BehaviorSubject of a type in angular

Question

Let's say I have a model User.

I want to create a BehaviorSubject of type User as below:

 private userSource = new BehaviorSubject<User>({});

With this statement I'm getting the following error:

  Argument of type '{}' is not assignable to parameter of type 'User'

Could anyone help me how define a BehaviorSubject of type User

Answer 1

new BehaviorSubject<User>({}) with this you have passed an initial value for the BehaviorSubject. Cause {} has no type detection, you get error.

You need to pass an User type. Provide properties for that type in the {} like

private userSource = new BehaviorSubject<User>({ /* properties */ });

If you don't need initial value. you can use ReplaySubject with replay count set to 1

new ReplaySubject<User>(1)

This will provide same functionality without initial value.

Answer 2

那是因为{}是一个对象与User（实际上它是一个空对象）没有相同的属性。

您可以通过强制转换{}为any：

new BehaviorSubject<User>({} as any);

Answer 3

您需要传递User类型。{}是一个初始值，不遵循 的架构/类型User。
如果您想传递一个空值，请使用nullexcept{}