首先要下载对应的插件包；

gulp-less包：cnpm install gulp-less --save-dev     

gulp-connect包：cnpm install gulp-connect--save-dev

gulp-minify-css包：cnpm install gulp-minify-css --save-dev

var gulp=require('gulp'),    gulp_less=require('gulp-less'),    gulp_connect=require('gulp-connect'),    gulp_minify_css=require('gulp-minify-css');//在一个任务中【执行多个任务】gulp.task('serves',function () {    //创建一个服务器，端口默认是8080    gulp_connect.server({        //root：根目录        root:'web',        livereload:true    });    //动态监听    gulp.watch('web/**/*.*',['reload','less']);});//部署动作命令-reloadgulp.task('reload',function () {    gulp.src('web/**/*.*')        .pipe(gulp_connect.reload());});//部署动作-lessgulp.task('less',function () {    gulp.src('web/less/*.less')        .pipe(gulp_less())        .pipe(gulp_minify_css())        .pipe(gulp.dest('web/css/'))});