git作为代码管理工具，.gitignore文件用来忽略哪些哪些文件不用添加到仓库管理
https://www.gitignore.io/ 这个网址输入变成语言会帮你生成常用的忽略文件
如：IOS项目，输入Xcode、Object-C、Swift、C、C++、git、svn生成：
# Created by https://www.gitignore.io/api/objective-c,swift,c,c++,xcode,git,svn
### Objective-C ###
# Xcode
#
# gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore
## Build generated
build/
DerivedData/
## Various settings
*.pbxuser
!default.pbxuser
*.mode1v3
!default.mode1v3
*.mode2v3
!default.mode2v3
*.perspectivev3
!default.perspectivev3
xcuserdata/
## Other
*.moved-aside
*.xcuserstate
## Obj-C/Swift specific
*.hmap
*.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/
# 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://github.com/fastlane/fastlane/blob/master/fastlane/docs/Gitignore.md
fastlane/report.xml
fastlane/Preview.html
fastlane/screenshots
fastlane/test_output
# Code Injection
#
# After new code Injection tools there's a generated folder /iOSInjectionProject
# https://github.com/johnno1962/injectionforxcode
iOSInjectionProject/
### Objective-C Patch ###
*.xcscmblueprint
### Swift ###
# Xcode
#
# gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore
## Build generated
## Various settings
## Other
## Obj-C/Swift specific
## Playgrounds
timeline.xctimeline
playground.xcworkspace
# Swift Package Manager
#
# Add this line if you want to avoid checking in source code from Swift Package Manager dependencies.
# Packages/
.build/
# 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/
# Carthage
#
# Add this line if you want to avoid checking in source code from Carthage dependencies.
# Carthage/Checkouts
# 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://github.com/fastlane/fastlane/blob/master/fastlane/docs/Gitignore.md
### C ###
# Prerequisites
*.d
# Object files
*.o
*.ko
*.obj
*.elf
# Linker output
*.ilk
*.map
*.exp
# Precompiled Headers
*.gch
*.pch
# Libraries
*.lib
*.a
*.la
*.lo
# Shared objects (inc. Windows DLLs)
*.dll
*.so
*.so.*
*.dylib
# Executables
*.exe
*.out
*.app
*.i*86
*.x86_64
*.hex
# Debug files
*.dSYM/
*.su
*.idb
*.pdb
# Kernel Module Compile Results
*.mod*
*.cmd
modules.order
Module.symvers
Mkfile.old
dkms.conf
### C++ ###
# Prerequisites
# Compiled Object files
*.slo
# Precompiled Headers
# Compiled Dynamic libraries
# Fortran module files
*.mod
*.smod
# Compiled Static libraries
*.lai
# Executables
### Xcode ###
# Xcode
#
# gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore
## Build generated
## Various settings
## Other
*.xccheckout
### Git ###
*.orig
### SVN ###
.svn/
###macOS###
*.DS_Store
.AppleDouble
.LSOverride
# Icon must end with two
# Icon
# Thumbnails
._*
# Files that might appear in the root of a volume
.DocumentRevisions-V100
.fseventsd
.Spotlight-V100
.TemporaryItems
.Trashes
.VolumeIcon.icns
.com.apple.timemachine.donotpresent
# Directories potentially created on remote AFP share
.AppleDB
.AppleDesktop
#Network Trash Folder
#Temporary Items
.apdisk
Android项目，输入Eclipse、Java、C、C++、Android、Intellij、Intellij+iml、git、svn生成：
# Created by https://www.gitignore.io/api/java,c,c++,android,eclipse,intellij,intellij+iml
### C ###
# Prerequisites
*.d
# Object files
*.o
*.ko
*.obj
*.elf
# Linker output
*.ilk
*.map
*.exp
# Precompiled Headers
*.gch
*.pch
# Libraries
*.lib
*.a
*.la
*.lo
# Shared objects (inc. Windows DLLs)
*.dll
*.so
*.so.*
*.dylib
# Executables
*.exe
*.out
*.app
*.i*86
*.x86_64
*.hex
# Debug files
*.dSYM/
*.su
*.idb
*.pdb
# Kernel Module Compile Results
*.mod*
*.cmd
modules.order
Module.symvers
Mkfile.old
dkms.conf
### C++ ###
# Prerequisites
# Compiled Object files
*.slo
# Precompiled Headers
# Compiled Dynamic libraries
# Fortran module files
*.mod
*.smod
# Compiled Static libraries
*.lai
# Executables
### Android ###
# Built application files
*.apk
*.ap_
# Files for the ART/Dalvik VM
*.dex
# Java class files
*.class
# Generated files
bin/
gen/
out/
# Gradle files
.gradle/
build/
# Local configuration file (sdk path, etc)
local.properties
# Proguard folder generated by Eclipse
proguard/
# Log Files
*.log
# Android Studio Navigation editor temp files
.navigation/
# Android Studio captures folder
captures/
# Intellij
*.iml
.idea/workspace.xml
.idea/tasks.xml
.idea/libraries
# Keystore files
*.jks
# External native build folder generated in Android Studio 2.2 and later
.externalNativeBuild
### Android Patch ###
gen-external-apklibs
### Eclipse ###
.metadata
tmp/
*.tmp
*.bak
*.swp
*~.nib
.settings/
.loadpath
.recommenders
# Eclipse Core
.project
# External tool builders
.externalToolBuilders/
# Locally stored "Eclipse launch configurations"
*.launch
# PyDev specific (Python IDE for Eclipse)
*.pydevproject
# CDT-specific (C/C++ Development Tooling)
.cproject
# JDT-specific (Eclipse Java Development Tools)
.classpath
# Java annotation processor (APT)
.factorypath
# PDT-specific (PHP Development Tools)
.buildpath
# sbteclipse plugin
.target
# Tern plugin
.tern-project
# TeXlipse plugin
.texlipse
# STS (Spring Tool Suite)
.springBeans
# Code Recommenders
.recommenders/
### Intellij ###
# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and Webstorm
# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
# User-specific stuff:
# Sensitive or high-churn files:
.idea/dataSources/
.idea/dataSources.ids
.idea/dataSources.xml
.idea/dataSources.local.xml
.idea/sqlDataSources.xml
.idea/dynamic.xml
.idea/uiDesigner.xml
# Gradle:
.idea/gradle.xml
# Mongo Explorer plugin:
.idea/mongoSettings.xml
## File-based project format:
*.iws
## Plugin-specific files:
# IntelliJ
/out/
# mpeltonen/sbt-idea plugin
.idea_modules/
# JIRA plugin
atlassian-ide-plugin.xml
# Crashlytics plugin (for Android Studio and IntelliJ)
com_crashlytics_export_strings.xml
crashlytics.properties
crashlytics-build.properties
fabric.properties
### Intellij Patch ###
# Comment Reason: https://github.com/joeblau/gitignore.io/issues/186#issuecomment-215987721
# *.iml
# modules.xml
# .idea/misc.xml
# *.ipr
### Intellij+iml ###
# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and Webstorm
# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
# User-specific stuff:
# Sensitive or high-churn files:
# Gradle:
# Mongo Explorer plugin:
## File-based project format:
## Plugin-specific files:
# IntelliJ
# mpeltonen/sbt-idea plugin
# JIRA plugin
# Crashlytics plugin (for Android Studio and IntelliJ)
### Intellij+iml Patch ###
# Reason: https://github.com/joeblau/gitignore.io/issues/186#issuecomment-249601023
modules.xml
.idea/misc.xml
*.ipr
### Java ###
# BlueJ files
*.ctxt
# Mobile Tools for Java (J2ME)
.mtj.tmp/
# Package Files #
*.jar
*.war
*.ear
# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
hs_err_pid*
### Git ###
*.orig
### SVN ###
.svn/
###macOS###
*.DS_Store
.AppleDouble
.LSOverride
# Icon must end with two
# Icon
# Thumbnails
._*
# Files that might appear in the root of a volume
.DocumentRevisions-V100
.fseventsd
.Spotlight-V100
.TemporaryItems
.Trashes
.VolumeIcon.icns
.com.apple.timemachine.donotpresent
# Directories potentially created on remote AFP share
.AppleDB
.AppleDesktop
#Network Trash Folder
#Temporary Items
.apdisk
J2EE项目，输入Eclipse、Java、Intellij、Intellij+iml、git、svn生成：
# Created by https://www.gitignore.io/api/eclipse,intellij,intellij+iml,java
### Eclipse ###
.metadata
bin/
tmp/
*.tmp
*.bak
*.swp
*~.nib
local.properties
.settings/
.loadpath
.recommenders
# Eclipse Core
.project
# External tool builders
.externalToolBuilders/
# Locally stored "Eclipse launch configurations"
*.launch
# PyDev specific (Python IDE for Eclipse)
*.pydevproject
# CDT-specific (C/C++ Development Tooling)
.cproject
# JDT-specific (Eclipse Java Development Tools)
.classpath
# Java annotation processor (APT)
.factorypath
# PDT-specific (PHP Development Tools)
.buildpath
# sbteclipse plugin
.target
# Tern plugin
.tern-project
# TeXlipse plugin
.texlipse
# STS (Spring Tool Suite)
.springBeans
# Code Recommenders
.recommenders/
### Intellij ###
# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and Webstorm
# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
# User-specific stuff:
.idea/workspace.xml
.idea/tasks.xml
# Sensitive or high-churn files:
.idea/dataSources/
.idea/dataSources.ids
.idea/dataSources.xml
.idea/dataSources.local.xml
.idea/sqlDataSources.xml
.idea/dynamic.xml
.idea/uiDesigner.xml
# Gradle:
.idea/gradle.xml
.idea/libraries
# Mongo Explorer plugin:
.idea/mongoSettings.xml
## File-based project format:
*.iws
## Plugin-specific files:
# IntelliJ
/out/
# mpeltonen/sbt-idea plugin
.idea_modules/
# JIRA plugin
atlassian-ide-plugin.xml
# Crashlytics plugin (for Android Studio and IntelliJ)
com_crashlytics_export_strings.xml
crashlytics.properties
crashlytics-build.properties
fabric.properties
### Intellij Patch ###
# Comment Reason: https://github.com/joeblau/gitignore.io/issues/186#issuecomment-215987721
# *.iml
# modules.xml
# .idea/misc.xml
# *.ipr
### Intellij+iml ###
# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and Webstorm
# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
# User-specific stuff:
# Sensitive or high-churn files:
# Gradle:
# Mongo Explorer plugin:
## File-based project format:
## Plugin-specific files:
# IntelliJ
# mpeltonen/sbt-idea plugin
# JIRA plugin
# Crashlytics plugin (for Android Studio and IntelliJ)
### Intellij+iml Patch ###
# Reason: https://github.com/joeblau/gitignore.io/issues/186#issuecomment-249601023
*.iml
modules.xml
.idea/misc.xml
*.ipr
### Java ###
*.class
# BlueJ files
*.ctxt
# Mobile Tools for Java (J2ME)
.mtj.tmp/
# Package Files #
*.jar
*.war
*.ear
# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
hs_err_pid*
### Git ###
*.orig
### SVN ###
.svn/
###macOS###
*.DS_Store
.AppleDouble
.LSOverride
# Icon must end with two
# Icon
# Thumbnails
._*
# Files that might appear in the root of a volume
.DocumentRevisions-V100
.fseventsd
.Spotlight-V100
.TemporaryItems
.Trashes
.VolumeIcon.icns
.com.apple.timemachine.donotpresent
# Directories potentially created on remote AFP share
.AppleDB
.AppleDesktop
#Network Trash Folder
#Temporary Items
.apdisk