First I have used default Spinner to show the data in spinner but not able to change the Font style of Spinner .So I have used Custom Spinner to show data and able to change Font style
Here is the Snapshots of Dropdown ScreenShots dropdown arrow is an image
So when I tap the dropdown I want dropdown arrow should hide. Here is the xml code
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
    <TextView
        android:id="@+id/textView1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Large Text"
        android:fontFamily="@font/montserrat_regular"
        android:textSize="@dimen/_12sdp"
        android:padding="@dimen/_5sdp"
        android:layout_marginTop="@dimen/_1sdp"
        android:textAlignment="center"
        />
</LinearLayout>
Here is activity xml code
<Spinner
    style="@style/SpinnerTheme"
    android:id="@+id/languageDropdown"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginEnd="8dp"
    android:layout_marginStart="8dp"
    android:layout_marginTop="16dp"
    android:background="@null"
    android:entries="@array/Languages"
    android:spinnerMode="dropdown"
    android:textAlignment="center"
    android:gravity="center"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.501"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/relativeLayout15"
  />
<ImageButton
    android:layout_width="10dp"
    android:layout_height="6dp"
    android:layout_alignParentBottom="true"
    android:layout_marginEnd="8dp"
    android:layout_marginStart="33dp"
    android:layout_marginTop="29dp"
    android:layout_toEndOf="@+id/languageDropdown"
    android:background="@null"
    android:scaleType="fitCenter"
    android:src="@drawable/dropdownarrow"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.589"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/relativeLayout15" />
private class MyArrayAdapter extends BaseAdapter {
private LayoutInflater mInflater;
public MyArrayAdapter(LoginActivity con) {
    // TODO Auto-generated constructor stub
    mInflater = LayoutInflater.from(con);
}
@Override
public int getCount() {
    // TODO Auto-generated method stub
    return spinnerData.length;
}
@Override
public Object getItem(int position) {
    // TODO Auto-generated method stub
    return position;
}
@Override
public long getItemId(int position) {
    // TODO Auto-generated method stub
    return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    final ListContent holder;
    View v = convertView;
    if (v == null) {
        v = mInflater.inflate(R.layout.my_spinner_style, null);
        holder = new ListContent();
        holder.name = (TextView) v.findViewById(R.id.textView1);
        v.setTag(holder);
    } else {
        holder = (ListContent) v.getTag();
    }
  //  holder.name.setTypeface(myFont);
    holder.name.setText("" + spinnerData[position]);
    return v;
}
}
static class ListContent {
TextView name;
}
 
     
     
    