如何从NSURL中提取和删除方案名称？

Question

提取和删除方案名称的正确方法://是NSURL什么？

例如:

 note://Hello  ->  @"Hello"
 calc://3+4/5  ->  @"3+4/5"

所以

NSString *scheme = @"note://";
NSString *path   = @"Hello";

供以后使用:

[[NSNotificationCenter defaultCenter] postNotificationName:scheme object:path];

Answer 1

你可以这样看(大多数未经测试的代码,但你明白了):

- (BOOL)application:(UIApplication *)application handleOpenURL:(NSURL *)url
{
    NSLog(@"url: %@", url);
    NSLog(@"scheme: %@", [url scheme]);
    NSLog(@"query: %@", [url query]);
    NSLog(@"host: %@", [url host]);
    NSLog(@"path: %@", [url path]);

    NSDictionary * dict = [self parseQueryString:[url query]];
    NSLog(@"query dict: %@", dict);
}

所以你可以这样做:

NSString * strNoURLScheme = 
 [strMyURLWithScheme stringByReplacingOccurrencesOfString:[url scheme] withString:@""];

NSLog(@"URL without scheme: %@", strNoURLScheme);

parseQueryString

- (NSDictionary *)parseQueryString:(NSString *)query
{
    NSMutableDictionary *dict = [[[NSMutableDictionary alloc] initWithCapacity:6] autorelease];
    NSArray *pairs = [query componentsSeparatedByString:@"&"];

    for (NSString *pair in pairs) {
        NSArray *elements = [pair componentsSeparatedByString:@"="];
        NSString *key = [[elements objectAtIndex:0] stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
        NSString *val = [[elements objectAtIndex:1] stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];        
        [dict setObject:val forKey:key];
    }
    return dict;
}

Answer 2

我的倾向是滚动你自己的字符串搜索:

NSRange dividerRange = [urlString rangeOfString:@"://"];
NSUInteger divide = NSMaxRange(dividerRange);
NSString *scheme = [urlString substringToIndex:divide];
NSString *path = [urlString substringFromIndex:divide];

这就是你所要求的非常直接的方式,将URL分成一半.要获得更高级的处理,您必须提供更多详细信息.

Answer 3

只需使用 NSURL 的 API 即可：resourceSpecifier:)

并从字符串开头删除两个斜杠：

NSURL *url = [NSURL URLWithString:@"https://some.url.com/path];

url.resourceSpecifier将导致：//some.url.com/path