Using custom fonts, icons can be displayed in Java code, but not in XML
          Drawable drawable_custom = new IconicsDrawable(this)
                .icon(Cniao5Font.Icon.zhu__denglong)
                .color(Color.GREEN)
                .sizeDp(150);

        ((ImageView) this.findViewById(R.id.image_custom)).setImageDrawable(drawable_custom);   √

      <TextView
           android:layout_width="50dp"
           android:layout_height="50dp"
           android:text="自定义字体{zhu_denglong}" />   ×
