自定义视图如何访问其活动？

public interface CustomViewListener {
    void onActionPerformed();
}

private CustomViewListener mListener;

public CustomView(Context context) {
    this(context, null);
}

public CustomView(Context context, AttributeSet attrs) {
    this(context, attrs, 0);
}

public CustomView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    // ...
}

public void setCustomViewListener(CustomViewListener listener) {
    mListener = listener;
}

private void performAction() {
    if (mListener != null) {
        mListener.onActionPerformed();
    }
}

public class MainActivity extends AppCompatActivity implements CustomView.CustomViewListener {
    // ...

    @Override
    public void onActionPerformed() {
        // 处理自定义视图中的动作
    }
}

CustomView customView = findViewById(R.id.custom_view);
customView.setCustomViewListener(this);