下图片异步变同步

佚名 6年前 (2019-05-11) 随笔 863人围观抢沙发百度已收录

var fs = require('fs');
var request = require("request");
var src = "https://...../activity/img/hb11.jpg";

const last = src.lastIndexOf('/')


down2img();

async function down2img(){
   let ret =  await downImg(src,1);
   console.log('down 1 over' + ret);
   ret =  await downImg(src,2);
   console.log('down 1 over' + ret);
}


function downImg(url,para) {
    return new Promise((resolve, reject) => {
        // 块方式写入文件
        var writeStream = fs.createWriteStream(para+'hb11.jpg');
        var readStream = request(url);
        readStream.pipe(writeStream);

        writeStream.on('error', (err) => { reject(err); });
        writeStream.on('finish', () => { 
            console.log("文件写入成功");
            writeStream.end();
            resolve(true);
            // 括号里面的是返回值
        });
    });
}
  


/*
var writeStream = fs.createWriteStream('hb11.jpg');
var readStream = request(src)
readStream.pipe(writeStream);
readStream.on('end', function() {
    console.log('文件下载成功');
});
readStream.on('error', function() {
    console.log("错误信息:" + err)
})

writeStream.on("finish", function() {
    console.log("文件写入成功");
    writeStream.end();
});
*/

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图片缩放

var fs = require('fs'); var gm = require('gm'); gm('./1hb11.jpg') .resize(50, 50,"!") .write('./50.jpg', function (err) { if (!err) console.log('done'); else console.log(err); });