C++/CLI语法错误。这是漫长的一天，我的大脑不能正常工作

Question

有人能看到这个错误吗？我得到的错误是：

1>MainForm.cpp(71)：error C2059:语法错误：‘)

1>MainForm.cpp(72)：error C2143:语法错误:缺失；'{‘之前的’

1>MainForm.cpp(75)：错误C2181:如果不匹配，则为非法

1>MainForm.cpp(75)：error C2059:语法错误：‘’

1>MainForm.cpp(76)：error C2143:语法错误:缺失；'{‘之前的’

代码：

if (oMail->From->ToString()->Contains("email@gmail.com")) //Compare to whitelist
{
                mailSend::sendMail("email@gmail.com", "Commands Accepted!", "You are on the whitelist for this server.");
}
else if () //Compare to blacklist
{
                mailSend::sendMail("email@gmail.com", "Commands Rejected!", "You are on the blacklist for this server.");
}
else () // Else do Default Behavior
{
    if (UserSettings::TheInstance2->defaultBehavior->ToString() == "Accept")
    {
                mailSend::sendMail("email@gmail.com", "Commands Accepted!", "Accepted");
    }
    else if (UserSettings::TheInstance2->defaultBehavior->ToString() == "Accept (And add to Whitelist)")
    {
                mailSend::sendMail("email@gmail.com", "Commands Accepted!", "You have been added to the whitelist for this server!");
    }
    else if (UserSettings::TheInstance2->defaultBehavior->ToString() == "Reject")
    {
                mailSend::sendMail("email@gmail.com", "Commands Rejected!", "The server admin has set the server to reject non-whitelisted addresses.");
    }
    else if (UserSettings::TheInstance2->defaultBehavior->ToString() == "Reject (And add to Blacklist)")
    {
        mailSend::sendMail("email@gmail.com", "Commands Rejected!", "The server admin has set the server to add rejected addresses to the blacklist. You are now on it.");
    }

Answer 1

你的代码写着：

else if () 

这肯定是个错误。

Answer 2

 else () 
   // ^^ Remove this.
 {
      // ....
 }

else语句不应该有()