”;
导入“package:google_fonts/google_fonts.dart”;
导入“包装:材料\设计\图标\颤振/材料\设计\图标\颤振.dart”;
导入“包:esys_flatter_share/esys_flatter_share.dart”;
导入“dart:async”;
导入“image.dart”;
类Recipe扩展了StatefulWidget{
@凌驾
_RecipeState createState()=>\u RecipeState();
}
类_RecipeState扩展状态{
var firestoreDb=Firestore.instance.collection(“recipes”).snapshots();
//此${(snapshot.data.documents[index].data['title'])}在中不起作用
共享插件:
Future\u shareText()异步{
试一试{
Share.text('Share text',
“${(snapshot.data.documents[index.data['title'])}”,“text/plain”);
}捕获(e){
打印('error:$e');
}
}
@凌驾
小部件构建(构建上下文){
返回脚手架(
appBar:appBar(
标题:世界其他地区(
mainAxisAlignment:mainAxisAlignment.space,
儿童:[
容器(
填充:常数边集全部(8.0),
子:文本(
“食谱”,
风格:GoogleFonts.lato(
字体大小:22.0,
颜色:Colors.amberAccent.shade50,
),
)),
图标按钮(
图标:图标(MDICONS.FoodWorkDrink,颜色:颜色(0xffffe0b2),
尺寸:32.0),
已按下:(){
无效的
},
),
]),
背景颜色:颜色。浅蓝色,
标高:50.0,
),//AppBar
主体:容器(
宽度:MediaQuery.of(context).size.width,
孩子:StreamBuilder(
流:firestoreDb,
生成器:(上下文,快照){
如果(!snapshot.hasData)文本('Loading…');
返回EdgridView.countBuilder(
交叉轴计数:2,
主轴间距:1.0,
交叉轴间距:1.0,
填充:边缘组。对称(水平:2.0,垂直:6.0),
收缩膜:对,
itemCount:snapshot.data.documents.length,
itemBuilder:(上下文,int索引)=>容器(
子:列(
儿童:[
卡片(
颜色:颜色,白色,
形状:圆形矩形边框(
边界半径:边界半径。圆形(12.0),
),
子项:列(子项:[
列表砖(
标题:正文(
“${(snapshot.data.documents[index]['title'])}”,
风格:GoogleFonts.lato(
字体大小:20.0,
身高:1.2,
fontWeight:fontWeight.w500,
),
textAlign:textAlign.center,
),
字幕:世界其他地区(
mainAxisSize:mainAxisSize.max,
crossAxisAlignment:crossAxisAlignment.start,
儿童:[
材料按钮(
子项:文本(“共享文本”),
onPressed:()async=>wait _shareText(),
),
尺寸箱(高度:5.0),
ImageInput(),//显示调用的图像
从图像选择器到共享,它用于共享图像。
扩大(
子:文本(
'${(snapshot.data.documents[索引]
['subtitle'])},
textAlign:textAlign.right,
风格:GoogleFonts.lato(
字体大小:13.0,
fontWeight:fontWeight.w900,
fontStyle:fontStyle.italic,
颜色:颜色,蓝色,
),
),//副标题:文本
),
]//儿童
),//行
),//listtile
]),
),
],
),
),
交错文件生成器:(int索引)=>交错文件.fit(2),
);
}),
),
);
}//构建
}//类
我将ImageInput()类页面复制到主页中,因为我无法将图像和文本一起共享,我仍然在共享文本字段中看到文本和快照的“未定义”错误。同样的修正对文本不起作用,尽管它现在在同一页上。我做错了什么
MaterialButton(
child: Text('Send it!'),
onPressed: () async => await _shareImageAndText(snapshot, index),
),
---
Future<void> _shareImageAndText(snapshot, index) async {
try {
List<int> imageBytes = await _imageFile.readAsBytes();
var uint8List = Uint8List.fromList(imageBytes);
await Share.file('esys image', 'esys.jpg', uint8List, 'image/jpeg',
text: (snapshot.data.documents[index].data['title']) );
//text: 'My optional text.');
// (snapshot.data.documents[index].data['title']), 'text/plain');
} catch (e) {
print('error: $e');
}}
MaterialButton(
孩子:文本('Send it!'),
onPressed:()async=>wait _shareImageAndText(快照、索引),
),
---
Future\u shareImageAndText(快照、索引)异步{
试一试{
List imageBytes=wait_imageFile.readAsBytes();
var uint8List=uint8List.fromList(imageBytes);
等待Share.file('esys image','esys.jpg',uint8List',image/jpeg',
text:(snapshot.data.documents[index].data['title']);
//文本:“我的可选文本”。);
//(快照)
MaterialButton(
child: Text('Send it!'),
onPressed: () async => await _shareImageAndText(snapshot, index),
),
---
Future<void> _shareImageAndText(snapshot, index) async {
try {
List<int> imageBytes = await _imageFile.readAsBytes();
var uint8List = Uint8List.fromList(imageBytes);
await Share.file('esys image', 'esys.jpg', uint8List, 'image/jpeg',
text: (snapshot.data.documents[index].data['title']) );
//text: 'My optional text.');
// (snapshot.data.documents[index].data['title']), 'text/plain');
} catch (e) {
print('error: $e');
}}
class ImageInput extends StatefulWidget {
@override
_ImageInputState createState() => _ImageInputState();
}
class _ImageInputState extends State<ImageInput> {
File _imageFile;
void _getImage(BuildContext context, ImageSource source){
ImagePicker.pickImage(source: source, maxWidth: 200.0).then((File image){
setState((){
_imageFile = image;
});
Navigator.pop(context);
});
}
void _openImagePicker(BuildContext context) {
showModalBottomSheet(context: context, builder: (BuildContext context) {
return Container(
height: 180.0,
padding: EdgeInsets.all(10.0),
child: Column(
children: [
Text('Choose photo',
style:TextStyle(fontWeight: FontWeight.bold),),
SizedBox(height: 10.0),
FlatButton(
textColor: Theme.of(context).primaryColor,
child: Text('Use Camera'),
onPressed: () {
_getImage(context, ImageSource.camera);
},),
FlatButton(
textColor: Theme.of(context).primaryColor,child:
Text('Open Gallery'),
onPressed: () {
_getImage(context, ImageSource.gallery);
},)
]
),);
});
}
@override
Widget build(BuildContext context) {
return Column(
children: <Widget>[
OutlineButton(
onPressed: () {
_openImagePicker(context);
},
child:Row(
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
Icon(Icons.camera_alt),
SizedBox(
width:1.0,
),
// Text('Add Image'),
]
),//Row
),//outline button
SizedBox(height: 10.0),
_imageFile == null ? Text('Add a Pic') : Image.file(_imageFile,
fit: BoxFit.cover,
height: 200.0,
width: 200.0,
// width: MediaQuery.of(context).size.width,
alignment: Alignment.topCenter,
),
MaterialButton(
child: Text('Send it!'),
onPressed: () async => await _shareImageAndText(),
),
],
);
}
}
Future<void> _shareText(snapshot, index) async {
try {
Share.text('Share Text ',
(snapshot.data.documents[index].data['title']), 'text/plain');
} catch (e) {
print('error: $e');
}
}