UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:@"提示" message:@"確認(rèn)退出登錄？" preferredStyle:(UIAlertControllerStyleAlert)];
 UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
 NSLog(@"點擊了Cancel");
 [alertVC dismissViewControllerAnimated:YES completion:nil];
 }];
 UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"確定" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
 NSLog(@"點擊了OK");
 [[NSUserDefaults standardUserDefaults] setObject:nil forKey:kLoginUserKey];
 [alertVC dismissViewControllerAnimated:YES completion:nil];
 }];
 //修改title
 NSMutableAttributedString *alertControllerStr = [[NSMutableAttributedString alloc] initWithString:@"提示"];
 [alertControllerStr addAttribute:NSForegroundColorAttributeName value:kMainTextColor range:NSMakeRange(0, 2)];
 [alertControllerStr addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:15] range:NSMakeRange(0, 2)];
 [alertVC setValue:alertControllerStr forKey:@"attributedTitle"];
 //修改message
 NSMutableAttributedString *alertControllerMessageStr = [[NSMutableAttributedString alloc] initWithString:@"確認(rèn)退出登錄？"];
 [alertControllerMessageStr addAttribute:NSForegroundColorAttributeName value:kSubTextColor range:NSRangeFromString(@"確認(rèn)退出登錄？")];
 [alertControllerMessageStr addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:13] range:NSRangeFromString(@"確認(rèn)退出登錄？")];
 [alertVC setValue:alertControllerMessageStr forKey:@"attributedMessage"];
 //修改按鈕字體顏色
 [cancelAction setValue:kGreenColor forKey:@"titleTextColor"];
 [okAction setValue:kGreenColor forKey:@"titleTextColor"];
 [alertVC addAction:cancelAction];
 [alertVC addAction:okAction];
 [self presentViewController:alertVC animated:YES completion:nil];