NSNumber未从NSUserDefaults准确设置(NSNumber not being accurately set from NSUserDefaults)

 在ViewControllerA中，我设置以下内容： 
 
NSNumber *phaseIsKnownNSNum = 1

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:phaseIsKnownNSNum forKey:@"Phase is Known"];
[defaults synchronize];
 
 在ViewControllerB中，只要我不使用相同的“phaseIsKnownNSNum”变量名，我就可以从用户默认值中提取此值。 在ViewControllerB中按下按钮后发生以下情况： 
 
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

//using 2 instances of the standardUserDefaults, just to be sure.
NSUserDefaults *defaultsTest = [NSUserDefaults standardUserDefaults];

NSNumber *testNum = [defaultsTest objectForKey:@"Phase is Known"];

NSLog(@"in ViewControllerB, btn pressed:  test %d", [testNum intValue]);
 
 这记录“在ViewControllerB中，btn按下：测试1”。 
 
NSNumber *testNum2 = [defaultsTest objectForKey:@"Phase is Known"];

NSLog(@"in ViewControllerB, btn pressed:  test2  %d", [testNum2 intValue]);
 
 这记录“在ViewControllerB中，按下btn：test2 1” 
 
testNum = [defaults objectForKey:@"Phase is Known"];

NSLog(@"in ViewControllerB, btn pressed:  test %d", [testNum intValue]);
 
 这记录“在ViewControllerB中，btn按下：测试1” 
 
 当我在ViewControllerB中尝试使用“phaseIsKnownNSNum”时，我并不是那么幸运。 
 
//I've tried not allocating & initializing.  Gives the same issue.
NSNumber *phaseIsKnownNSNum = [[NSNumber alloc] initWithInt:1];

NSLog(@"phaseIsKnownNSNum from initialized value:  %d", [phaseIsKnownNSNum intValue]);
 
 此日志：“初始值为phaseIsKnownNSNum：1” 
 
phaseIsKnownNSNum = [defaultsTest objectForKey:@"Phase Is Known"];

NSLog(@"phaseIsKnownNSNum from defaultsTest:  %d", [phaseIsKnownNSNum intValue]);
 
 这会记录“defaultsTest：0中的phaseIsKnownNSNum”。 
 
 设置断点并检查phaseIsKnownNSNum的值，它是零。 
 
phaseIsKnownNSNum = [defaults objectForKey:@"Phase Is Known"];

NSLog(@"phaseIsKnownNSNum from defaults:  %d", [phaseIsKnownNSNum intValue]);
 
 这会记录“phaseIsKnownNSNum默认值：0”。 
 
 设置断点并检查phaseIsKnownNSNum的值，它仍然是零。 
 
 重复使用相同名称存储和检索用户默认值是否存在问题？ 我知道简单的解决方案是使用不同的变量名称。 但是，在ViewControllers C，D，E中检索此默认值，... 
 
 每次NSNumber变量名称必须不同是没有意义的。 

In ViewControllerA, I am setting the following:
 
NSNumber *phaseIsKnownNSNum = 1

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:phaseIsKnownNSNum forKey:@"Phase is Known"];
[defaults synchronize];
 
In ViewControllerB, I'm able to pull this value from user defaults as long as I don't use the same "phaseIsKnownNSNum" variable name. The following occurs after a button press in ViewControllerB:
 
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

//using 2 instances of the standardUserDefaults, just to be sure.
NSUserDefaults *defaultsTest = [NSUserDefaults standardUserDefaults];

NSNumber *testNum = [defaultsTest objectForKey:@"Phase is Known"];

NSLog(@"in ViewControllerB, btn pressed:  test %d", [testNum intValue]);
 
this logs "in ViewControllerB, btn pressed: test 1".
 
NSNumber *testNum2 = [defaultsTest objectForKey:@"Phase is Known"];

NSLog(@"in ViewControllerB, btn pressed:  test2  %d", [testNum2 intValue]);
 
this logs "in ViewControllerB, btn pressed: test2 1"
 
testNum = [defaults objectForKey:@"Phase is Known"];

NSLog(@"in ViewControllerB, btn pressed:  test %d", [testNum intValue]);
 
this logs "in ViewControllerB, btn pressed: test 1"
 
when trying to use "phaseIsKnownNSNum" in ViewControllerB, I am not so lucky.
 
//I've tried not allocating & initializing.  Gives the same issue.
NSNumber *phaseIsKnownNSNum = [[NSNumber alloc] initWithInt:1];

NSLog(@"phaseIsKnownNSNum from initialized value:  %d", [phaseIsKnownNSNum intValue]);
 
this logs: "phaseIsKnownNSNum from initialized value: 1"
 
phaseIsKnownNSNum = [defaultsTest objectForKey:@"Phase Is Known"];

NSLog(@"phaseIsKnownNSNum from defaultsTest:  %d", [phaseIsKnownNSNum intValue]);
 
this logs "phaseIsKnownNSNum from defaultsTest: 0".
 
setting a breakpoint and inspecting the value of phaseIsKnownNSNum, it is nil.
 
phaseIsKnownNSNum = [defaults objectForKey:@"Phase Is Known"];

NSLog(@"phaseIsKnownNSNum from defaults:  %d", [phaseIsKnownNSNum intValue]);
 
this logs "phaseIsKnownNSNum from defaults: 0".
 
setting a breakpoint and inspecting the value of phaseIsKnownNSNum, it is still nil.
 
Is there some issue with reusing the same name for storing and retrieving user defaults? I know the simple solution is to use a different variable name. However, this default is retrieved in ViewControllers C, D, E, ...
 
It wouldn't make sense that the NSNumber variable name would have to be different each time.

原文：https://stackoverflow.com/questions/35385734