使用NSNotification将NSString变量传递给其他类

// 创建一个NSNotification对象
NSNotification *notification = [NSNotification notificationWithName:@"MyNotification" object:nil];

// 创建一个NSString对象并设置其值
NSString *myString = @"Hello World!";

// 将NSString对象添加到通知中
[notification setValue:myString forKey:@"myString"];

// 将通知添加到通知中心中
[[NSNotificationCenter defaultCenter] postNotification:notification];

// 创建一个NSNotification对象
NSNotification *notification = [NSNotification notificationWithName:@"MyNotification" object:self];

// 获取通知中传递的NSString变量
NSString *myString = [notification valueForKey:@"myString"];

// 输出结果
NSLog(@"Received notification with string: %@", myString);