Objective-C URL编码问题

我正在创建一个URL字符串，如下所示：

[Items appendString:[object objectForKey:@"Items"]];
[Items appendString:@"*"];
[Items deleteCharactersInRange:NSMakeRange([Items length]-1, 1)];
//This returns this: ~SEWER/FLATWORK SUPPLY & INSTALL - 25% of CONTRACT*~SEWER/FLATWORK SUPPLY & INSTALL - 75% of CONTRACT*SUMP PUMP PIT

//add Items to URL
NSString *fullURL = [NSString stringWithFormat:@"https://example.com?Items=%@, [Items stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];

但它的回报是这样的：

Items=~SEWER/FLATWORK%20SUPPLY%20&%20INSTALL%20-%2025%25%20of%20CONTRACT*~SEWER/FLATWORK%20SUPPLY%20&%20INSTALL%20-%2075%25%20of%20CONTRACT*SUMP%20PUMP%20PIT

我如何让它像这样返回：

%20%26%20

而不是

%20和
的
%20和
？
试试这个

fullURL=[fullURL stringByReplacingOccurrencesOfString:@"&" withString:@"%26"];
NSLog(@"fullURL: %@ ...", fullURL);

使用CFURLCreateStringByAddingPercentEscapes（）获取字符的UTF8stringencoding

NSString *urlString = CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (__bridge CFStringRef) Items, NULL, CFSTR("!*'();:@&=+$,/?%#[]"), kCFStringEncodingUTF8))

我认为问题是这个方法太聪明了——它只做了获得合法URL所必需的事情，而且因为您的字符串中没有问号，所以它可能认为保留符号是可以的

尝试构建整个URL并对整个URL进行转义

NSString *fullURL = [[@"https://example.com?Items=" stringByAppendingString: items]                       
                      stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

或者使用。
为什么不使用
NSMutableURL
？