仅当应用程序更新时重置特定的 NSUserDefaults 键

Question

我有两个 NSUserDefaults 键：第一个是与显示一个小介绍窗口相关的键，第二个是与更改前 3 个会话的 tableView 中的单元格背景颜色相关的键。

现在，当我更新我的应用程序时，我希望重置第二个键，以便为前 3 个会话显示不同的单元格背景颜色。

这是我在应用程序委托中的代码：（

[[NSUserDefaults standardUserDefaults] setObject: @"1.3.5" forKey:@"lastVer"];//in memory
    NSString *lastVersion = [[NSUserDefaults standardUserDefaults] objectForKey:@"lastVer"];
    NSString *version = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleVersion"];

    NSLog(@"**** Version: %@",version);

    NSNumber *runNumber = [[NSUserDefaults standardUserDefaults] objectForKey:@"runNum"]; 
   if(![lastVersion isEqualToString: version]){
        NSNumber *runNumber = [NSNumber numberWithInt:0]; 
        [[NSUserDefaults standardUserDefaults] setObject:runNumber forKey:@"runNum"]; 
    }
    else { 
        [[NSUserDefaults standardUserDefaults] setObject:[NSNumber numberWithInt:([runNumber intValue] + 1)] forKey:@"runNum"]; 
        NSLog(@"This is Run Number: %d", [runNumber intValue]);    
    }

    if (runNumber == [NSNumber numberWithInt:0]){
       [[NSUserDefaults standardUserDefaults] setObject:[NSNumber numberWithInt:([runNumber intValue] + 1)] forKey:@"runNum"]; 
        NSLog(@"Run number: %d", [runNumber intValue]);    
    }

注意：runNumber 是存储 3 个会话的单元格背景颜色的键）

它检查 lastVersion 是否等于捆绑包版本，并重置 runNum 的键（为其提供值） 0）。然后，如果 runNum 为 0，则增加 runNumbers。

但有一个问题！

当lastVersion与版本不同时，它会重置密钥，但我不知道如何再次增加runNum，而无需再次重置运行次数，因为每次打开应用程序时runNum都会被重置！

即

lastVersion = 1.3.4
version = 1.3.5
if lastVersion is different from version, then runNum == 0
and if runNum == 0, runNum = runNum + 1
//CLOSING AND REOPENING THE APP
runNum = 0 
runNum = runNum +1
//CLOSING AND REOPENING THE APP
runNum = 0
runNum = runNum + 1
//and so on..

当我关闭并重新打开应用程序时，runNum 键再次变为 0！

如何仅重置 runNum 键一次，然后再次增加它？

编辑

我做了以下更改：

NSString *lastVersion = [[NSUserDefaults standardUserDefaults] objectForKey:@"lastVer"]; 

    // get the current bundle version. 
    NSString *currentVersion = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleVersion"]; 


    NSLog(@"Last Version: %@, New Version: %@", lastVersion, currentVersion); 

    NSNumber *runNumber = [[NSUserDefaults standardUserDefaults] objectForKey:@"runNum"]; 
    NSInteger runNumberValue = [runNumber integerValue]; 


    if(![lastVersion isEqualToString: currentVersion]){ 
        NSLog(@"Last Version and Version are not same."); 
        NSNumber *runNumber = [NSNumber numberWithInt:0]; 
        [[NSUserDefaults standardUserDefaults] setObject:runNumber forKey:@"runNum"]; 
        [[NSUserDefaults standardUserDefaults] setObject:currentVersion forKey:@"lastVer"]; 
        NSLog(@"last Version is: %@",lastVersion);

    } 
    else { 
        NSLog(@"Last Version and Version are same."); 
        NSInteger newRunNumberValue = runNumberValue++; 
        if(newRunNumberValue > 2) { 
            newRunNumberValue = 0; 
        } 
        [[NSUserDefaults standardUserDefaults] setObject:[NSNumber numberWithInt:newRunNumberValue] forKey:@"runNum"]; 
    }

这是在前 3 个会话中使单元格背景发生变化的代码：

    NSString *lastVersion = [[NSUserDefaults standardUserDefaults] objectForKey:@"lastVer"]; 

// get the current bundle version. 
NSString *currentVersion = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleVersion"]; 

NSLog(@"Last Version: %@, New Version: %@", lastVersion, currentVersion); 

NSNumber *runNumber = [[NSUserDefaults standardUserDefaults] objectForKey:@"runNum"]; 

if (!runNumber) { 
    NSLog(@"**** Resetting Run Number to zero ****"); 
    NSNumber *runNumber = [NSNumber numberWithInt:0]; 
    [[NSUserDefaults standardUserDefaults] setObject:runNumber forKey:@"runNum"]; 
} else { 
    [[NSUserDefaults standardUserDefaults] setObject:[NSNumber numberWithInt:([runNumber intValue] + 1)] forKey:@"runNum"]; 
    NSLog(@"This is Run Number: %d", [runNumber intValue]); 
} 


if(![lastVersion isEqualToString: currentVersion]){ 
    NSLog(@"Last Version and Version are not same."); 
    [[NSUserDefaults standardUserDefaults] setObject:currentVersion forKey:@"lastVer"]; 
    NSLog(@"last Version is: %@",lastVersion);
    //What should i do here to make the updated app show the different cells background?
} 
else { 
    NSLog(@"Last Version and Version are same."); 
    //What should i do here to make the updated app show the different cells background?
}

现在：当用户下载应用程序时，如何使应用程序显示不同的单元格背景第一次（3 个会话）以及用户更新应用程序时（即使在 N 个会话之后）？我被困在这里了。

有什么想法吗？

Answer 1

我自己解决了！

 if(![lastVersion isEqualToString: currentVersion]){ 
        NSLog(@"Last Version and Version are not same."); 
        [[NSUserDefaults standardUserDefaults] setObject:currentVersion forKey:@"lastVer"]; 
        NSLog(@"last Version is: %@",lastVersion);
        NSNumber *runNumber = [NSNumber numberWithInt:0]; 
        [[NSUserDefaults standardUserDefaults] setObject:runNumber forKey:@"runNum"]; 
        NSLog(@"runNumber is: %d",[runNumber intValue]);

    } 
    else { 
        NSLog(@"Last Version and Version are same."); 
        [[NSUserDefaults standardUserDefaults] setObject:[NSNumber numberWithInt:([runNumber intValue] + 1)] forKey:@"runNum"]; 
        NSLog(@" Run Number: %d", [runNumber intValue]);    
    }

Answer 2

当上一个版本与当前版本不相等时，您应该重置运行号。这将是新版本首次运行时的情况。因此，在将用户默认值更新为捆绑包中的版本号之前，请重置此时的运行号。

Answer 3

虽然你的问题不是很清楚，但我只是尽力根据我能理解的内容提供帮助。请编辑您的问题，以便更清楚地描述您的问题。

您可以记录您的 NSString *version 的值吗？

即紧接着：

NSString *version = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleVersion"];

put a

NSLog(@"version %@", version);

这应该确保你的是否

if([lastVersion isEqualToString: version]){ 
...
}

被执行。

此外，您不必简单地从 NSUserDefaults 中删除密钥来更新它。您可以安全地从代码中删除这一行：

[[NSUserDefaults standardUserDefaults] removeObjectForKey:@"runNum"];

只需进行这些更改，然后让我知道它是否有效。