objective-c - 在目标 C 中使用正则表达式从 url 获取 Vimeo clip_id

Question

谁能告诉我如何使用 Obj C 正则表达式从 Vimeo url 中提取 clip_id？

http://vimeo.com/moogaloop.swf?clip_id=12050952&server=vimeo.com&show_title=1&show_byline=1&show_portrait=0&color=56872c&fullscreen=1

我想提取12050952。

谢谢。

Answer 1

你可以用这个模式做到这一点：

(?<=clip_id=)\d+

它正在使用积极的向后看。

演示：示例

Answer 2

我正在使用实用程序类 URLParser & 它简单明了。

URLParser *parser = [[[URLParser alloc] initWithURLString:url] autorelease];
NSString *videoId = [parser valueForVariable:@"clip_id"];  

这是 URLParser 类

#import <Foundation/Foundation.h>

@interface URLParser : NSObject {
    NSArray *variables;
}

@property (nonatomic, retain) NSArray *variables;

- (id)initWithURLString:(NSString *)url;
- (NSString *)valueForVariable:(NSString *)varName;

@end

    @implementation URLParser
@synthesize variables;

- (id) initWithURLString:(NSString *)url{
    self = [super init];
    if (self != nil) {
        NSString *string = url;
        NSScanner *scanner = [NSScanner scannerWithString:string];
        [scanner setCharactersToBeSkipped:[NSCharacterSet characterSetWithCharactersInString:@"&?"]];
        NSString *tempString;
        NSMutableArray *vars = [NSMutableArray new];
        [scanner scanUpToString:@"?" intoString:nil];       //ignore the beginning of the string and skip to the vars
        while ([scanner scanUpToString:@"&" intoString:&tempString]) {
            [vars addObject:[tempString copy]];
        }
        self.variables = vars;
        [vars release];
    }
    return self;
}

- (NSString *)valueForVariable:(NSString *)varName {
    for (NSString *var in self.variables) {
        if ([var length] > [varName length]+1 && [[var substringWithRange:NSMakeRange(0, [varName length]+1)] isEqualToString:[varName stringByAppendingString:@"="]]) {
            NSString *varValue = [var substringFromIndex:[varName length]+1];
            return varValue;
        }
    }
    return nil;
}

- (void) dealloc{
    self.variables = nil;
    [super dealloc];
}

@end