Node.js 可写流拆线事件
原文:https://www . geesforgeks . org/node-js-written-stream-unpip-event/
可写流中的“unpip”事件是在可读流上调用 stream.unpipe()方法时发出的,方法是将该可写流从其目标集合中分离出来。
语法:
Event: 'unpipe'
返回值:如果正在调用 unpipe()方法,则发出此事件,否则不发出。
以下示例说明了在 Node.js 中使用“取消固定”事件:
例 1:
// Node.js program to demonstrate the
// unpipe event
// Accessing fs module
var fs = require("fs");
// Create a readable stream
var readable = fs.createReadStream('input.txt');
// Create a writable stream
var writable = fs.createWriteStream('output.txt');
// Handling unpipe event
writable.on("unpipe", readable => {
console.log("Unpiped!");
});
// Calling pipe method
readable.pipe(writable);
// Calling unpipe method
readable.unpipe(writable);
console.log("Program Ended...");
输出:
Unpiped!
Program Ended...
例 2:
// Node.js program to demonstrate the
// unpipe event
// Accessing fs module
var fs = require("fs");
// Create a readable stream
var readable = fs.createReadStream('input.txt');
// Create a writable stream
var writable = fs.createWriteStream('output.txt');
// Handling unpipe event
writable.on("unpipe", readable => {
console.log("Unpiped!");
});
console.log("Program Ended...");
输出:
Program Ended...
因此,这里不调用 unpipe()函数,因此不发出 unpipe 事件。
参考:T2】https://nodejs.org/api/stream.html#stream_event_unpipe
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