正如另一张海报所提到的，Visual Studio将其生成为.gitignore的一部分(至少对于MVC 4):

# SQL Server files
App_Data/*.mdf
App_Data/*.ldf

因为你的项目可能是你的解决方案的一个子文件夹，而.gitignore文件存储在解决方案根目录中，这实际上不会触及本地数据库文件(Git在projectfolder/App_Data/*.mdf中看到它们)。为了解释这一点，我修改了这些行:

# SQL Server files
*App_Data/*.mdf
*App_Data/*.ldf

有一个在线工具可以让你根据你的操作系统、IDE、语言等生成。gitignore文件。看看http://www.gitignore.io/。

在2014年8月20日，这是为Visual Studio + Windows生成的文件。

# Created by http://www.gitignore.io

### VisualStudio ###
## Ignore Visual Studio temporary files, build results, and
## files generated by popular Visual Studio add-ons.

# User-specific files
*.suo
*.user
*.sln.docstates

# Build results
[Dd]ebug/
[Dd]ebugPublic/
[Rr]elease/
[Rr]eleases/
x64/
x86/
build/
bld/
[Bb]in/
[Oo]bj/

# Roslyn cache directories
*.ide/

# MSTest test Results
[Tt]est[Rr]esult*/
[Bb]uild[Ll]og.*

#NUNIT
*.VisualState.xml
TestResult.xml

# Build Results of an ATL Project
[Dd]ebugPS/
[Rr]eleasePS/
dlldata.c

*_i.c
*_p.c
*_i.h
*.ilk
*.meta
*.obj
*.pch
*.pdb
*.pgc
*.pgd
*.rsp
*.sbr
*.tlb
*.tli
*.tlh
*.tmp
*.tmp_proj
*.log
*.vspscc
*.vssscc
.builds
*.pidb
*.svclog
*.scc

# Chutzpah Test files
_Chutzpah*

# Visual C++ cache files
ipch/
*.aps
*.ncb
*.opensdf
*.sdf
*.cachefile

# Visual Studio profiler
*.psess
*.vsp
*.vspx

# TFS 2012 Local Workspace
$tf/

# Guidance Automation Toolkit
*.gpState

# ReSharper is a .NET coding add-in
_ReSharper*/
*.[Rr]e[Ss]harper
*.DotSettings.user

# JustCode is a .NET coding addin-in
.JustCode

# TeamCity is a build add-in
_TeamCity*

# DotCover is a Code Coverage Tool
*.dotCover

# NCrunch
_NCrunch_*
.*crunch*.local.xml

# MightyMoose
*.mm.*
AutoTest.Net/

# Web workbench (sass)
.sass-cache/

# Installshield output folder
[Ee]xpress/

# DocProject is a documentation generator add-in
DocProject/buildhelp/
DocProject/Help/*.HxT
DocProject/Help/*.HxC
DocProject/Help/*.hhc
DocProject/Help/*.hhk
DocProject/Help/*.hhp
DocProject/Help/Html2
DocProject/Help/html

# Click-Once directory
publish/

# Publish Web Output
*.[Pp]ublish.xml
*.azurePubxml
# TODO: Comment the next line if you want to checkin your web deploy settings 
# but database connection strings (with potential passwords) will be unencrypted
*.pubxml
*.publishproj

# NuGet Packages
*.nupkg
# The packages folder can be ignored because of Package Restore
**/packages/*
# except build/, which is used as an MSBuild target.
!**/packages/build/
# If using the old MSBuild-Integrated Package Restore, uncomment this:
#!**/packages/repositories.config

# Windows Azure Build Output
csx/
*.build.csdef

# Windows Store app package directory
AppPackages/

# Others
sql/
*.Cache
ClientBin/
[Ss]tyle[Cc]op.*
~$*
*~
*.dbmdl
*.dbproj.schemaview
*.pfx
*.publishsettings
node_modules/

# RIA/Silverlight projects
Generated_Code/

# Backup & report files from converting an old project file
# to a newer Visual Studio version. Backup files are not needed,
# because we have git ;-)
_UpgradeReport_Files/
Backup*/
UpgradeLog*.XML
UpgradeLog*.htm

# SQL Server files
*.mdf
*.ldf

# Business Intelligence projects
*.rdl.data
*.bim.layout
*.bim_*.settings

# Microsoft Fakes
FakesAssemblies/


### Windows ###
# Windows image file caches
Thumbs.db
ehthumbs.db

# Folder config file
Desktop.ini

# Recycle Bin used on file shares
$RECYCLE.BIN/

# Windows Installer files
*.cab
*.msi
*.msm
*.msp

参见官方GitHub的“有用的。gitignore模板集合”。

Visual Studio的.gitignore可以在这里找到: https://github.com/github/gitignore/blob/main/VisualStudio.gitignore

我在c#项目中使用下面的.gitignore。在需要时添加其他模式。

[Oo]bj
[Bb]in
*.user
*.suo
*.[Cc]ache
*.bak
*.ncb
*.log 
*.DS_Store
[Tt]humbs.db 
_ReSharper.*
*.resharper
Ankh.NoLoad

使用Visual Studio添加.gitignore

打开Visual Studio和需要忽略文件的解决方案。从顶部菜单选择Git > Settings。

上面将打开Visual Studio的选项，选择源代码控制> Git全局设置。从左侧列表中选择Git Repository Settings，然后单击“忽略文件”的“添加”按钮。

上面的代码将添加(并提交)一个.gitignore文件，其中包含典型Visual Studio设置中忽略的所有适当文件。

https://elanderson.net/2020/10/add-git-ignore-to-an-existing-visual-studio-solution-new-git-experience/

注意，如果你的repo根目录中已经有一个.gitignore文件，“添加”按钮将显示“编辑”，按下该按钮将只是打开文件而不更新它，这不是很有帮助。在这种情况下，您可以首先重命名您的.gitignore文件，单击Add按钮，取消新的.gitignore文件，然后按照您喜欢的方式合并保存的副本更改。

我明白这是一个老问题，还在分享一个信息。在Visual Studio 2017中，只需右键单击解决方案文件，并选择将解决方案添加到源代码控制

这将向源文件夹中添加两个文件。

.gitattributes .gitignore

这是最简单的方法。