title: Kotlin Android - Unable to get @BindingAdapter to work
body: <p>I keep getting the binding error when trying to use the @BindingAdapter. Try for 3 days and follow numerous online articles on this subject, but still getting the below error.</p>
  
  <pre><code>@BindingAdapter("focusableColor")
  fun setFocusableColor(v:CardView,  color:Int) {
      println("hello")
  }
  
  class MainActivity : AppCompatActivity() {
      override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)
            val binding:ActivityMainBinding  = 
                DataBindingUtil.setContentView(this,R.layout.activity_main)
            etc...
      }
  
  
  
  In current_task_layout.xml
  
  &lt;layout xmlns:app="http://schemas.android.com/apk/res-auto"
      xmlns:tools="http://schemas.android.com/tools"
      xmlns:android="http://schemas.android.com/apk/res/android"&gt;
      &lt;data&gt;
              &lt;variable name="task" type="com.edenhan.simplytask.Task"&gt;
              &lt;/variable&gt;
      &lt;/data&gt;
  
  &lt;android.support.v7.widget.CardView
    android:id="@+id/card_view"&gt;
    .....
    focusableColor="@{1}"/&gt;
  </code></pre>
  
  <p>Error encountered:</p>
  
  <p>Found data binding errors.</p>
  
  <blockquote>
    <p>****/ data binding error ****msg:Cannot find the setter for attribute ‘focusableColor’ with parameter type int on
    android.support.v7.widget.CardView.
    file:D:\…….\app\src\main\res\layout\current_task_layout.xml</p>
  </blockquote>