Question

windowWhen

函数签名: windowWhen(closingSelector: function(): Observable): Observable

在提供的时间帧处关闭窗口，并发出从源 observable 中收集的值的 observable 。

示例

示例 1: 根据定时器开启和关闭窗口

( StackBlitz | jsBin | jsFiddle )

// RxJS v6+
import { interval, timer } from 'rxjs';
import { windowWhen, tap, mergeAll } from 'rxjs/operators';

// 立即发出值，然后每秒发出值
const source = timer(0, 1000);
const example = source.pipe(
  // 每5秒关闭窗口并发出从源 observable 中收集的值的 observable
  windowWhen(() => interval(5000)),
  tap(_ => console.log('NEW WINDOW!'))
);

const subscribeTwo = example
  .pipe(
    // 窗口发出嵌套的 observable
    mergeAll()
    /*
      输出:
      "NEW WINDOW!"
      0
      1
      2
      3
      4
      "NEW WINDOW!"
      5
      6
      7
      8
      9
    */
  )
  .subscribe(val => console.log(val));

其他资源

• windowWhen :newspaper: - 官方文档

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源码: https://github.com/ReactiveX/rxjs/blob/master/src/internal/operators/windowWhen.ts