Can't find android.support.design.widget.Snackbar in support design library

Solution 1:

You must add the design dependency in your gradle file (module app) according to

AndroidX build artifact

implementation "com.google.android.material:material:1.1.0-alpha06"

Old build artifact

implementation "com.android.support:design:28.0.0"

If you are using Support libraries, you can visit Support Library Packages  |  Android Developers, for the latest Design Support Library version. If you're new to AndroidX and want to use it, you can find more information about migrating to the new dependencies here.

Source: http://android-developers.blogspot.co.il/2015/05/android-design-support-library.html
(Scroll all the way down)

Solution 2:

I solved the problem now :)

1. Open [File] -> [Project Structure...]

2. Select [app] in the left pad

3. Select [Dependencies] in the right tabs

4. Click [+] button on the right side

5. Select [1 Library dependency]

6. Choose [com.android.support:design ~~]

7. Click [OK] button and so on

Result: library added in [Project's External Libraries]

------ edit -----------------------------------

You can also add this External library in build.gradle(Module:app)

press Alt+Enter in build.gradle(Module:app)

-> add library dependency

-> choose what you need

and press "Sync Now" positioned up right corner