添加.gitignore以及过滤文件生效

最近公司项目代码转移到Gitlab，转移后发现过滤文件失效，这次就记录一下添加以及生效方法。

添加.gitignore

github可以下载各种语音对应的.gitignore文件，访问地址：https://github.com/github/gitignore

完善.gitignore

下载后我对文件进行了修改，我直接贴出来

# Xcode
#
# gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore
.DS_Store

## User settings
xcuserdata/

## compatibility with Xcode 8 and earlier (ignoring not required starting Xcode 9)
*.xcscmblueprint
*.xccheckout
*.xcuserstate

## compatibility with Xcode 3 and earlier (ignoring not required starting Xcode 4)
build/
DerivedData/
*.moved-aside
*.pbxuser
!default.pbxuser
*.mode1v3
!default.mode1v3
*.mode2v3
!default.mode2v3
*.perspectivev3
!default.perspectivev3

## Obj-C/Swift specific
*.hmap

## App packaging
*.ipa
*.dSYM.zip
*.dSYM

# CocoaPods
#
# We recommend against adding the Pods directory to your .gitignore. However
# you should judge for yourself, the pros and cons are mentioned at:
# https://guides.cocoapods.org/using/using-cocoapods.html#should-i-check-the-pods-directory-into-source-control

Pods/

# Add this line if you want to avoid checking in source code from the Xcode workspace
# *.xcworkspace

# Carthage
#
# Add this line if you want to avoid checking in source code from Carthage dependencies.
# Carthage/Checkouts

Carthage/Build/

# fastlane
#
# It is recommended to not store the screenshots in the git repo.
# Instead, use fastlane to re-generate the screenshots whenever they are needed.
# For more information about the recommended setup visit:
# https://docs.fastlane.tools/best-practices/source-control/#source-control

fastlane/report.xml
fastlane/Preview.html
fastlane/screenshots/**/*.png
fastlane/test_output

# Code Injection
#
# After new code Injection tools there's a generated folder /iOSInjectionProject
# https://github.com/johnno1962/injectionforxcode

iOSInjectionProject/

.gitignore文件提交到仓库

Mac显示隐藏文件的快捷键：command+shift+.

终端显示当前隐藏文件命令：

cd 文件名
ls -a

 查看.gitignore没问题（本人没看，谁知道我在修改文件名时变成了.gitignore.gitignore这样的格式）这进行提交

git add .gitignore   
git commit -m "添加项目忽略文件" 
git push 

.gitignore生效

大家应该知道git规则，.gitignore只能忽略那些原来没有被track的文件，如果某些文件已经被纳入了版本管理中，则修改.gitignore是无效的

解决办法：我们可以先删除缓存路径，使用add .添加重新提交

git rm -r --cached .    
git add .   
git commit -m "update .gitignore"
git push