iphone - 如何在 Objective-C 中解析 iframe 标签的 src 属性？

Question

我有以下字符串：

<iframe width="1280" height="720" src="http://www.youtube.com/embed/Pb55ep-DrSo?wmode=opaque&autoplay=1&fs=1&feature=oembed&showinfo=0&autohide=1&controls=0" frameborder="0" allowfullscreen></iframe>

我想提取 src 属性，但不确定如何在 Objective-C 中解析它？

Answer 1

这很丑陋，但它有效：

NSString* str = @"<iframe width=\"1280\" height=\"720\" src=\"http://www.youtube.com/embed/Pb55ep-DrSo?wmode=opaque&autoplay=1&fs=1&feature=oembed&showinfo=0&autohide=1&controls=0\" frameborder=\"0\" allowfullscreen></iframe>";
str = [str substringFromIndex:[str rangeOfString:@"src=\""].location+[str rangeOfString:@"src=\""].length];
str = [str substringToIndex:[str rangeOfString:@"\""].location ];
NSLog(@"Str %@",str);

我测试了它，它输出：

2012-08-17 09:16:55.285 TEST[24413:c07] Str http://www.youtube.com/embed/Pb55ep-DrSo?wmode=opaque&autoplay=1&fs=1&feature=oembed&showinfo=0&autohide=1&controls=0

Answer 2

这是获取 src 属性的正则表达式，如果您需要使用一些正则表达式生成器来验证它

src[\s]*=[\s]*"([^"]*)"

这是您可以在程序中使用的完整代码，

NSString *searchedString = @"<iframe width=\"1280\" height=\"720\" src=\"http://www.youtube.com/embed/Pb55ep-DrSo?wmode=opaque&autoplay=1&fs=1&feature=oembed&showinfo=0&autohide=1&controls=0\" frameborder=\"0\" allowfullscreen></iframe>";
NSError* error = nil;

NSRegularExpression* regex = [NSRegularExpression regularExpressionWithPattern:@"src[\s]*=[\s]*\"([^\"]*)\"" options:0 error:&error];
NSArray* matches = [regex matchesInString:searchedString options:0 range:NSMakeRange(0, [searchedString length])];
for ( NSTextCheckingResult* match in matches )
{
    NSString* matchText = [searchedString substringWithRange:[match range]];
    NSLog(@"match: %@", matchText);
    NSRange group1 = [match rangeAtIndex:1];
    NSLog(@"group1: %@", [searchedString substringWithRange:group1]);
}

希望这可以帮助！