Step 1: Add following content to the file .gitignore.
# User-specific files
*.suo
*.user
*.userosscache
*.sln.docstates
# Build results
[Dd]ebug/
[Dd]ebugPublic/
[Rr]elease/
[Rr]eleases/
x64/
x86/
bld/
[Bb]in/
[Oo]bj/
# Visual Studio 2015 cache/options directory
.vs/
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Step 2: Make sure take effect
If the issue still exists, that's because settings in .gitignore can only ignore files that were originally not tracked. If some files have already been included in the version control system, then modifying .gitignore is invalid. To solve this issue completely, you need to open Git Bash or Package Manager Console (see screenshot below) to run following commands in the repository root folder.
git rm -r --cached .
git add .
git commit -m "Update .gitignore"
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