Problems with designing a custom view in Android studio

Question

I'm following a guide to creating a custom view in android studio whereby I define the view's attributes in XML but a few lines are causing errors in the classes. Here in the block of code causing troube:

<applicationprogramming.task401d.CustomView
   android:id="@+id/custView1"
   android:layout_width="0dp"
   android:layout_height="0dp"
   android:layout_margin="5dp"
   custom:circleColor="#6039ff"
   custom:circleLabel="Hello"
   custom:labelColor="#d9d908">
</applicationprogramming.task401d.CustomView>

The three lines of code bellow

custom:circleColor="#6039ff"
custom:circleLabel="Hello"
custom:labelColor="#d9d908

are causing the following error in one of the classes:

Error:(14) No resource identifier found for attribute 'circleColor' in package 'applicationprogramming.task401d'.

When I define these attributes: to get the text and colors specified using the names in attrs.xml

circleText = a.getString(R.styleable.CustomView_circleLabel);
circleCol = a.getInteger(R.styleable.CustomView_circleColor, 0);//0 is default
labelCol = a.getInteger(R.styleable.CustomView_labelColor, 0);

I get 'Cannot resolve Symbol 'R. And the only way to solve this issue is to remove where i define the attributes. Any help would be appreciated.

Thanks in advance

Answer 1

You need to apply custom schema to xml. Use it like below .

<applicationprogramming.task401d.CustomView
    xmlns:custom="http://schemas.android.com/apk/res-auto"
    android:id="@+id/custView1"
    android:layout_width="0dp"
    android:layout_height="0dp"
    android:layout_margin="5dp"
    custom:circleColor="#6039ff"
    custom:circleLabel="Hello"
    custom:labelColor="#d9d908"></applicationprogramming.task401d.CustomView>