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Rx合并阻止初始值

reactive system.reactive

Syntax · 技术社区 · 7 年前

使用以下代码,我期望:

first - OnNext(a)  <-- initial on subscribe
first - OnNext(c)  <-- initial on subscribe
first - OnNext(b)  <-- result of OnNext
second - OnNext(b) <-- initial on subscribe
second - OnNext(c) <-- initial on subscribe
first - OnNext(d)  <-- result of OnNext
second - OnNext(d) <-- result of OnNext

first - OnNext(b)  <-- result of OnNext
first - OnNext(d)  <-- result of OnNext
second - OnNext(d) <-- result of OnNext

代码:

var connection1 = new BehaviorSubject<string>("a");
var connection2 = new BehaviorSubject<string>("c");
var connection = Observable.Merge(connection1, connection2).StartWith(connection1.Value, connection2.Value).Publish();
connection.Connect();
connection.SubscribeLogger("first");
connection1.OnNext("b");
connection.SubscribeLogger("second");
connection2.OnNext("d");

3 回复 | 直到 7 年前

Eric Olsson 7 年前

Here 是一个链接,用于解释连接的可观察对象背后的一般理想(通过调用 Connect() 在合并输出上。

什么时候 Connect() 被调用时,合并的输出将其发布的值发送给订阅者(此时没有,因此初始 a 和 c

然后 first 订阅和后续调用 connection1.OnNext("b"); b 由 第一

second 订阅,但因为它是一个连接的可观察对象, 第二 将仅接收订阅后发布的值。因此 connection2.OnNext("d"); 第一 第二 .

Shlomo 7 年前

var connection1 = new BehaviorSubject<string>("a");
var connection2 = new BehaviorSubject<string>("c");
var connection = Observable.Merge(connection1, connection2).StartWith(connection1.Value, connection2.Value).Publish();
connection.SubscribeLogger("first"); //Flip order, put Subscribe before connect
connection.Connect();
connection1.OnNext("b");
connection.SubscribeLogger("second");
connection2.OnNext("d");

first - OnNext(a) //From the start with
first - OnNext(c) //From the start with
first - OnNext(a) //From the behavior subject
first - OnNext(c) //From the behavior subject
first - OnNext(b)
first - OnNext(d)
second - OnNext(d)

Publish / Connect ,如果您想获得任何“on subscribe”值,则需要在连接之前进行订阅。在你之后 ,任何Cold或“on subscribe”值都不会到达新订阅者。

Syntax 7 年前

这段代码似乎实现了我想要的功能:

var subject1 = new BehaviorSubject<string>("a");
var subject2 = new BehaviorSubject<string>("c");
// Use separate merged observables to simulate multiple calls to getter
// under the hood which builds the new merged view of the subjects.
var connection = subject1.Merge(subject2);
var connection2 = subject1.Merge(subject2);

connection.SubscribeLogger("first");
subject1.OnNext("b");
connection2.SubscribeLogger("second");
subject2.OnNext("d");

输出:

first - OnNext(a)
first - OnNext(c)
first - OnNext(b)
second - OnNext(b)
second - OnNext(c)
first - OnNext(d)
second - OnNext(d)