我需要解析像这样的URL字符串：
&ad_eurl=http://www.youtube.com/video/4bL4FI1Gz6s&hl=it_IT&iv_logging_level=3&ad_flags=0&endscreen_module=http://s.ytimg.com/yt/swfbin/endscreen-vfl6o3XZn.swf&cid=241&cust_gender=1&avg_rating=4.82280613104
cid=241和&avg_rating=4.82280613104这样的单个部分。我一直在使用substringWithRange:来做这个，但是值会以随机顺序返回，这会搞乱它。是否有任何类可以轻松解析，使您基本上可以将其转换为NSDictionary以便能够读取键的值（例如ValueForKey：cid应返回241）。还是有比使用NSMakeRange获取子字符串更容易解析的方法吗？我也在https://dev59.com/I2865IYBdhLWcg3wFqdV#26406478中回答了这个问题。
你可以在URLComponents中使用queryItems。
当您获取此属性的值时，
NSURLComponents类会解析查询字符串，并按照出现在原始查询字符串中的顺序返回一个NSURLQueryItem对象数组，每个对象表示单个键值对。
let url = "http://example.com?param1=value1¶m2=param2"
let queryItems = URLComponents(string: url)?.queryItems
let param1 = queryItems?.filter({$0.name == "param1"}).first
print(param1?.value)
或者，您可以在URL上添加一个扩展名来使事情变得更加容易。
extension URL {
var queryParameters: QueryParameters { return QueryParameters(url: self) }
}
class QueryParameters {
let queryItems: [URLQueryItem]
init(url: URL?) {
queryItems = URLComponents(string: url?.absoluteString ?? "")?.queryItems ?? []
print(queryItems)
}
subscript(name: String) -> String? {
return queryItems.first(where: { $0.name == name })?.value
}
}
您可以通过参数名称访问该参数。
let url = URL(string: "http://example.com?param1=value1¶m2=param2")!
print(url.queryParameters["param1"])
编辑（2018年6月）：这个答案更好。苹果在iOS 7中添加了NSURLComponents。
我会创建一个字典，使用以下代码获取键值对数组：
NSMutableDictionary *queryStringDictionary = [[NSMutableDictionary alloc] init];
NSArray *urlComponents = [urlString componentsSeparatedByString:@"&"];
然后填充字典：
for (NSString *keyValuePair in urlComponents)
{
NSArray *pairComponents = [keyValuePair componentsSeparatedByString:@"="];
NSString *key = [[pairComponents firstObject] stringByRemovingPercentEncoding];
NSString *value = [[pairComponents lastObject] stringByRemovingPercentEncoding];
[queryStringDictionary setObject:value forKey:key];
}
您可以使用以下查询：
[queryStringDictionary objectForKey:@"ad_eurl"];
这段代码未经测试，建议进行更多的错误测试。
虽然我有点晚了，但是目前为止提供的答案都不符合我的需求。您可以使用以下代码片段：
NSMutableDictionary *queryStrings = [[NSMutableDictionary alloc] init];
for (NSString *qs in [url.query componentsSeparatedByString:@"&"]) {
// Get the parameter name
NSString *key = [[qs componentsSeparatedByString:@"="] objectAtIndex:0];
// Get the parameter value
NSString *value = [[qs componentsSeparatedByString:@"="] objectAtIndex:1];
value = [value stringByReplacingOccurrencesOfString:@"+" withString:@" "];
value = [value stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
queryStrings[key] = value;
}
url是您要解析的URL。您可以在queryStrings可变字典中获取所有查询字符串，已进行转义处理。
编辑: Swift版本：
var queryStrings = [String: String]()
if let query = url.query {
for qs in query.componentsSeparatedByString("&") {
// Get the parameter name
let key = qs.componentsSeparatedByString("=")[0]
// Get the parameter value
var value = qs.componentsSeparatedByString("=")[1]
value = value.stringByReplacingOccurrencesOfString("+", withString: " ")
value = value.stringByReplacingPercentEscapesUsingEncoding(NSUTF8StringEncoding)!
queryStrings[key] = value
}
}
=直到最后解码才会出现为=。然而，它不支持没有值的查询参数。 - Borishttp://example.org/?base64=ZGF0YT1bMTUyLCAyNDI2LCAyMzE1XQ==。它将返回 ZGF0YT1bMTUyLCAyNDI2LCAyMzE1XQ 而不是 ZGF0YT1bMTUyLCAyNDI2LCAyMzE1XQ==。 当然，一些base64解码器可以正确解码，但是例如NSData initWithBase64EncodedString:options:返回空字符串而不带填充的 =。 因此，在处理具有答案代码的base64字符串时应该小心。 - khcpietrohttp://example.org/?base64=ZGF0YT1bMTUyLCAyNDI2LCAyMzE1XQ==，而应该是 http://example.org/?base64=ZGF0YT1bMTUyLCAyNDI2LCAyMzE1XQ%3D%3D，因为值应该进行 URL 编码。 - Boris对于使用iOS8及以上版本的情况，可使用NSURLComponents：
+(NSDictionary<NSString *, NSString *> *)queryParametersFromURL:(NSURL *)url {
NSURLComponents *urlComponents = [NSURLComponents componentsWithURL:url resolvingAgainstBaseURL:NO];
NSMutableDictionary<NSString *, NSString *> *queryParams = [NSMutableDictionary<NSString *, NSString *> new];
for (NSURLQueryItem *queryItem in [urlComponents queryItems]) {
if (queryItem.value == nil) {
continue;
}
[queryParams setObject:queryItem.value forKey:queryItem.name];
}
return queryParams;
}
iOS 8及以下版本：
+(NSDictionary<NSString *, NSString *> *)queryParametersFromURL:(NSURL *)url
NSMutableDictionary<NSString *, NSString *> * parameters = [NSMutableDictionary<NSString *, NSString *> new];
[self enumerateKeyValuePairsFromQueryString:url.query completionblock:^(NSString *key, NSString *value) {
parameters[key] = value;
}];
return parameters.copy;
}
- (void)enumerateKeyValuePairsFromQueryString:(NSString *)queryString completionBlock:(void (^) (NSString *key, NSString *value))block {
if (queryString.length == 0) {
return;
}
NSArray *keyValuePairs = [queryString componentsSeparatedByString:@"&"];
for (NSString *pair in keyValuePairs) {
NSRange range = [pair rangeOfString:@"="];
NSString *key = nil;
NSString *value = nil;
if (range.location == NSNotFound) {
key = pair;
value = @"";
}
else {
key = [pair substringToIndex:range.location];
value = [pair substringFromIndex:(range.location + range.length)];
}
key = [self decodedStringFromString:key];
key = key ?: @"";
value = [self decodedStringFromString:value];
value = value ?: @"";
block(key, value);
}
}
+ (NSString *)decodedStringFromString:(NSString *)string {
NSString *input = shouldDecodePlusSymbols ? [string stringByReplacingOccurrencesOfString:@"+" withString:@" " options:NSLiteralSearch range:NSMakeRange(0, string.length)] : string;
return [input stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
}
Swift 5
extension URL {
func queryParams() -> [String:String] {
let queryItems = URLComponents(url: self, resolvingAgainstBaseURL: false)?.queryItems
let queryTuples: [(String, String)] = queryItems?.compactMap{
guard let value = $0.value else { return nil }
return ($0.name, value)
} ?? []
return Dictionary(uniqueKeysWithValues: queryTuples)
}
}
如果你想在Swift中做同样的事情，你可以使用一个扩展。
extension NSURL {
func queryDictionary() -> [String:String] {
let components = self.query?.componentsSeparatedByString("&")
var dictionary = [String:String]()
for pairs in components ?? [] {
let pair = pairs.componentsSeparatedByString("=")
if pair.count == 2 {
dictionary[pair[0]] = pair[1]
}
}
return dictionary
}
}
自从iOS 8以来，您可以直接在NSURLQueryItem上使用属性name和value。
例如，如何解析URL并获取解析后键值对的特定值。
NSURLComponents *urlComponents = [NSURLComponents componentsWithURL:@"someURL" resolvingAgainstBaseURL:false];
NSArray *queryItems = urlComponents.queryItems;
NSMutableArray *someIDs = [NSMutableArray new];
for (NSURLQueryItem *item in queryItems) {
if ([item.name isEqualToString:@"someKey"]) {
[someIDs addObject:item.value];
}
}
NSLog(@"%@", someIDs);
NSURLComponents，以下简洁的扩展也可以解决问题：extension NSURLComponents {
func getQueryStringParameter(name: String) -> String? {
return (self.queryItems? as [NSURLQueryItem])
.filter({ (item) in item.name == name }).first?
.value()
}
}
`func getQueryStringParameter(name: String) -> String? {
return self.queryItems?.filter({ (item) in item.name == name }).first?.value
}` - Jedidja1.http://www.youtube.com/watch?v=VWsl7C-y7EI&feature=youtu.be
2.http://youtu.be/lOvcFqQyaDY
3.http://www.youtube.com/watch?v=VWsl7C-y7EI
NSArray *arr = [youtubeurl componentsSeparatedByString:@"v="];
NSString *youtubeID;
if([arr count]>0)
{
if([arr count]==1){
youtubeID= [[youtubeurl componentsSeparatedByString:@"/"] lastObject];
}
else{
NSArray *urlComponents = [[arr objectAtIndex:1] componentsSeparatedByString:@"&"];
youtubeID=[urlComponents objectAtIndex:0];
}
}
-(NSArray *)getDataOfQueryString:(NSString *)url{
NSArray *strURLParse = [url componentsSeparatedByString:@"?"];
NSMutableArray *arrQueryStringData = [[NSMutableArray alloc] init];
if ([strURLParse count] < 2) {
return arrQueryStringData;
}
NSArray *arrQueryString = [[strURLParse objectAtIndex:1] componentsSeparatedByString:@"&"];
for (int i=0; i < [arrQueryString count]; i++) {
NSMutableDictionary *dicQueryStringElement = [[NSMutableDictionary alloc]init];
NSArray *arrElement = [[arrQueryString objectAtIndex:i] componentsSeparatedByString:@"="];
if ([arrElement count] == 2) {
[dicQueryStringElement setObject:[arrElement objectAtIndex:1] forKey:[arrElement objectAtIndex:0]];
}
[arrQueryStringData addObject:dicQueryStringElement];
}
return arrQueryStringData;
}
这个函数只需要传入URL，就能获取查询字符串中的所有元素。
NSArray *urlComponents = [urlString componentsSeparatedByString:@"&"]; NSMutableDictionary *queryStringDictionary = [[NSMutableDictionary alloc] initWithCapacity: urlComponents.count];- adnakoNSRange range = [keyValuePair rangeOfString:@"="]; NSString *key = [keyValuePair substringToIndex:range.location]; NSString *value = [keyValuePair substringFromIndex:range.location+1];。这将使其正常运行。 - Renato Silva Das Neves