Question

执行以下代码时，只执行async.series的第一个函数。

var fs = require("fs");
var async = require("async");
var buffer = new Buffer(10);
var read = "";
var readByt;
async.series([      
    function(callback) {
         console.log("console: 1");
    },
    function (callback){
        console.log("console: 2");
    }
],function(){});

输出如下：

c:\>node fr.js
}}}c:/log.txt
File closed successfully.

如果按以下方式编辑以下内容：

var fs = require("fs");
var async = require("async");
var buffer = new Buffer(10);
var read = "";
var readByt;
async.series([
    function(callback) {
         console.log("test");
    },
    function (callback){
        console.log("console: 1");
    }
   function (callback){
        console.log("console: 2");
    }
],function(){});

输出变化如下：

c:\>node fr.js
test

如何让async.series中的所有函数执行？

Answer 1

我认为你需要调用函数数组中提供的callback参数来指示async模块调用下一个函数。

Answer 2

var fs = require("fs");
var async = require("async");
var buffer = new Buffer(10);
var read = "";
var readByt;
async.series([      
    function(callback) {
        fs.open('c:/ab.txt', 'r+', function(err, fd) {
            fs.read(fd, buffer, 0, buffer.length, 0, function(err, bytes){
                read = buffer.slice(0, bytes).toString();
                readByt = bytes;        
                console.log("}}}"+read);
                fs.close(fd, function(err){
                    if (err){
                    console.log(err);
                    } 
                    console.log("File closed successfully.");           
                })
            })
        })

     //invoke here for continue and to break use callback(false);
     callback()

    },
    function (callback){
        console.log("console:"+read);
        console.log("console:"+read.substr(read.length-1));
        console.log("console:"+buffer.slice(0, readByt).toString());
    }
],function(){});

nodejs：Async.series只执行第一个函数并停止

2 个答案: