iOS开发必备：cocoapods

一、什么是cocoapods？

CocoaPods是一个用来帮助我们管理第三方依赖库的工具。

它可以解决库与库之间的依赖关系，下载库的源代码，同时通过创建一个Xcode的workspace来将这些第三方库和我们的工程连接起来，供我们开发使用。

使用CocoaPods的目的是让我们能自动化的、集中的、直观的管理第三方开源库（比如JSONKit，AFNetWorking等）。

二、如何安装？

方法一：当然是官方的文档最权威啦，这就需要去官网看看了。

https://cocoapods.org/

CocoaPods是Swift和Objective-C Cocoa项目的依赖管理器。 它有超过28万个图书馆，并在超过170万的应用程序中使用。 CocoaPods可以帮助您优化扩展项目。

CocoaPods是用Ruby构建的，可以使用OS X上提供的默认Ruby安装。我们建议您使用默认的ruby。

使用默认的Ruby安装可能需要在安装gem时使用sudo。 更多安装说明在指南中。

https://guides.cocoapods.org/using/getting-started.html#getting-started

这是官方的安装指南。

如果你英语和我一样不太好的话，还是用民间的传统方法吧。

方法二：小白新手安装步骤详解！！！

CocoaPods是以Ruby gem包的形式被安装的。Mac OS系统是自带Ruby环境的。

可以先在终端（Terminal）输入：sudo gem install cocoapods，如果不出错的话，那是万幸了，但是基本上都是会出现error的，因为ruby的软件源rubygems.org因为使用亚马逊的云服务，被我天朝屏蔽了，所以需要更新一下ruby的源。

保守起见首先还是先查看下当前ruby版本：

打开终端（Terminal）输入 

ruby -v

2.更新Ruby源，网上的一种解决方案是将远替换成淘宝的，不过现在淘宝的 ruby 源已经不维护了，请替换成 Ruby China，

具体输入：

gem sources --removehttps://rubygems.org/     /*去掉ruby源*/

gem sources -ahttps://gems.ruby-china.org/       /*添加新的源*/

gem sources -l      /*查看当前ruby源*/

3.安装：

具体输入：

sudo gem install cocoapods

4.如果你的gem太老，可能也会有问题，可以尝试用如下命令升级gem:

具体输入：

sudo gem update --system

之后的新建podfile网上都有流程啦，自己动手一下，搜索。

我要说一下我遇到的问题。

cocoapods安装及使用遇到的问题合集：

1.

安装cocoapods过程中，需要输入电脑密码，输入密码的时候，你会发现光标和平常不一样，而且你输入的时候数字会显示不出来，不用理会，直接输入完按enter/return回车键。

2.当输入“sudo gem install cocoapods”或者“sudo gem install -n /usr/local/bin cocoapods”

出现以下错误：

ERROR:  While executing gem ... (Gem::DependencyError)

Unable to resolve dependencies: cocoapods requires cocoapods-core (= 1.2.0), cocoapods-downloader (< 2.0, >= 1.1.3), cocoapods-trunk (< 2.0, >= 1.1.2), molinillo (~> 0.5.5), xcodeproj (< 2.0, >= 1.4.1)

yangyangyangdeMacBook-Pro:~ yang$ sudo nvram boot-args="rootless=0"

nvram: Error setting variable - 'boot-args': (iokit/common) general error

解决方法：

输入：

rvm list known

出现错误：-bash: rvm: command not found

则继续输入：

curl -L get.rvm.io | bash -s stable

出现以下：

即表示rvm安装完成。

继续输入：

rvm list known

出现以下：

会显示出所有的ruby的版本

yangyangyangdeMacBook-Pro:~ yang$ rvm list known

# MRI Rubies

[ruby-]1.8.6[-p420]

[ruby-]1.8.7[-head] # security released on head

[ruby-]1.9.1[-p431]

[ruby-]1.9.2[-p330]

[ruby-]1.9.3[-p551]

[ruby-]2.0.0[-p648]

[ruby-]2.1[.10]

[ruby-]2.2[.6]

[ruby-]2.3[.3]

[ruby-]2.4[.0]

ruby-head

.

.

.

# IronRuby

ironruby[-1.1.3]

ironruby-head

继续输入：sudo gem install cocoa pods

出现以下：

yangyangyangdeMacBook-Pro:~ yang$ sudo gem install cocoa pods

Password:

Fetching: i18n-0.7.0.gem (100%)

Successfully installed i18n-0.7.0

Fetching: thread_safe-0.3.5.gem (100%)

Successfully installed thread_safe-0.3.5

Fetching: tzinfo-1.2.2.gem (100%)

Successfully installed tzinfo-1.2.2

Fetching: minitest-5.9.1.gem (100%)

Successfully installed minitest-5.9.1

Fetching: concurrent-ruby-1.0.2.gem (100%)

Successfully installed concurrent-ruby-1.0.2

Fetching: activesupport-5.0.1.gem (100%)

ERROR:  Error installing cocoa:

activesupport requires Ruby version >= 2.2.2.

ERROR:  Error installing pods:

activesupport requires Ruby version >= 2.2.2.

继续输入：rvm install 2.2.2  /*选择安装最新的Ruby*/

出现以下：

Searching for binary rubies, this might take some time.

Found remote file https://rvm_io.global.ssl.fastly.net/binaries/osx/10.12/x86_64/ruby-2.2.2.tar.bz2

Checking requirements for osx.

About to install Homebrew, press `Enter` for default installation in `/usr/local`,

type new path if you wish custom Homebrew installation (the path needs to be writable for user)

:

==> This script will install:

/usr/local/bin/brew

/usr/local/share/doc/homebrew

/usr/local/share/man/man1/brew.1

/usr/local/share/zsh/site-functions/_brew

/usr/local/etc/bash_completion.d/brew

/usr/local/Homebrew

Press RETURN to continue or any other key to abort

==> Downloading and installing Homebrew...

remote: Counting objects: 5079, done.

remote: Compressing objects: 100% (3186/3186), done.

remote: Total 5079 (delta 2798), reused 3338 (delta 1722), pack-reused 0

Receiving objects: 100% (5079/5079), 2.66 MiB | 44.00 KiB/s, done.

Resolving deltas: 100% (2798/2798), done.

From https://github.com/Homebrew/brew

...

* [new tag]        1.1.9      -> 1.1.9

HEAD is now at dfad3f3 Merge pull request #2034 from reitermarkus/spec-gpg

==> Tapping homebrew/core

Cloning into '/usr/local/Homebrew/Library/Taps/homebrew/homebrew-core'...

remote: Counting objects: 4137, done.

remote: Compressing objects: 100% (4013/4013), done.

remote: Total 4137 (delta 30), reused 433 (delta 9), pack-reused 0

Receiving objects: 100% (4137/4137), 3.31 MiB | 87.00 KiB/s, done.

Resolving deltas: 100% (30/30), done.

Tapped 4010 formulae (4,166 files, 10.4M)

==> Cleaning up /Library/Caches/Homebrew...

==> Migrating /Library/Caches/Homebrew to /Users/yang/Library/Caches/Homebrew...

==> Deleting /Library/Caches/Homebrew...

Already up-to-date.

==> Installation successful!

==> Homebrew has enabled anonymous aggregate user behaviour analytics.

Read the analytics documentation (and how to opt-out) here:

https://git.io/brew-analytics

==> Next steps:

- Run `brew help` to get started

- Further documentation:

https://git.io/brew-docs

Installing requirements for osx.

Updating system.........

Installing required packages: autoconf, automake, libtool, pkg-config, coreutils, libyaml, readline, libksba, openssl...........

Certificates in '/usr/local/etc/openssl/cert.pem' are already up to date.

Requirements installation successful.

ruby-2.2.2 - #configure

ruby-2.2.2 - #download

% Total    % Received % Xferd  Average Speed  Time    Time    Time  Current

Dload  Upload  Total  Spent    Left  Speed

100 6854k  100 6854k    0    0  14400      0  0:08:07  0:08:07 --:--:-- 17131

No checksum for downloaded archive, recording checksum in user configuration.

ruby-2.2.2 - #validate archive

ruby-2.2.2 - #extract

ruby-2.2.2 - #validate binary

ruby-2.2.2 - #setup

ruby-2.2.2 - #gemset created /Users/yang/.rvm/gems/ruby-2.2.2@global

ruby-2.2.2 - #importing gemset /Users/yang/.rvm/gemsets/global.gems.............

ruby-2.2.2 - #generating global wrappers........

ruby-2.2.2 - #gemset created /Users/yang/.rvm/gems/ruby-2.2.2

ruby-2.2.2 - #importing gemsetfile /Users/yang/.rvm/gemsets/default.gems evaluated to empty gem list

ruby-2.2.2 - #generating default wrappers........

Updating certificates in '/etc/openssl/cert.pem'.

mkdir: /etc/openssl: Permission denied

mkdir -p "/etc/openssl" failed, retrying with sudo

yang password required for 'mkdir -p /etc/openssl':

and sudo mkdir worked

继续输入：

sudo gem install cocoapods

出现以下：

最终看到了：26 gems installed

就代表最终cocoapods安装好啦

三、如何新建Podfile文件？

终端输入：

vim Podfile

点击“i”，进入文件编辑模式

输入：

platform :ios, '10.0'  /*设置iOS 10的版本号*/

target 'Cloud Weather' do  /*目标文件*/

pod 'AFNetworking'    /*输入你要用到的第三方库，后面可以设置版本号，如果不设置就是默认最新版本*/

end

编辑完成后，然后按Esc，并且输入“ ：”号进入vim命令模式，然后在冒号后边输入wq

注意：键盘输入 ：后，才能输入wq。回车后发现PodTest项目总目录中多一个Podfile文件

继续在终端中输入：

pod install

如上图所示，

打开文件夹，会出现以下三个文件