Node.js writeStream.clearScreenDown()用法及代码示例

writeStream.clearScreenDown()方法是tty模块中类WriteStream的内置应用程序编程接口，用于从当前光标向下清除此写流对象。

用法:

writeStream.clearScreenDown([callback])

参数：此方法不接受任何参数，但会调用回调函数。

返回值：如果写入对象为clear，则此方法返回布尔值true，否则返回false。

范例1： 文件名：index.js

// Node.js program to demonstrate the 
// writeStream.clearScreenDown() method 
  
// Importing dgram module 
var dgram = require('dgram'); 
  
// Creating and initializing client 
// and server socket 
var client = dgram.createSocket("udp4"); 
var server = dgram.createSocket("udp4"); 
  
// Handling the message event 
server.on("message", function (msg) { 
  
  // Creating and initializing a 
  // WriteStream object 
  let WriteStream = process.stdout; 
  
  // Clearing the write stream object 
  // by using clearScreenDown() API 
  const col = WriteStream.clearScreenDown(); 
  
  // Displaying the result 
  process.stdout.write(msg + col); 
  
  // Exiting process 
  process.exit(); 
}) 
// Binding server with port 
.bind(1234, () => { 
}); 
  
// Client sending message to server 
client.send("The line is clear:-  ",  
        0, 26, 1234, "localhost");

输出：

The line is clear:-  true

范例2： 文件名：index.js

// Node.js program to demonstrate the 
// writeStream.clearScreenDown() method 
  
// Creating and initializing a  
// WriteStream object 
let WriteStream = process.stdout; 
  
// Clearing the write stream object 
// by using clearScreenDown() API 
const col = WriteStream.clearScreenDown(); 
  
// Displaying the result 
console.log("The write stream object"
    + " is clear:-  " + col);

使用以下命令运行index.js文件：

node index.js

输出：

The write stream object is clear:-  true

参考： https://nodejs.org/dist/latest-v12.x/docs/api/tty.html#tty_writestream_clearscreendown_callback

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注：本文由纯净天空筛选整理自RohitPrasad3大神的英文原创作品 Node.js writeStream.clearScreenDown() Method。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。