vue 生命周期
1，beforeCreate 组件刚刚被创建
2，created 组件创建完成
3，beforeMount 挂载之前
4，mounted 挂载之后
5，beforeDestory 组件销毁前调用
6，destoryed 组件销毁后调用
<template>
<h3>我爱你</h3>
</template>
<script>
export default{
data(){
return{
}
},
beforeCreate(){
console.log("beforeCreate");
},
created(){
console.log('created');
},
beforeMount(){
console.log('beforeMount');
},
mounted(){
console.log('mounted');
},
beforeDestory(){
console.log('beforeDestory');
},
destoryed(){
console.log('destoryed');
}
}
</script>
在Vue.js的生命周期中，可以分为6个阶段，也就是6个函数代表6个阶段，不管顺序如何变，还是会按照以下顺序去执行代码：
beforeCreate（创建前）——>created（创建后）——>beforeMount(载入前)——>mounted（载入后）——>beforeDestroy（销毁前）——>destroyed（销毁后）
卸载命令：
卸载vue-cli : npm uninstall vue-cli -g
安装vue-cli : npm install --global vue-cli
卸载cnpm : npm uninstall cnpm -g
安装cnpm : npm install
---------以下是安装vue项目完整步骤，一：-----------
安装npm步骤：（其实直接可以使用Git软件里面的命令控制面板安装查看，和安装 vue 各种执行文件）
1，Win+R 打开命令面板---输入cmd，回车---在命令面板输入以下命令来查看相关软件的版本号:
a, node -v + 回车 直接百度安装node.js软件后再到命令控制面板查看版本号
v10.16.2
b, npm -v + 回车 安装完成node.js(npm是集成在node.js中的，如果nodejs安装成功，则npm也安装成功)，
如果有，则会出现版本号，否则就没有安装。
6.9.0
c, vue + 回车(这里是直接输入vue,没有-V) 安装成功后显示如下：（通过：npm install --global vue-cli 来安装的）
$ vue
Usage: vue <command> [options]
Options:
-V, --version output the version number <!-- 这里的V 一定是大写，才会出现版本号 -->
-h, --help output usage information
Commands:
init generate a new project from a template
list list available official templates
build prototype a new project
create (for v3 warning only)
help [cmd] display help for [cmd]
2，先安装node.js 下载安装指定盘符即可。
3，win+R 进入命令控制面板 输入：path + 回车，安装成功会在下方显示node.js，可以仔细查找以下。
path 为可执行文件显示或设置搜索路径(在命令控制面中输入：help，会出现一系列命令)
4，也可以直接输入 node -v 查看是否有安装成功，成功就会显示版本号。
5，安装:Git工具。
进入某个盘符，直接输入 D: + 回车即可。
但是如果要进入：D:\前端开发\HTML\组件化网页开发 步骤二 2-3 创建XMLHttpRequest对象\Ajax\register\img
这样的路径，使用手写方式就很麻烦了，所以需要一个工具来帮忙，
这个工具就是：官网：https://git-scm.com/ 点击 DownLoads --- 选择相应系统的版本下载安装即可。
安装完成，直接打开指定的文件夹，右击---选择---git bash here 进入到此处的子程序
马上就跳出一个在该路径下面的 node.js命令面板----就可以直接进行代码编写。
5，安装好node.js后，npm具体代码安装
---------步骤二：(Win + R)在控制面板中输入以下命令行-----------
#全局安装 vue-cli 分为两种情况：
一，使用npm，访问国外网站。
输入：npm install --global vue-cli
(这里的npm是访问国外的网站，下载速度很慢。所以，可以使用淘宝镜像的cnpm)
回车等待下载完成，显示如下：
韦德君@LAPTOP-AKTJNVLT MINGW64 /d/泉州时代/学习/vue.js
$ npm install --global vue-cli
npm WARN deprecated [email protected]: This package has been deprecated in favour of @vue/cli
npm WARN deprecated [email protected]: CoffeeScript on NPM has moved to "coffeescript" (no hyphen)
C:\Users\30467\AppData\Roaming\npm\vue -> C:\Users\30467\AppData\Roaming\npm\node_modules\vue-cli\bin\vue
C:\Users\30467\AppData\Roaming\npm\vue-list -> C:\Users\30467\AppData\Roaming\npm\node_modules\vue-cli\bin\vue-list
C:\Users\30467\AppData\Roaming\npm\vue-init -> C:\Users\30467\AppData\Roaming\npm\node_modules\vue-cli\bin\vue-init
+ [email protected]
added 241 packages from 206 contributors in 150.212s
韦德君@LAPTOP-AKTJNVLT MINGW64 /d/泉州时代/学习/vue.js
二，使用国内网站，淘宝的镜像。
不使用上面国外的npm，改为使用使用淘宝npm镜像的步骤：
1，输入：npm install -g cnpm --registry=https://registry.npm.taobao.org/ + 按回车
显示如下；
韦德君@LAPTOP-AKTJNVLT MINGW64 /d/泉州时代/学习/vue.js
$ npm install -g cnpm --registry=https://registry.npm.taobao.org/
C:\Users\30467\AppData\Roaming\npm\cnpm -> C:\Users\30467\AppData\Roaming\npm\node_modules\cnpm\bin\cnpm
+ [email protected]
added 680 packages from 928 contributors in 121.079s
<!-- 如果是重复安装，那么就是进行更新操作，最后一局可能会变成：
updated 2 packages in 74.538s -->
2，输入： cnpm install --global vue-cli + 回车。
显示如下：才算成功安装
韦德君@LAPTOP-AKTJNVLT MINGW64 /d/泉州时代/学习/vue.js
cnpm install --global vue-cli
Downloading vue-cli to C:\Users\30467\AppData\Roaming\npm\node_modules\vue-cli_tmp
Copying C:\Users\30467\AppData\Roaming\npm\node_modules\vue-cli_tmp\[email protected]@vue-cli to C:\Users\30467\AppData\Roaming\npm\node_modules\vue-cli
Installing vue-cli's dependencies to C:\Users\30467\AppData\Roaming\npm\node_modules\vue-cli/node_modules
[1/20] commander@^2.9.0 installed at node_modules\[email protected]@commander
[2/20] ora@^1.3.0 installed at node_modules\[email protected]@ora
[3/20] minimatch@^3.0.0 installed at node_modules\[email protected]@minimatch
[4/20] multimatch@^2.1.0 installed at node_modules\[email protected]@multimatch
[5/20] rimraf@^2.5.0 existed at node_modules\[email protected]@rimraf
[6/20] consolidate@^0.14.0 installed at node_modules\[email protected]@consolidate
[7/20] chalk@^2.1.0 installed at node_modules\[email protected]@chalk
[8/20] semver@^5.1.0 installed at node_modules\[email protected]@semver
[9/20] tildify@^1.2.0 installed at node_modules\[email protected]@tildify
[10/20] [email protected] installed at node_modules\[email protected]@uid
[11/20] user-home@^2.0.0 installed at node_modules\[email protected]@user-home
[12/20] read-metadata@^1.0.0 installed at node_modules\[email protected]@read-metadata
[13/20] [email protected] existed at node_modules\[email protected]@coffee-script
[14/20] validate-npm-package-name@^3.0.0 installed at node_modules\[email protected]@validate-npm-package-name
[15/20] metalsmith@^2.1.0 installed at node_modules\[email protected]@metalsmith
[16/20] handlebars@^4.0.5 installed at node_modules\[email protected]@handlebars
[17/20] download-git-repo@^1.0.1 installed at node_modules\[email protected]@download-git-repo
[18/20] request@^2.67.0 installed at node_modules\[email protected]@request
[19/20] async@^2.4.0 installed at node_modules\[email protected]@async
[20/20] inquirer@^6.0.0 installed at node_modules\[email protected]@inquirer
deprecate [email protected] › [email protected] › coffee-script@^1.12.4 CoffeeScript on NPM has moved to "coffeescript" (no hyphen)
Recently updated (since 2019-11-05): 2 packages (detail see file C:\Users\30467\AppData\Roaming\npm\node_modules\vue-cli\node_modules\.recently_updates.txt)
2019-11-07
→ [email protected] › [email protected] › glob@^7.1.3(7.1.6) (06:07:44)
2019-11-06
→ [email protected] › uglify-js@^3.1.4(3.6.8) (16:49:20)
All packages installed (239 packages installed from npm registry, used 28s(network 27s), speed 191.86kB/s, json 223(438.7kB), tarball 4.55MB)
[[email protected]] link C:\Users\30467\AppData\Roaming\npm\vue@ -> C:\Users\30467\AppData\Roaming\npm\node_modules\vue-cli\bin\vue
[[email protected]] link C:\Users\30467\AppData\Roaming\npm\vue-init@ -> C:\Users\30467\AppData\Roaming\npm\node_modules\vue-cli\bin\vue-init
[[email protected]] link C:\Users\30467\AppData\Roaming\npm\vue-list@ -> C:\Users\30467\AppData\Roaming\npm\node_modules\vue-cli\bin\vue-list
<!-- 安装成功，上面是最后一句代码 -->
----------步骤三：使用git打开指定目录，创建webpack模板的新项目----------
如果这里不适用Git工具，那么就必须在命令控制面板中找到指定目录下再执行以下命令
如果node.js 和 npm/cnpm 已经安装完毕，
需要创建新的项目，则直接执行后面的几个步骤即可。有时候会运行失败，不知道是什么情况。
此外，不能在已经创建好的项目中创建另外一个项目，否则直接报错。
-------------------------------------------------
<!-- 下面的：这里必须注意， ? Install vue-router? (Y/n) Y 一定要输入Y，即YES -->
#创建一个基于webpack模板的新项目
输入：vue init webpack my-project
显示如下：
韦德君@LAPTOP-AKTJNVLT MINGW64 /d/泉州时代/学习/vue.js
$ vue init webpack my-project
? Project name (my-project) <!-- 是否把项目命名为(my-project) 直接回车即可(默认肯定) -->
? Project name my-project
? Project description (A Vue.js project) <!-- 是否进行项目描述 直接回车即可(默认肯定) -->
? Project description A Vue.js project
? Author <!-- 是否填写作者 直接回车即可(默认肯定) -->
? Author
? Vue build standalone <!-- 是否独立创建Vue 直接回车即可(默认肯定) -->
? Install vue-router? (Y/n) Y <!-- 这里必须注意，一定要输入Y，即YES -->
? Install vue-router? Yes
? Use ESLint to lint your code? (Y/n) n
? Use ESLint to lint your code? No
? Set up unit tests (Y/n) n
? Set up unit tests No
? Setup e2e tests with Nightwatch? (Y/n) n
? Setup e2e tests with Nightwatch? No
? Should we run `npm install` for you after the project has been created? (recom
? Should we run `npm install` for you after the project has been created? (recom
mended) npm
vue-cli · Generated "my-project".
# Installing project dependencies ...
# ========================
npm WARN deprecated [email protected]: Deprecated. Please use https://github.com/webpack-contrib/mini-css-extract-plugin
npm WARN deprecated [email protected]: Browserslist 2 could fail on reading Browserslist >3.0 config used in other tools.
npm WARN deprecated [email protected]: Switch to the `bfj` package for fixes and new features!
<!-- 安装成功上面是最后一句代码 -->
<!-- 安装成功以下是警告，可能有可能没有： -->
npm WARN deprecated [email protected]: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.
npm WARN deprecated [email protected]: Browserslist 2 could fail on reading Browserslist >3.0 config used in other tools.
这样项目模板就算创建完毕了 ，ctrl + C 退出命令控制面板。
按完 Ctrl + C 就会跳转到如下：
韦德君@LAPTOP-AKTJNVLT MINGW64 /d/泉州时代/学习/vue.js
$
注意点： vue init webpack my-projectSecond 项目名称不能有大写字母，否则直接报错，如下：
? Project name (my-projectSecond) my-projectSecond
>> Sorry, name can no longer contain capital letters.
----------步骤四：输入下面的几句代码----------
#安装依赖包
1，输入：cd my-project + 回车 没有其他显示，只是换行继续输入下面一句代码。
2，输入：cnpm install + 回车 (淘宝镜像使用) / npm install (下载国外的npm才使用)
显示如下：
韦德君@LAPTOP-AKTJNVLT MINGW64 /d/泉州时代/学习/vue.js/my-project
$ cnpm install
platform unsupported [email protected] › [email protected] › [email protected] › [email protected] › fsevents@^1.2.7 Package require os(darwin) not compatible with your platform(win32)
[fsevents@^1.2.7] optional install error: Package require os(darwin) not compatible with your platform(win32)
√ Installed 37 packages
√ Linked 744 latest versions
[1/2] scripts.postinstall [email protected] › [email protected] › uglifyjs-webpack-plugin@^0.4.6 run "node lib/post_install.js", root: "D:\\泉州时代\\学习\\vue.js\\my-project\\node_modules\\[email protected]@uglifyjs-webpack-plugin"
[1/2] scripts.postinstall [email protected] › [email protected] › uglifyjs-webpack-plugin@^0.4.6 finished in 671ms
[2/2] scripts.postinstall [email protected] › [email protected] › core-js@^2.5.0 run "node postinstall || echo \"ignore\"", root: "D:\\泉州时代\\学习\\vue.js\\my-project\\node_modules\\[email protected]@core-js"
Thank you for using core-js ( https://github.com/zloirock/core-js ) for polyfilling JavaScript standard library!
The project needs your help! Please consider supporting of core-js on Open Collective or Patreon:
> https://opencollective.com/core-js
> https://www.patreon.com/zloirock
Also, the author of core-js ( https://github.com/zloirock ) is looking for a good job -)
[2/2] scripts.postinstall [email protected] › [email protected] › core-js@^2.5.0 finished in 751ms
√ Run 2 scripts
deprecate [email protected] › browserslist@^2.11.3 Browserslist 2 could fail on reading Browserslist >3.0 config used in other tools.
deprecate extract-text-webpack-plugin@^3.0.0 Deprecated. Please use https://github.com/webpack-contrib/mini-css-extract-plugin
deprecate [email protected] › [email protected] › [email protected] › browserslist@^1.7.6 Browserslist 2 could fail on reading Browserslist >3.0 config used in other tools.
deprecate [email protected] › [email protected] › [email protected] › [email protected] › fsevents@^1.2.7 One of your dependencies needs to upgrade to fsevents v2: 1) Proper nodejs v10+ support 2) No more fetching binaries from AWS, smaller package size
deprecate [email protected] › bfj-node4@^5.2.0 Switch to the `bfj` package for fixes and new features!
Recently updated (since 2019-11-05): 12 packages (detail see file
<!-- 安装成功表现一：一定会标注最近一次更新的时间是：(since 2019-11-05) -->
D:\泉州时代\学习\vue.js\my-project\node_modules\.recently_updates.txt)
√ All packages installed (920 packages installed from npm registry, used 1m(network 1m), speed 253.07kB/s, json 781(1.73MB), tarball 18.3MB)
<!-- 安装成功表现二：上面是最后一句代码，一定是: √ All... -->
韦德君@LAPTOP-AKTJNVLT MINGW64 /d/泉州时代/学习/vue.js/my-project
3，输入：npm run dev + 回车 (让项目跑起来，淘宝镜像和国外npm都可以使用，因为没有涉及下载)
显示如下：
韦德君@LAPTOP-AKTJNVLT MINGW64 /d/泉州时代/学习/vue.js/my-project
$ npm run dev (不管是淘宝镜像的 cnpm 还是直接使用 npm，启动都是用：npm run dev)
> [email protected] dev D:\泉州时代\学习\vue.js\my-project
> webpack-dev-server --inline --progress --config build/webpack.dev.conf.js
D:\Ȫ▒▒ʱ▒▒\ѧϰ\vue.js\my-project>"node" "D:\Ȫ▒▒ʱ▒▒\ѧϰ\vue.js\my-project\node_modules\.bin\\..\[email protected]@webpack-dev-server\bin\webpack-dev-server.js" --inline --progress --config build/webpack.dev.conf.js
10% building modules 0/1 modules 1 active ... webpack/hot/dev-server ./src/main 10% building modules 1/2 modules 1 active ...泉州时代\学习\vue.js\my-project\sr 10% building modules 2/3 modules 1 active ...client\index.js?http://localhost:8 10% building modules 3/4 modules 1 active ...\webpack\hot nonrecursive /^\.\/lo 10% building modules 3/5 modules 2 active ...5@webpack-dev-server\client\socket 10% building modules 3/6 modules 3 active ...@webpack-dev-server\client\overlay 10% building modules 3/7 modules 4 active [email protected]@webpack\hot\dev-server 10% building modules 4/7 modules 3 active [email protected]@webpack\hot\dev-server 10% building modules 4/8 modules 4 active ...vue.js\my-project\src\router\index 10% building modules 5/8 modules 3 active ...vue.js\my-project\src\router\index 10% building modules 6/8 modules 2 active ...vue.js\my-project\src\router\index 10% building modules 7/8 modules 1 active ...vue.js\my-project\src\router\index 10% building modules 7/9 modules 2 active [email protected]@webpack\hot\emitter 10% building modules 7/10 modules 3 active ...dules\[email protected]@vue\dist\vue.es 10% building modules 7/11 modules 4 active ...t\node_modules\[email protected]@url\ur 10% building modules 8/11 modules 3 active ...t\node_modules\[email protected]@url\ur 11% building modules 9/11 modules 2 active ...t\node_modules\[email protected]@url\ur 11% building modules 9/12 modules 3 active ...es\[email protected]@webpack\hot\lo 11% building modules 9/13 modules 4 active ....12.0@webpack\hot\log-apply-resul 11% building modules 10/13 modules 3 active ....12.0@webpack\hot\log-apply-resu 11% building modules 11/13 modules 2 active ...t\node_modules\[email protected]@url\u 11% building modules 11/14 modules 3 active ...泉州时代\学习\vue.js\my-project\ 11% building modules 11/15 modules 4 active ...project\src\components\HelloWorl 11% building modules 11/16 modules 5 active [email protected]@loglevel\lib\loglev 11% building modules 12/16 modules 4 active [email protected]@loglevel\lib\loglev 11% building modules 13/16 modules 3 active [email protected]@loglevel\lib\loglev 11% building modules 13/17 modules 4 active ...odules\[email protected]@events\even 11% building modules 14/17 modules 3 active ...odules\[email protected]@events\even 11% building modules 14/18 modules 4 active [email protected]@strip-ansi\ind 11% building modules 14/19 modules 5 active [email protected]@sockjs-client\dist\sock 11% building modules 15/19 modules 4 active [email protected]@sockjs-client\dist\sock 11% building modules 15/20 modules 5 active ...\node_modules\[email protected]@url\ut 11% building modules 15/21 modules 6 active ...s\[email protected]@ansi-html\ind 11% building modules 15/22 modules 7 active [email protected]@querystring-es3\ind 11% building modules 15/23 modules 8 active ...\[email protected]@punycode\punyco 11% building modules 15/24 modules 9 active ...泉州时代\学习\vue.js\my-project\ 11% building modules 15/25 modules 10 active ...project\src\components\HelloWor 11% building modules 16/25 modules 9 active ...project\src\components\HelloWorl 12% building modules 17/25 modules 8 active ...\[email protected]@punycode\punyco 12% building modules 17/26 modules 9 active ...ue-loader\lib\component-normaliz 12% building modules 18/26 modules 8 active ...ue-loader\lib\component-normaliz 12% building modules 18/27 modules 9 active ...泉州时代\学习\vue.js\my-project\ 12% building modules 18/28 modules 10 active ...project\src\components\HelloWorld.vue{ parser: "babylon" } is deprecated; we now treat it as { parser: "babel" }.
12% building modules 19/28 modules 9 active ...project\src\components\HelloWorl 12% building modules 20/28 modules 8 active ...ue-loader\lib\component-normaliz 12% building modules 21/28 modules 7 active ...ue-loader\lib\component-normaliz 12% building modules 22/28 modules 6 active ...ue-loader\lib\component-normaliz 12% building modules 22/29 modules 7 active [email protected]@html-entities\ind 12% building modules 23/29 modules 6 active [email protected]@html-entities\ind 12% building modules 24/29 modules 5 active [email protected]@html-entities\ind 13% building modules 25/29 modules 4 active [email protected]@html-entities\ind 13% building modules 25/30 modules 5 active ...1.3@vue-router\dist\vue-router.e 13% building modules 26/30 modules 4 active ...1.3@vue-router\dist\vue-router.e 13% building modules 27/30 modules 3 active ...1.3@vue-router\dist\vue-router.e 13% building modules 27/31 modules 4 active [email protected]@querystring-es3\deco 13% building modules 27/32 modules 5 active [email protected]@querystring-es3\enco 13% building modules 27/33 modules 6 active ...2.1@html-entities\lib\xml-entiti 13% building modules 27/34 modules 7 active ...1@html-entities\lib\html4-entiti 13% building modules 27/35 modules 8 active ...1@html-entities\lib\html5-entiti 13% building modules 27/36 modules 9 active [email protected]@webpack\buildin\modu 13% building modules 27/37 modules 10 active [email protected]@webpack\buildin\glo 13% building modules 28/37 modules 9 active [email protected]@webpack\buildin\glob 13% building modules 29/37 modules 8 active [email protected]@webpack\buildin\glob 13% building modules 30/37 modules 7 active [email protected]@webpack\buildin\glob 13% building modules 31/37 modules 6 active [email protected]@webpack\buildin\glob 13% building modules 32/37 modules 5 active ...1@html-entities\lib\html5-entiti 13% building modules 32/38 modules 6 active ....3.4@vue-hot-reload-api\dist\ind 13% building modules 32/39 modules 7 active ...泉州时代\学习\vue.js\my-project\ 13% building modules 33/39 modules 6 active ....3.4@vue-hot-reload-api\dist\ind 13% building modules 33/40 modules 7 active ...project\src\components\HelloWorl 14% building modules 34/40 modules 6 active ....3.4@vue-hot-reload-api\dist\ind 14% building modules 35/40 modules 5 active ....3.4@vue-hot-reload-api\dist\ind 14% building modules 35/41 modules 6 active ...泉州时代\学习\vue.js\my-project\ 14% building modules 35/42 modules 7 active ...project\src\components\HelloWorl 14% building modules 36/42 modules 6 active ...project\src\components\HelloWorl 14% building modules 37/42 modules 5 active ...project\src\components\HelloWorl 14% building modules 37/43 modules 6 active ...e-style-loader\lib\addStylesClie 14% building modules 38/43 modules 5 active ...e-style-loader\lib\addStylesClie 14% building modules 39/43 modules 4 active ...e-style-loader\lib\addStylesClie 14% building modules 39/44 modules 5 active ...vue.js\my-project\src\assets\log 14% building modules 40/44 modules 4 active ...vue.js\my-project\src\assets\log 14% building modules 40/45 modules 5 active [email protected]@ansi-regex\ind 14% building modules 41/45 modules 4 active [email protected]@ansi-regex\ind 15% building modules 42/45 modules 3 active [email protected]@ansi-regex\ind 15% building modules 42/46 modules 4 active ...@vue-style-loader\lib\listToStyl 15% building modules 43/46 modules 3 active ...@vue-style-loader\lib\listToStyl 15% building modules 44/46 modules 2 active ...@vue-style-loader\lib\listToStyl 15% building modules 45/46 modules 1 active ...@vue-style-loader\lib\listToStyl 15% building modules 46/47 modules 1 active [email protected]@css-loader\lib\css-ba 95% emitting DONE Compiled successfully in 14781ms4:18:45 PM
I Your application is running here: http://localhost:8080
韦德君@LAPTOP-AKTJNVLT MINGW64 /d/泉州时代/学习/vue.js/my-project
最后可以在网页地址栏输入：http://localhost:8080 进行访问。
注意，该命令控制面板是不能关闭的，否则就无法正常打开页面。
如果不小心关闭了，则使用Git在创建项目的文件夹中右击：Git Bash Here 进入该子程序。
然后再执行：npm run dev + 回车 等待运行完成。
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打开页面一定要有两个特点：
1，一定有路由 router（路由是需要配置的） 英 /'ruːtə(r)/路由器，路由
2，一定有一个页面（该页面是 .vue 格式的）