使用NSClassFromString

使用NSClassFromString可以直接从字符串初始化出对象出来,即使不引用头文件也没关系,以下是源码:

AppDelegate.m

////  AppDelegate.m//  Class////  Copyright (c) 2014年 Y.X. All rights reserved.//#import "AppDelegate.h"@implementation AppDelegate- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];        Class aClass                   = NSClassFromString(@"RootViewController");    UIViewController *CV           = [[aClass alloc] init];    self.window.rootViewController = CV;        self.window.backgroundColor    = [UIColor whiteColor];    [self.window makeKeyAndVisible];    return YES;}@end

////  RootViewController.m//  Class////  Copyright (c) 2014年 Y.X. All rights reserved.//#import "RootViewController.h"@interface RootViewController ()@end@implementation RootViewController- (void)viewDidLoad{    [super viewDidLoad];    self.view.backgroundColor = [UIColor redColor];}@end

改进点的方式(直接改装成为category):

NSString+CreateClass.h 与 NSString+CreateClass.m

////  NSString+CreateClass.h//  Class////  Copyright (c) 2014年 Y.X. All rights reserved.//#import 
    
     @interface NSString (CreateClass)- (Class)toClass;@end
    

////  NSString+CreateClass.m//  Class////  Copyright (c) 2014年 Y.X. All rights reserved.//#import "NSString+CreateClass.h"@implementation NSString (CreateClass)- (Class)toClass{    return NSClassFromString(self);}@end

-备注-

这种用法是有着缺陷的呢:

这是在运行时的时候检测出来的,很不保险的说.