java.lang.UnsupportedOperationException: Can't convert to color: type=0x2 at API Launch21

[Rossere]

java.lang.UnsupportedOperationException: Can't convert to color: type=0x2

There's a mistake in testing API passenger21 (i.e., everything falls down, even though 5+ of the Android version works). Plus AndroidStudio releases warnings in files xml-drawablebut doesn't give any clues. What's the problem?My fault. What do we do?

Here. xml drawable:

<shape 
   xmlns:android="http://schemas.android.com/apk/res/android">
<gradient

android:angle="90"

android:endColor="?colorPrimary"

android:startColor="@android:color/transparent"/>
</shape>

[nishika]

According to the https://stackoverflow.com/a/13471695/3212712 The problem is before API 21 No colour attachments can be used xml-drawablereferences to colours @color♪ We're gonna have to convert the folded file so:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<gradient

android:angle="90"

android:endColor="@color/my_awesome_color_that_i_use_as_color_primary_in_my_awesome_theme"

android:startColor="@android:color/transparent"/>
</shape>

If you and I need to use the same thing. xml-drawable But with different colors for different topics, nothing remains but:

1. Create an attribut-sniff. xml-drawable

   <?xml version="1.0" encoding="utf-8"?>
   
   <resources>
   
   <!-- по ссылке утверждают, что надо обязательно только lowerCase пользовать в названии -->
   
   <attr name="my_drawable" format="reference" />
   
   </resources>
   
   

2. To designate a reference to a separate xml-drawable in this attribution to every subject

   <style name="MyTheme" parent="@android:style/Theme.NoTitleBar">
   
   <item name="my_drawable">@drawable/my_drawable_for_this_theme</item>
   
   </style>
   
   

3. Use this attribut where you need to. TextView

   <TextView android:background="?my_drawable" />
   
   

4. Of course not to forget to create one. xml-drawable with specific colour for each topic