小编Pop*_*eye的帖子

说我想要后退按钮@"Back"而不是标题UIViewController

这会奏效

self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Back" style:UIBarButtonItemStyleBordered target:nil action:nil];

一个更明智的选择是这个

self.navigationItem.backBarButtonItem.title = @"Back";

但事实并非如此.

为什么？

什么是synchronized？

它是干什么用的？

java synchronized和objective-c 之间有什么区别@synchronized？

我一直在看一些代码,并且遇到了->正在使用的符号,就像obj->method(argument);我做了一些研究,发现它基本上是一样的,[obj method:argument];但我不确定究竟->是什么或做了什么.

所以我的问题是,->符号在objective-c中意味着什么？

view和viewcontroller是分开的.我已经尝试过NSUserDefaults它不起作用了.

[[NSUserDefaults standardUserDefaults] setValue:BOOLCondition forKey:@"YES"];
[[NSUserDefaults standardUserDefaults] synchronize];

它表示bool到id的影响转换不允许使用arc

如何传递bool值

*****查看viewcontroller而不是viewcontroller到viewcontroller

我需要帮助使用objective-c解析json

这是我的json:

{
    "days": [
        {
            "reference": "13L6-A67-1",
            "period": "",
            "dayinit": "4",
            "hourinit": "9",
            "minuteinit": "30",
            "dayend": "4",
            "hourend": "10",
            "minuteend": "30",
            "totalattendance": "5",
            "currentattendance": "5",
            "teacher_surname": "jones",
            "teacher_forenames": "Carol",
            "room": "C109"
        },
        {
            "reference": "13NAPUSD-A1",
            "period": "",
            "dayinit": "3",
            "hourinit": "10",
            "minuteinit": "45",
            "dayend": "3",
            "hourend": "11",
            "minuteend": "45",
            "totalattendance": "3",
            "currentattendance": "3",
            "teacher_surname": "Carol",
            "teacher_forenames": "Nicola",
            "room": "M139"
        },
        {
            "reference": "13NASUWO-X1",
            "period": "",
            "dayinit": "3",
            "hourinit": "14",
            "minuteinit": "40",
            "dayend": "3",
            "hourend": "15",
            "minuteend": "5",
            "totalattendance": "0", …