I'm new in android and i have this error, i've been trying looking everywhere for the solution and still don't know how to solve this. I have this :
Error:Execution failed for task ':app:mergeDebugResources'.> -1
and the effect is every R in my activities got "cannot resolve symbol R"
i've been trying to clean, build and sync with gradle but still not working..
this is my resources: strings.xml
<resources>
<string name="app_name">mLibrary AeU</string>
<string name="action_search">action_search</string>
<string name="search_hint">search_hint</string>
<string name="welcome">welcome</string>
<string name="btn_logout">btn_logout</string>
</resources>
colors.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="colorPrimary">#2f2d79</color>
<color name="colorPrimaryDark">#303F9F</color>
<color name="colorAccent">#FF4081</color>
<color name="callNumber">#666666</color>
<color name="author_and_year">#888888</color>
<color name="list_divider">#d9d9d9</color>
<color name="list_row_start_color">#ffffff</color>
<color name="list_row_end_color">#ffffff</color>
<color name="list_row_hover_start_color">#ebeef0</color>
<color name="list_row_hover_end_color">#ebeef0</color>
</resources>
dimens.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<!-- Default screen margins, per the Android Design guidelines. -->
<dimen name="activity_horizontal_margin">16dp</dimen>
<dimen name="activity_vertical_margin">16dp</dimen>
<dimen name="title">17dp</dimen>
<dimen name="author">15dip</dimen>
<dimen name="callNumber">13dip</dimen>
<dimen name="year">13dip</dimen>
</resources>
styles.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
</style>
</resources>
I need your help.