Android反射drawable

private int getDrawableByReflect(String field) {
int drawable = 0;
// "cn.testreflect.R$drawable"
String pkg = MainApplication.getContext().getPackageName();
String clazz = pkg + ".R$drawable";
try {
Field f = Class.forName(clazz).getField(field);
drawable = f.getInt(field);
} catch (Exception e) {
e.printStackTrace();
}
return drawable;
}