我从 Firebase Storage 获取图像，使用相机拍照或从库中选择一张图像。当其中之一完成时，我有一个存储 Image 的类，以便在需要时使用它。
现在我需要将此图像上传到 Firebase Storage（修改后或新的都可以）。Firebase 允许我使用以下之一：putData 或 putFile，每个选项需要一个 Uint8List 或 File。
我该如何对我的 Image 进行操作，以便获取要上传的 File 或 Uint8List？
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作为解决方法，当我从 Firebase Storage 中检索图像时，我该如何获取其 File？
无论哪种方式，最终都需要提供正确的数据类型才能上传图像，无论是在开始时还是结束时获取 File。
当你使用图像选择器选择一张图片时，它会返回一个File对象，你可以使用await关键字等待用户选择文件，然后将其作为File对象存储。以下是示例代码，展示如何从图像选择器中获取文件并将其上传到Firebase。
FirebaseStorage _storage = FirebaseStorage.instance;
Future<Uri> uploadPic() async {
//Get the file from the image picker and store it
File image = await ImagePicker.pickImage(source: ImageSource.gallery);
//Create a reference to the location you want to upload to in firebase
StorageReference reference = _storage.ref().child("images/");
//Upload the file to firebase
StorageUploadTask uploadTask = reference.putFile(file);
// Waits till the file is uploaded then stores the download url
Uri location = (await uploadTask.future).downloadUrl;
//returns the download url
return location;
}
抱歉回复晚了，上面的答案有点旧，希望我的回答能对你有所帮助。以下代码示例将在以下依赖项上工作。
在问题中，它说如何在上传后检索它。您可以使用下载URL获取文件或图像，您可以下载它，或者将其显示在NetworkImage小部件上以向用户显示。我已经展示了如何获取下载URL。
pubspec.yaml
dependencies
image_picker: ^0.6.5
firebase_storage: ^3.1.5
Dart Code
//Creating a global Variable
StorageReference storageReference = FirebaseStorage.instance.ref();
File _image;
void getImage(){
_image = await ImagePicker.pickImage(source: ImageSource.gallery);
}
void addImageToFirebase(){
//CreateRefernce to path.
StorageReference ref = storageReference.child("yourstorageLocation/");
//StorageUpload task is used to put the data you want in storage
//Make sure to get the image first before calling this method otherwise _image will be null.
StorageUploadTask storageUploadTask = ref.child("image1.jpg").putFile(_image);
if (storageUploadTask.isSuccessful || storageUploadTask.isComplete) {
final String url = await ref.getDownloadURL();
print("The download URL is " + url);
} else if (storageUploadTask.isInProgress) {
storageUploadTask.events.listen((event) {
double percentage = 100 *(event.snapshot.bytesTransferred.toDouble()
/ event.snapshot.totalByteCount.toDouble());
print("THe percentage " + percentage.toString());
});
StorageTaskSnapshot storageTaskSnapshot =await storageUploadTask.onComplete;
downloadUrl1 = await storageTaskSnapshot.ref.getDownloadURL();
//Here you can get the download URL when the task has been completed.
print("Download URL " + downloadUrl1.toString());
} else{
//Catch any cases here that might come up like canceled, interrupted
}
}
想要选择图片（从相册、相机等中），你可以使用图片选择器 package。
然后获取文件形式的图片，就像这样：
//Get the file from the image picker and store it
final pickedFile = await picker.getImage(source: ImageSource.camera);
File image;
if (pickedFile != null) {
image = File(pickedFile.path);
} else {
print('No image selected.');
return;
}
然后检测您想要保存此文件图像的参考文献
FirebaseStorage storage = FirebaseStorage.instance;
//Create a reference to the location you want to upload to in firebase
StorageReference reference = storage.ref().child("profileImages/myImageUid");
最后开始上传并等待完成，然后获取图像的URL。
//Upload the file to firebase
StorageUploadTask uploadTask = reference.putFile(image);
StorageTaskSnapshot taskSnapshot = await uploadTask.onComplete;
// Waits till the file is uploaded then stores the download url
String url = await taskSnapshot.ref.getDownloadURL();
完整代码
FirebaseStorage storage = FirebaseStorage.instance;
File image;
try {
//Get the file from the image picker and store it
image = await ImagePicker.pickImage(source: ImageSource.gallery);
} on PlatformException catch (e) {
//PlatformException is thrown with code : this happen when user back with don't
//selected image or not approve permission so stop method here
// check e.code to know what type is happen
return;
}
//Create a reference to the location you want to upload to in firebase
StorageReference reference =
storage.ref().child("profileImages/${user.id}");
//Upload the file to firebase
StorageUploadTask uploadTask = reference.putFile(image);
StorageTaskSnapshot taskSnapshot = await uploadTask.onComplete;
// Waits till the file is uploaded then stores the download url
String url = await taskSnapshot.ref.getDownloadURL();
同时，有一个库可以帮助您...
该库名为firebase_picture_uploader，可以像这样使用（节选自源代码）：
new PictureUploadWidget(
onPicturesChange: profilePictureCallback,
initialImages: _profilePictures,
settings: PictureUploadSettings(onErrorFunction: onErrorCallback),
buttonStyle: const PictureUploadButtonStyle(),
buttonText: 'Upload Picture',
enabled: true,
)
Firebase图片上传示例：
ImagePicker imagePicker = ImagePicker();
File file;
String imageUrl;
// 图片选择器
Future pickImageCamera() async {
var image = await imagePicker.pickImage(source: ImageSource.camera);
if (image != null) {
setState(() {
file = File(image.path);
});
}
}
// 将选定的图像上传到FireStore
uploadProfileImage() async {
Reference reference = FirebaseStorage.instance
.ref()
.child('profileImage/${Path.basename(file.path)}');
UploadTask uploadTask = reference.putFile(file);
TaskSnapshot snapshot = await uploadTask;
imageUrl = await snapshot.ref.getDownloadURL();
print(imageUrl);
}
当您从相册或相机选择图像时，只需使用以下函数获取带有扩展名的文件名：
basename(image.path)
import 'package:image_picker/image_picker.dart';
import 'package:path/path.dart';
import 'package:firebase_storage/firebase_storage.dart';
代码：
upload() async {
//pick image use ImageSource.camera for accessing camera.
File image = await ImagePicker.pickImage(source: ImageSource.gallery);
//basename() function will give you the filename
String fileName = basename(image.path);
//passing your path with the filename to Firebase Storage Reference
StorageReference reference =
FirebaseHelper.firebaseStorage().child("your_path/$fileName");
//upload the file to Firebase Storage
StorageUploadTask uploadTask = reference.putFile(image);
//Snapshot of the uploading task
StorageTaskSnapshot taskSnapshot = await uploadTask.onComplete;
}
ImagePicker可以帮助我们从相册/相机中获取文件，并使用FirebaseStorage上传它。 getDownloadURL()方法可以给我们提供已上传到Firebase的下载链接。
Future uploadImageToFirebase(BuildContext context) async {
final picker = ImagePicker();
final pickedFile = await picker.getImage(source: ImageSource. gallery);
File image = new File(pickedFile.path);
var reference = FirebaseStorage.instance.ref().child('last_image/car5'); // Modify this path/string as your need
StorageUploadTask uploadTask = reference.putFile(file);
StorageTaskSnapshot taskSnapshot = await uploadTask.onComplete;
taskSnapshot.ref.getDownloadURL().then(
(value) => print("Download URL: $value"),
);
}
回答晚了，但这可能会对某些人有所帮助。 以下是我获取图库中的图像并将其上传到Firebase的方法。希望您会喜欢这种方法。
XFile? image;
ImagePicker().pickImage(source: ImageSource.gallery,).then((value) {
setState(() {
image = value;
});
});
FirebaseStorage.instance.ref("desiredPathForImage/").putFile(File(image!.path))
.then((TaskSnapshot taskSnapshot) {
if (taskSnapshot.state == TaskState.success) {
print("Image uploaded Successful");
// Get Image URL Now
taskSnapshot.ref.getDownloadURL().then(
(imageURL) {
print("Image Download URL is $imageURL");
});
}
else if (taskSnapshot.state == TaskState.running) {
// Show Prgress indicator
}
else if (taskSnapshot.state == TaskState.error) {
// Handle Error Here
}
});
firebase_core: ^1.10.3
firebase_analytics: ^9.0.0
firebase_messaging: ^11.2.1
firebase_storage: ^10.2.4
image_picker: ^0.8.4+4
import 'package:firebase_storage/firebase_storage.dart' as firebase_storage;
Future<void> uploadImageToFirebase(XFile? image) async {
Directory appDocDir = await getApplicationDocumentsDirectory();
String filePath = 'directoryName/${image?.path.split("/").last}';
File file = File(image?.path ?? "");
try {
TaskSnapshot uploadTask = await firebase_storage.FirebaseStorage.instance
.ref(filePath)
.putFile(file);
String? url = await uploadTask.ref.getDownloadURL();
print("download url : $url");
vm.pickedImages[index] = url;
} on FirebaseException catch (e) {
// e.g, e.code == 'canceled'
}
}
uploadTask中不存在未来（future）。 - user3836415