cant get downloadUrl after upload the image to FireBase in Flutter - flutter

Question

after i upload my image to Firebase i cant get it's download url. i wanna get it to show uploaded pics in other pages. here is my codes:
import 'dart:io';
import 'package:firebase/GetPic.dart';
import 'package:firebase_storage/firebase_storage.dart';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
class ImageUploadPage extends StatefulWidget {
#override
State<StatefulWidget> createState() {
// TODO: implement createState
return ImageUploadPageState();
}
}
class ImageUploadPageState extends State{
TextEditingController _control= TextEditingController();
File _selectedImage;
final _formKey = GlobalKey<FormState>();
#override
Widget build(BuildContext context) {
// TODO: implement build
return Scaffold(
appBar: AppBar(
title: Text("IMAGE UPLOAD PAGE"),
actions: [
IconButton(
icon: Icon(Icons.arrow_right_alt), onPressed: (){
Navigator.push(context, MaterialPageRoute(
builder: (context)=>GetPic(),));
}),
],
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
RaisedButton(
child: Text("Galeriden resim seçin"),
onPressed: (){_selectImage();}),
Expanded(
child: _selectedImage== null ?
Text("there is no pic"): Image.file(_selectedImage)),
Form(
key: _formKey,
child: Padding(
padding: const EdgeInsets.all(25.0),
child: TextFormField(
controller: _control,
decoration: InputDecoration(
labelText: "image's name",
labelStyle: TextStyle(color: Colors.greenAccent)
),
style: TextStyle(fontStyle: FontStyle.italic, fontSize: 17),
),
),
),
RaisedButton(
child: Text("Upload image"),
onPressed: (){_uploadImage();}),
]
),
),
);
}
void _selectImage() async {
var _iamge= await ImagePicker.pickImage(source: ImageSource.gallery);
_selelctedImage= _image;
setState(() {});
}
Future<String> _uploadImage() async {
_formKey.currentState.save();
String imageFileName = _control.text;
final Reference ref = await FirebaseStorage.instance.ref().child("deneme").child("resimler").child(imageFileName);
UploadTask uploadTask = ref.putFile(_selectedImage);
var downloadUrl = await (await uploadTask.snapshot).ref.getDownloadURL();
debugPrint(downloadUrl.toString());
return downloadUrl.toString();
}
}
i have TextFormField that gives image's name. if i upload an image(same or different) with same name i can get last one's donwload url normally. in my opinion image's name that i uploaded cant be seen at first try unlike to second try. so i am fail to get download url at first try and success at second try. i hope i could tell my problem clearly. i will be so glad if somebody helps.
Here is my android/build.gradle
buildscript {
ext.kotlin_version = '1.3.50'
repositories {
google() // Google's Maven repository
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:4.0.2'
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
classpath 'com.google.gms:google-services:4.3.4'
classpath 'com.google.firebase:firebase-crashlytics-gradle:2.4.1'
}
}
allprojects {
repositories {
google() // Google's Maven repository
jcenter()
}
}
rootProject.buildDir = '../build'
subprojects {
project.buildDir = "${rootProject.buildDir}/${project.name}"
}
subprojects {
project.evaluationDependsOn(':app')
}
task clean(type: Delete) {
delete rootProject.buildDir
}
Here is my app/build.gradle
def localProperties = new Properties()
def localPropertiesFile = rootProject.file('local.properties')
if (localPropertiesFile.exists()) {
localPropertiesFile.withReader('UTF-8') { reader ->
localProperties.load(reader)
}
}
def flutterRoot = localProperties.getProperty('flutter.sdk')
if (flutterRoot == null) {
throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
}
def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
if (flutterVersionCode == null) {
flutterVersionCode = '1'
}
def flutterVersionName = localProperties.getProperty('flutter.versionName')
if (flutterVersionName == null) {
flutterVersionName = '1.0'
}
apply plugin: 'com.android.application'
apply plugin: 'com.google.gms.google-services'
apply plugin: 'kotlin-android'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
apply plugin: 'com.google.firebase.crashlytics'
android {
compileSdkVersion 29
sourceSets {
main.java.srcDirs += 'src/main/kotlin'
}
lintOptions {
disable 'InvalidPackage'
}
defaultConfig {
// TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
applicationId "meb.firebase"
minSdkVersion 16
targetSdkVersion 29
versionCode flutterVersionCode.toInteger()
versionName flutterVersionName
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
multiDexEnabled true
}
buildTypes {
release {
// TODO: Add your own signing config for the release build.
// Signing with the debug keys for now, so `flutter run --release` works.
signingConfig signingConfigs.debug
}
}
}
flutter {
source '../..'
}
dependencies {
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.4.20"
testImplementation 'junit:junit:4.13.1'
androidTestImplementation 'androidx.test:runner:1.3.0'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
implementation platform('com.google.firebase:firebase-bom:26.1.0')
implementation 'com.android.support:multidex:1.0.3'
implementation "com.google.firebase:firebase-messaging:20.2.4"
}
and al last Here is my error message:
E/flutter (17095): [ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: [firebase_storage/object-not-found] No object exists at the desired reference.
E/flutter (17095): #0 MethodChannelReference.getDownloadURL (package:firebase_storage_platform_interface/src/method_channel/method_channel_reference.dart:57:7)
E/flutter (17095): <asynchronous suspension>
E/flutter (17095): #1 Reference.getDownloadURL (package:firebase_storage/src/reference.dart:94:48)
E/flutter (17095): #2 ImageUploadPageState._resimYukle (package:firebase/ImageUploadPage.dart:83:61)
E/flutter (17095): <asynchronous suspension>
E/flutter (17095): #3 ImageUploadPageState.build.<anonymous closure> (package:firebase/ImageUploadPage.dart:62:31)
E/flutter (17095): #4 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:993:19)
E/flutter (17095): #5 _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:1111:38)
E/flutter (17095): #6 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:183:24)
E/flutter (17095): #7 TapGestureRecognizer.handleTapUp (package:flutter/src/gestures/tap.dart:598:11)
E/flutter (17095): #8 BaseTapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:287:5)
E/flutter (17095): #9 BaseTapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:222:7)
E/flutter (17095): #10 PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:476:9)
E/flutter (17095): #11 PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:77:12)
E/flutter (17095): #12 PointerRouter._dispatchEventToRoutes.<anonymous closure> (package:flutter/src/gestures/pointer_router.dart:122:9)
E/flutter (17095): #13 _LinkedHashMapMixin.forEach (dart:collection-patch/compact_hash.dart:377:8)
E/flutter (17095): #14 PointerRouter._dispatchEventToRoutes (package:flutter/src/gestures/pointer_router.dart:120:18)
E/flutter (17095): #15 PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:106:7)
E/flutter (17095): #16 GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:358:19)
E/flutter (17095): #17 GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:338:22)
E/flutter (17095): #18 RendererBinding.dispatchEvent (package:flutter/src/rendering/binding.dart:267:11)
E/flutter (17095): #19 GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:295:7)
E/flutter (17095): #20 GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:240:7)
E/flutter (17095): #21 GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:213:7)
E/flutter (17095): #22 _rootRunUnary (dart:async/zone.dart:1206:13)
E/flutter (17095): #23 _CustomZone.runUnary (dart:async/zone.dart:1100:19)
E/flutter (17095): #24 _CustomZone.runUnaryGuarded (dart:async/zone.dart:1005:7)
E/flutter (17095): #25 _invoke1 (dart:ui/hooks.dart:265:10)
E/flutter (17095): #26 _dispatchPointerDataPacket (dart:ui/hooks.dart:174:5)
E/flutter (17095):

Answer 1

Just await the result of putFile to wait until the upload is complete before requesting the URL.
await ref.putFile(_selectedImage);
var downloadUrl = await ref.getDownloadURL();
debugPrint(downloadUrl);
I suggest reviewing the documentation for more details.