使用 [NSURL URLWithString:urlString] 方法生成URL時(shí)靠粪，由于urlString不符合 URL 規(guī)范導(dǎo)致生成 URL 失敗的問(wèn)題：
可以使用下面的方法先對(duì) urlString 字符串 進(jìn)行校驗(yàn)（兩種方法的區(qū)別有待探究）
方法一
使用stringByAddingPercentEncodingWithAllowedCharacters:
NSString *urlStr = [[NSString stringWithFormat:@"%@/%@?device=%@&sysver=%@&%@&%ld", CONFIG_URL, CONFIG_URL_KEYWORD, device, sysver, readHistoryStr, (long)TIMESTEMP] stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];
方法二
使用stringByAddingPercentEscapesUsingEncoding:
NSString *urlStr = [[NSString stringWithFormat:@"%@/%@?device=%@&sysver=%@&%@&%ld", CONFIG_URL, CONFIG_URL_KEYWORD, device, sysver, readHistoryStr, (long)TIMESTEMP] stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
