ios-day21-01(对URL中的中文或特殊字符添加百分号转义、把经过百分号转义的URL还原)

NSString *urlStr = [NSString stringWithFormat:@"http://localhost/login.php?username=张三&password=1234"];
// 如果URL中包含中文字符串或者特殊字符(例如空格)，需要给URL添加百分号转义
urlStr = [urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

NSURL *url = [NSURL URLWithString:urlStr];

NSLog(@"urlStr:%@", urlStr);
// 打印结果：urlStr:http://localhost/login.php?username=%E5%BC%A0%E4%B8%89&password=1234

// 把经过百分号转义的URL还原
urlStr = [@"http://localhost/login.php?username=%E5%BC%A0%E4%B8%89&password=1234" stringByRemovingPercentEncoding];

NSLog(@"urlStr:%@", urlStr);
// 打印结果：urlStr:http://localhost/login.php?username=张三&password=1234