iphone：Settings.bundle 返回空值

Question

我使用的是 xCode 3.2，然后移至 xCode 4.2 并从 Settings.bundle 获取一些值......它工作正常。

虽然我需要编辑 Settings.bundle 中的一些值，但 Root.plist 文件没有显示，所以我按照以下步骤操作，但没有对文件进行任何更改。

1) Click on the Settings.Bundle file, go over to the utilities window,
and look in the File Inspector.
2) Using the drop-down, change the file type to 'Application Bundle'

之后我可以看到 Root.plist 但现在无法在应用程序中获取它的值。实际上得到 Null 而不是 value。

下面是Settings.bundle的代码和图片

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
host = [defaults stringForKey:@"meter_preference"];
if(host == nil)
{
    host = @"10.20.20.1";
    DDLogError(@"Meter host is nil from NSUserDefaults, defaulting to %@", host);
}

Answer 1

从你的代码中，试试这个想法..

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    host = [defaults stringForKey:@"meter_preference"];
    if(!host == nil)
    {
        host = @"10.20.20.1";
        DDLogError(@"Meter host is nil from NSUserDefaults, defaulting to %@", host);
    }

或

查看此链接可能会对您有所帮助...

iPhone - reading Setting.bundle returns wrong values

NSUserDefaults Settings Bundle Plist

Answer 2

我得到了解决方案，只需在 applicationDidFinishLaunchingWithOptions 中调用以下代码来初始化用户默认值。它有效

将第一行中的somePropertyYouExpect 替换为您存储在用户默认值中的属性。

if (![[NSUserDefaults standardUserDefaults] objectForKey:@"somePropertyYouExpect"])  {

    NSString  *mainBundlePath = [[NSBundle mainBundle] bundlePath];
    NSString  *settingsPropertyListPath = [mainBundlePath
                                           stringByAppendingPathComponent:@"Settings.bundle/Root.plist"];

    NSDictionary *settingsPropertyList = [NSDictionary 
                                          dictionaryWithContentsOfFile:settingsPropertyListPath];

    NSMutableArray      *preferenceArray = [settingsPropertyList objectForKey:@"PreferenceSpecifiers"];
    NSMutableDictionary *registerableDictionary = [NSMutableDictionary dictionary];

    for (int i = 0; i < [preferenceArray count]; i++)  { 
        NSString  *key = [[preferenceArray objectAtIndex:i] objectForKey:@"Key"];

        if (key)  {
            id  value = [[preferenceArray objectAtIndex:i] objectForKey:@"DefaultValue"];
            [registerableDictionary setObject:value forKey:key];
        }
    }

    [[NSUserDefaults standardUserDefaults] registerDefaults:registerableDictionary]; 
    [[NSUserDefaults standardUserDefaults] synchronize]; 
}