Gridview按钮配置

<LinearLayout
    android:background=\"@raw/br_poster_dark\"
    android:orientation=\"vertical\"    
    android:layout_height=\"fill_parent\"
    android:layout_width=\"fill_parent\"
    android:layout_gravity=\"center\"
    android:padding=\"30dip\"     >   



            <GridView android:id=\"@+id/brgrid\"
                android:layout_width=\"fill_parent\" 
                android:layout_height=\"fill_parent\"
                android:padding=\"5dp\"
                android:columnWidth=\"90dp\"
                android:rowHeight=\"90dp\"
                android:numColumns=\"3\"
                android:gravity=\"center\"
                android:textColor=\"#ffffff\"
                />

</LinearLayout>

public View getView(int position, View convertView, ViewGroup parent) {
    try {
        final Sample sample = board.getSamples().get(position);

        if (sample != null) {
            Button button = new Button(context);
            button.setText(sample.getName());


            button.setBackgroundResource(R.drawable.roundedbutton);