小编Pip*_*ipo的帖子

我正在尝试实现一个使用RestKit的iOS应用程序.在我到目前为止看到的所有示例中,以下代码用于创建URL:

NSURL *baseURL = [NSURL URLWithString:@"https://api.service.com/v1"];
NSURL *relativeURL = [NSURL URLWithString:@"/files/search" relativeToURL:baseURL];

但随后[relativeURL absoluteString]会回来https://api.service.com/files/search.

所以我尝试了一些例子:

NSURL *baseURL1 = [NSURL URLWithString:@"https://api.service.com/v1/"];
NSURL *baseURL2 = [NSURL URLWithString:@"https://api.service.com/v1"];
NSURL *baseURL3 = [NSURL URLWithString:@"/v1" relativeToURL:[NSURL URLWithString:@"https://api.service.com"]];

NSURL *relativeURL1 = [NSURL URLWithString:@"/files/search" relativeToURL:baseURL1];
NSURL *relativeURL2 = [NSURL URLWithString:@"/files/search" relativeToURL:baseURL2];
NSURL *relativeURL3 = [NSURL URLWithString:@"/files/search" relativeToURL:baseURL3];
NSURL *relativeURL4 = [NSURL URLWithString:@"files/search" relativeToURL:baseURL1];
NSURL *relativeURL5 = [NSURL URLWithString:@"files/search" relativeToURL:baseURL2];
NSURL *relativeURL6 = [NSURL URLWithString:@"files/search" relativeToURL:baseURL3];

NSLog(@"1: %@", [relativeURL1 absoluteString]);
NSLog(@"2: %@", [relativeURL2 absoluteString]); …

我正在尝试使用AVFoundation框架从mp3和m4a文件中提取元数据.

这是测试代码:

+ (void)printMetadataForFileAtPath:(NSString *)path
{
    NSURL *url = [NSURL fileURLWithPath:path];
    AVAsset *asset = [AVURLAsset assetWithURL:url];
    NSArray *availableFormats = [asset availableMetadataFormats];
    NSLog(@"Available formats: %@", availableFormats);
    NSArray *iTunesMetadata = [asset metadataForFormat:AVMetadataFormatiTunesMetadata];
    for (AVMetadataItem *item in iTunesMetadata)
    {
        NSLog(@"%@ %x", item.key, [(NSNumber *)item.key integerValue]);

        if ([item.key isEqual:AVMetadataiTunesMetadataKeySongName])
        {
            NSLog(@"FOUND song name: %@", item.stringValue);
        }
    }
    NSLog(@"====================");
    NSLog(@"%@ %@ %@", AVMetadataiTunesMetadataKeySongName, AVMetadataiTunesMetadataKeyAlbum, AVMetadataiTunesMetadataKeyArtist);
}

这是输出:

Available formats: (
    "com.apple.itunes",
    "com.apple.quicktime.udta"
)
-1452383891 a96e616d
-1455336876 a9415254
1631670868 61415254
-1451789708 a9777274
-1453233054 a9616c62
-1452838288 a9677270 …

我正在尝试在UITableViewCell的imageView中显示动画的UIImage。动画图像在第一次分配后显示，但不在以后的尝试中。

这是TableViewController的代码：

#import "ViewController.h"

@interface ViewController ()
@property (nonatomic, strong) UIImage *animatedImage;
@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.animatedImage = [UIImage animatedImageNamed:@"syncing" duration:1.0];
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return 1;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static BOOL second = NO;

    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];

    if (second) {

        cell.imageView.image = nil;
        NSLog(@"Removed image");
    }
    else {

        cell.imageView.image = self.animatedImage;
        NSLog(@"Added image"); …