Java tutorial
//package com.java2s; import android.content.Context; public class Main { public static int getIdByName(Context context, String className, String name) { String packageName = context.getPackageName(); Class r = null; int id = 0; try { r = Class.forName(packageName + ".R"); Class[] classes = r.getClasses(); Class desireClass = null; for (int i = 0; i < classes.length; ++i) { if (classes[i].getName().split("\\$")[1].equals(className)) { desireClass = classes[i]; break; } } if (classes.length == 0) { desireClass = Class.forName(packageName + ".R$" + className); } if (desireClass != null) id = desireClass.getField(name).getInt(desireClass); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (IllegalArgumentException e) { e.printStackTrace(); } catch (SecurityException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (NoSuchFieldException e) { e.printStackTrace(); } return id; } }