通过String获取资源ID

 
    R.drawable drawables = new R.drawable();
    //默认的id
    int resId = 0x7f02000b;
    try {
        //根据资源的ID的变量名获得Field的对象,使用反射机制来实现的
        java.lang.reflect.Field field = R.drawable.class.getField(name);
        //取值
        resId = (Integer) field.get(drawables);
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }