在“if 语句错误”上中止 IBAction

Question

我正在尝试进行我的第一个用户注册。注册将由 4 个文本字段进行，需要用户编辑并在按下按钮 (IBAction) 后保存。当 1 个字段为空时，需要中止此 IBAction。将向用户显示警告文本，他/她需要在继续将文本数据保存到解析服务器之前纠正问题/

我已将我的 4 个 Uitextfields 连接到 .m 脚本，并且我认为我已经编写了一个很好的 if 语句。但是如何在警告文本之后停止我的脚本？

代码.M：

- (IBAction)REGISTERNEWUSER:(id)sender
{

    //DEFINE STRINGS FOR MODULE
    NSString *NICKNAME = Nickname.text;
    NSString *USERNAME = Username.text;
    NSString *PASSWORD = Password.text;
    NSString *EMAIL = Email.text;
    NSString *ERRORREGISTRATION = @"Please fill up all fields above before proceeding with the  registration...";

    //CHECK IF ALL REGISTRATION FIELDS ARE FILLED
    if ([Nickname.text length] > 0 || [Username.text length] > 0 || [Password.text length] > 0 || [Email.text length] > 0 )
    {
    }
    ErrorRegistration.text = ERRORREGISTRATION;

    //
    // METHODE NEEDS TO STOP HERE
    // BUT AT MOMENT CONTINUES TO SEND DATA TO PARSE
    //
    {

    }


    //SEND DATA TO PARSE SERVER
    PFObject *User = [PFObject objectWithClassName:@"USER"];
    [User setValue:NICKNAME forKey:@"Nickname"];
    [User setValue:USERNAME forKey:@"Username"];
    [User setValue:PASSWORD forKey:@"Password"];
    [User setValue:EMAIL forKey:@"Email"];
    [User save];
}

提前感谢您提供的任何帮助。 亲切的问候， 留置权。

Answer 1

你想要这样的东西：

if ([Nickname.text length] == 0 || [Username.text length] == 0 || [Password.text length] == 0 || [Email.text length] == 0 ) {
    // Not all fields are entered
    ErrorRegistration.text = ERRORREGISTRATION;
} else {
    // All fields are entered
    //SEND DATA TO PARSE SERVER
    PFObject *User = [PFObject objectWithClassName:@"USER"];
    [User setValue:NICKNAME forKey:@"Nickname"];
    [User setValue:USERNAME forKey:@"Username"];
    [User setValue:PASSWORD forKey:@"Password"];
    [User setValue:EMAIL forKey:@"Email"];
    [User save];
}

顺便说一句 - 修复您的大写锁定键。方法和变量名称应使用 camelCase（以小写字母开头）。类名应使用 CamelCase（以大写字母开头）。

if ([nickname.text length] == 0 || [username.text length] == 0 || [password.text length] == 0 || [email.text length] == 0 ) {
    // Not all fields are entered
    errorRegistration.text = @"Please fill up all fields above before proceeding with the  registration...";
} else {
    // All fields are entered
    //SEND DATA TO PARSE SERVER
    PFObject *user = [PFObject objectWithClassName:@"USER"];
    [user setValue:nickname.text forKey:@"Nickname"];
    [user setValue:username.text forKey:@"Username"];
    [user setValue:password.text forKey:@"Password"];
    [user setValue:email.text forKey:@"Email"];
    [user save];
}

在这种情况下不需要所有额外的变量。