在使用網(wǎng)絡(luò)地址時(shí)，一般要先將url進(jìn)行encode成UTF8格式的編碼，否則在使用時(shí)可能報(bào)告網(wǎng)址不存在的錯(cuò)誤，這時(shí)就需要進(jìn)行轉(zhuǎn)換。
1.轉(zhuǎn)換函數(shù)：
NSString *urlString = [NSString stringWithFormat:@"http://www.baidu.com"];
NSString *encodedString = (NSString *)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,(CFStringRef)urlString,NULL,NULL,kCFStringEncodingUTF8);
NSURL *url = [NSURL URLWithString:encodedString];
2.通過 C 的字符串來(lái)轉(zhuǎn)換
NSString *utf8String = @"http://www.baidu.com";
NSString *unicodeStr = [NSString stringWithCString:[utf8String UTF8String] encoding:NSUnicodeStringEncoding];
3.NSURL 中的轉(zhuǎn)換
有時(shí)候獲取的url中的中文等字符是亂碼，網(wǎng)頁(yè)內(nèi)容也是亂碼，需要進(jìn)行一下轉(zhuǎn)碼才能正確識(shí)別NSString，可以用下面的方法
- （nullable NSString *）stringByAddingPercentEscapesUsingEncoding：（NSStringEncoding）enc
- （nullable NSString *）stringByReplacingPercentEscapesUsingEncoding：（NSStringEncoding）enc
// 1.創(chuàng)建 NSURL 對(duì)象
// (1)獲取 urlString
NSString *urlString = [NSString stringWithFormat:@"http://www.baidu.com"];
(2)編碼轉(zhuǎn)換
// NSString *newStr = [urlString stringByReplacingEscapesUsingEncoding:NSUTF8StringEncoding];
NSString *newStr = [urlString stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url = [NSURL URLWithString:newStr];
// 2.創(chuàng)建 NSURLRequest 請(qǐng)求對(duì)象
NSURLRequest *request = [NSURLRequest requestWithURL:url];
4.以上兩種方法9.0中已經(jīng)棄用了，可以使用以下的方法來(lái)代替
- (nullable NSString *)stringByAddingPercentEncodingWithAllowedCharacters:(NSCharacterSet)allowedCharacters
NS_AVAILBLE(10_9,7_0);
@property(nullable,readonly,copy)NSString *stringByRemovingPercentEncoding NS_AVAILABLE(10_9,7_0);
NSString *urlString = [NSString stringWithFormat:@"http://www.baidu.com"];
// 編碼轉(zhuǎn)換
NSString *newStr = ursString.stringByRemovingPercentEncoding;
NSURL *url = [NSURL URLWithString:newStr];
// 創(chuàng)建 NSURLRequest 請(qǐng)求對(duì)象
NSURLRequest *request = [NSURLRequest requestWithURL:url];
