通过反射的方法获取资源id

import android.content.Context;

public class MResource {
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) {
String classname1=classes[i].getName();
if (classname1.indexOf(className)!=-1)  //是否包含某个具体字符串
{
desireClass = classes[i];
break;
}

}
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;
}
}