Question

以下是附加到从NSUserDefaults中提取的布尔值的一堆社交媒体名称。在上一个视图中，用户可以使用UISwitch来确定布尔变量的值。在这里，我只希望仅显示用户之前已打开的社交媒体（BOOL YES）。但是，当我记录可变数组时，它甚至不输出。就目前而言，阵列＆＃34; medias＆＃34;相应地输出1和0。字典会更好吗？

ViewController.m

self.oneTableView.dataSource = self;
self.oneTableView.delegate = self;

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
NSNumber *facebook = [NSNumber numberWithBool:[prefs boolForKey:@"facebook"]];
NSNumber *twitter = [NSNumber numberWithBool:[prefs boolForKey:@"twitter"]];
NSNumber *instagram = [NSNumber numberWithBool:[prefs boolForKey:@"instagram"]];
NSNumber *tumblr = [NSNumber numberWithBool:[prefs boolForKey:@"tumblr"]];
NSNumber *gmail = [NSNumber numberWithBool:[prefs boolForKey:@"gmail"]];
NSNumber *linkedin = [NSNumber numberWithBool:[prefs boolForKey:@"linkedin"]];
NSNumber *github = [NSNumber numberWithBool:[prefs boolForKey:@"github"]];
NSNumber *youtube = [NSNumber numberWithBool:[prefs boolForKey:@"youtube"]];
NSNumber *vine = [NSNumber numberWithBool:[prefs boolForKey:@"vine"]];
NSNumber *soundcloud = [NSNumber numberWithBool:[prefs boolForKey:@"soundcloud"]];

NSArray *medias = @[facebook, twitter, instagram, tumblr, gmail, linkedin, github, youtube, vine, soundcloud];

NSLog(@"%@", medias);
int i;

NSMutableArray *includedMedias = [[NSMutableArray alloc] init];

for (i=0; i <= 10; i+=1) {
    if ([medias[i] intValue] == 1) {
        [includedMedias addObject:medias[i]];
    }else{
        return;
    }
}
NSLog(@"Included Media: %@", includedMedias);
self.tableData = [includedMedias mutableCopy];
self.oneTableView.editing = YES;

修改

ViewController.m（来自存储密钥的上一个视图控制器）：

- (void)viewDidLoad
{
    [super viewDidLoad];

    NSDictionary *socialValues = @{@"facebook": @NO,
                                   @"twitter": @NO,
                                   @"instagram": @NO,
                                   @"tumblr": @NO,
                                   @"gmail": @NO,
                                   @"linkedin": @NO,
                                   @"github": @NO,
                                   @"youtube": @NO,
                                   @"vine": @NO,
                                   @"soundcloud": @NO
                                   };
}

- (void)setupOneCell:(setupOneCell *)cell switchValueDidChange:(BOOL)switchValue {
    NSIndexPath *indexPath = [self.oneTableView indexPathForCell:cell];
    NSString *label = [self.medias[indexPath.row] socialMedia];

    NSString *newLabel = [label.lowercaseString stringByReplacingOccurrencesOfString:@" " withString:@""];

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    [self.socialValues setValue:[NSNumber numberWithBool:switchValue] forKey:newLabel];

    [defaults setObject:self.socialValues forKey:@"valueDict"];

    [defaults synchronize];
}

ViewController.m（从UserDefaults中提取数据）：

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.oneTableView.dataSource = self;
    self.oneTableView.delegate = self;
    NSMutableArray *includedMedias = [[NSMutableArray alloc] init];

    NSDictionary *mediaDict = [[NSUserDefaults standardUserDefaults] dictionaryForKey:@"valueDict"];
    for (NSString *key in mediaDict.allKeys) {
        if ([mediaDict[key] intValue] == 1) {
            [includedMedias addObject:key];
        }
    }
}

Answer 1

代码的问题是这部分

}else{
    return;
}

只要该代码找到未选中的内容，它就会从方法返回，因此永远不会到达NSLog或mutableCopy。

话虽如此，您可以通过创建一个媒体名称数组来简化代码，然后通过迭代来创建includedMedias数组。

self.oneTableView.dataSource = self;
self.oneTableView.delegate = self;

NSArray *medias = @[@"facebook", @"twitter", @"instagram", @"tumblr", @"gmail",
                    @"linkedin", @"github", @"youtube", @"vine", @"soundcloud"];

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

NSMutableArray *includedMedias = [[NSMutableArray alloc] init];

for ( NSString *media in medias )
{
    if ( [prefs boolForKey:media] )
        [includedMedias addObject:media];
}

NSLog(@"Included Media: %@", includedMedias);
self.tableData = [includedMedias mutableCopy];
self.oneTableView.editing = YES;

Answer 2

最好让您的用户默认值存储一个字典，其中的键将是媒体名称，并且值将是BOOL值的NSNumbers。然后，您可以遍历键（从allKeys方法接收）并将键字符串添加到可变数组中（如果与该键关联的值为1）。

    NSMutableArray *includedMedias = [[NSMutableArray alloc] init];
    NSDictionary *mediaDict = [[NSUserDefaults standardUserDefaults] dictionaryForKey:@"mediaDict"];
    for (NSString *key in mediaDict.allKeys) {
        if ([mediaDict[key] intValue] == 1) {
            [includedMedias addObject:key];
        }
    }

将BOOL值为YES的项添加到UITableView

2 个答案: