如何从另一个Dart文件中调用一个方法？

huangapple
go评论91阅读模式
英文:

how to call a method from another dart file?

问题

在我的程序中，我想要在名为getPhoto()的方法内调用相同路径，以从其他文件或StatefulWidget获取"like"字段的路径。

英文:

in my programme i want to call the same path inside a methode called getPhoto()=>upload(statefulwidget) to other file or statefulwidget

  1. Future getPhoto() async{
  3. FirebaseFirestore fearbase = FirebaseFirestore.instance;
  5.  Reference ref=FirebaseStorage.instance
  6.  .ref()
  7.  .child("${widget.user}/ProfileData")
  8.  .child("Url_$postId");
  10.  await ref.putFile(file!);
  11. downloadUrl=await ref.getDownloadURL();
  13. //  upload image to firestore
  14. var list=[];
  15. await fearbase.collection("users").doc(widget.user)
  16. .collection("PostData").doc(ido)
  17. .set({"PostUrl":downloadUrl,"ownerName":loggedInUser.username,"userId":loggedInUser.uid,"timestemp":postId,"PostId":ido,"like":FieldValue
  18. .arrayUnion(list)})
  19. .whenComplete(() => Fluttertoast.showToast(msg: "Image Uploaded successfully .i."));
  20. // .then((DocumentReference ido) => ido.update({"PostId":ido.id}))
  22. }

more specifically i want to get like field path from the other file

答案1

得分: 2

你可以使用回调函数来解决这个问题。

在使用时，可以按照以下方式传递函数：

  1. getPhoto().then(upload);

或者

  1. final downloadUrl = await getPhoto();
  2. await upload(downloadUrl);
英文:

You can use callback function to solve this.

  1. Future<String> getPhoto() async {
  2.   Reference ref = FirebaseStorage.instance
  3.       .ref()
  4.       .child("${widget.user}/ProfileData")
  5.       .child("Url_$postId");
  6.   await ref.putFile(file!);
  7.   return await ref.getDownloadURL();
  8.   //  upload image to firestore
  9.   
  10.   // .then((DocumentReference ido) => ido.update({"PostId":ido.id}))
  11. }
  13. Future upload(String downloadUrl) async {
  14.   FirebaseFirestore firebase = FirebaseFirestore.instance;
  15.   var list = [];
  16.   await firebase.collection("users").doc(widget.user)
  17.       .collection("PostData").doc(ido)
  18.       .set({
  19.     "PostUrl": downloadUrl,
  20.     "ownerName": loggedInUser.username,
  21.     "userId": loggedInUser.uid,
  22.     "timestemp": postId,
  23.     "PostId": ido,
  24.     "like": FieldValue
  25.         .arrayUnion(list)
  26.   })
  27.       .whenComplete(() => Fluttertoast.showToast(msg: "Image Uploaded successfully .i."));
  28. }

In usage, you can pass the function as follows

  1.   getPhoto().then(upload);

Or

  1.   final downloadUrl = await getPhoto();
  2.   await upload(downloadUrl);

答案2

得分: 1

有多种方法可以做到这一点。

但简单的方法是创建一个类并在类内定义这个方法。

  1. class Demo {
  2.     static void getPhoto() {
  3.         print("photo");
  4.     }
  5. }

然后你可以像这样访问它

  1. Demo.getPhoto()
英文:

There are multiple ways to do this.

But the simple one is you can create a class and define this method within the class.

  1. class Demo {
  2.     static void getPhoto() {
  3.         print("photo");
  4.     }
  5. }

Then your can access it like

  1. Demo.getPhoto()

huangapple
  • 本文由 发表于 2023年2月18日 21:43:11
  • 转载请务必保留本文链接：https://go.coder-hub.com/75493742.html
  • dart
  • firebase
  • flutter
匿名

发表评论

匿名网友

:?: :razz: :sad: :evil: :!: :smile: :oops: :grin: :eek: :shock: :???: :cool: :lol: :mad: :twisted: :roll: :wink: :idea: :arrow: :neutral: :cry: :mrgreen:

确定