How to solve error: Could not find method onClick(View) in a parent or ancestor Context for android:onClick

Question

I have seen that there's been some similar questions but the answers to those haven't helped me so far. The full error:

java.lang.IllegalStateException: Could not find method onClick(View) in a parent or ancestor Context for android:onClick attribute defined on view class android.support.v7.widget.AppCompatButton with id 'button_random'

The class (StartActivity.java):

public class StartActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_start);
    }

    public void onClick(View v) {
        Log.d("DEBUG", "CLICKED " + v.getId());
    }

}

The XML (activity_start.xml):

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Random Game"
        android:id="@+id/button_random"
        android:layout_gravity="center_horizontal"
        android:onClick="onClick" />
</LinearLayout>

I have added the activity to the AndroidManifest.xml. I have similar activities that work in the same way and I don't have any problems with those...

Does anyone see something where I am missing something or have made a mistake?

Answer 1

In my case I missed closing bracket at the end.

android:onClick="@{(v) -> CommentHandler.selectGallery(v)".

It should be like this.
        android:onClick="@{(v) -> CommentHandler.selectGallery(v)}".

Answer 2

Please rename onClick method to anything other than that, Android thinks you are calling the internal onClick from View.java exposed via OnClickListener interface

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Random Game"
    android:id="@+id/button_random"
    android:layout_gravity="center_horizontal"
    android:onClick="myOnClick" />

and in your Activity

public class StartActivity extends AppCompatActivity {

        @Override
        protected void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.activity_start);
        }

        public void myOnClick(View v) {
          Log.d("DEBUG", "CLICKED " + v.getId());
        }
}

You can check the View documentation here