Question

windowCount

函数签名: windowCount(windowSize: number, startWindowEvery: number): Observable

源 observable 中的值的 observable，每次发出N个值(N由参数决定)。

示例

示例 1: 每发出x个项就开启一个新窗口

( StackBlitz | jsBin | jsFiddle )

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

// 每1秒发出值
const source = interval(1000);
const example = source.pipe(
  // 每发出4个值就开启新窗口
  windowCount(4),
  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
      "NEW WINDOW!"
      4
      5
      6
      7
    */
  )
  .subscribe(val => console.log(val));

其他资源

• windowCount :newspaper: - 官方文档

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