启用/禁用UIBUTTON取决于Uitextfield中文本的长度

Question

i有一个包含3个静态单元格的tableViewController。每个小区都有一个UITEXTFIELD。

我正在尝试计算每个文本字段中的文本长度以启用或禁用一个按钮。

为此，我正在使用textfield委托方法

-textField:shouldChangeCharactersInRange:replacementString:

但是我无法获得正确的值，例如，在长度超过6个字母时，我想在密码字段中启用按钮，并且在长度小于6个字母时禁用。

当前我无法获得正确的长度，例如，要禁用密码字段中的按钮，我需要触及3个字符，否则它不会被禁用。这对我来说是错误的，因为字符小于6时必须禁用按钮。

这是我的代码，您可以解释我错了吗？

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
     if ([self.passwordTextField.text length] >6 && [self.nameTextField.text length] >2 && [self.emailTextField.text length] >2) [self.stepCompleted setEnabled:YES];
     else if ([self.passwordTextField.text length]  <6 || [self.nameTextField.text length] <2 || [self.emailTextField.text length] <2) [self.stepCompleted setEnabled:NO];

    return YES;
}

Answer 1

首先，您需要检查textfield == self.passwordTextField或任何其他TextField是否包含您的条件。

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    if (string==nil || [string isEqualToString:@""] || [string isKindOfClass:[NSNull class]] || string.length < 1)
    {
        if([self.nameTextField.text length] < 2 || [self.emailTextField.text length] < 2 || [self.passwordTextField.text length] < 6)
        {
            [self.stepCompleted setEnabled:NO];
        }
    }
    else if(textField == self.passwordTextField && [self.passwordTextField.text length] > 6)
    {
        if([self.nameTextField.text length] > 2 && [self.emailTextField.text length] > 2)
        {
            [self.stepCompleted setEnabled:YES];
        }
        else
        {
            [self.stepCompleted setEnabled:NO];
        }
    }
    else if(textField == self.nameTextField && [self.nameTextField.text length] > 2)
    {
        if([self.passwordTextField.text length] > 6 && [self.emailTextField.text length] > 2)
        {
            [self.stepCompleted setEnabled:YES];
        }
        else
        {
            [self.stepCompleted setEnabled:NO];
        }
    }
    else if(textField == self.emailTextField && [self.emailTextField.text length] > 2)
    {
        if([self.nameTextField.text length] > 2 && [self.passwordTextField.text length] > 6)
        {
            [self.stepCompleted setEnabled:YES];
        }
        else
        {
            [self.stepCompleted setEnabled:NO];
        }
    }
    return YES;
}

Answer 2

嗨，找到解决此问题的解决方案。如果我们需要在多个UITextField中建立最小数量的字符数量，我们可以为文本场所建立最小限制，该限制使我们感兴趣并控制该方法中其余文本场的行为...

es ..我们有3个UITextField 名称 - 电子邮件 - 密码

在此示例中，如果文本字段具有最低字符

，我们希望启用或禁用一个按钮

-(BOOL)textFieldShouldClear:(UITextField *)textField {
    [button setEnabled:NO];
    return YES;
}
-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    // Otteniamo il numero di caratteri corretti
    NSString *characters = [textField.text stringByReplacingCharactersInRange:range withString:string];
    int minimumCharacter = 2;
    int minimumCharacterForPassoword = 6;
     // Identifichiamo la textField Generica con la textField che andremo ad utilizzare inoltre aggiungiamo anche il numero di caratteri MINIMI che vogliamo utilizzare per attivare il bottone Continua e quindi consentire all'utente di proseguire con la registrazione, altrimenti, se non tutti i requisiti delle textField vengono soddisfatti disabilitiamo il pulsante Continua fino a quando tutti campi non saranno completati
    // NAME
    if (textField == self.firstNameTextField) {
        if  (characters.length >= minimumCharacter) {
            if ((self.passwordTextField.text.length +1) > minimumCharacterForPassoword && (self.emailTextField.text.length +1) > minimumCharacter) [_stepCompletedButton setEnabled:YES];
            else [_stepCompletedButton setEnabled:NO];
        }
        else [_stepCompletedButton setEnabled:NO];
    }
    // EMAIL
    if (textField == self.emailTextField) {
        if  (characters.length >= minimumCharacter) {
            if ((self.passwordTextField.text.length +1) > minimumCharacterForPassoword && (self.firstNameTextField.text.length +1) > minimumCharacter) [_stepCompletedButton setEnabled:YES];
            else [_stepCompletedButton setEnabled:NO];
        }
        else [_stepCompletedButton setEnabled:NO];
    }
    // PASSWORD
    if (textField == self.passwordTextField) {
        if  (characters.length >= minimumCharacterForPassoword) {
            if ((self.firstNameTextField.text.length +1) > minimumCharacter && (self.emailTextField.text.length +1) > minimumCharacter) [_stepCompletedButton setEnabled:YES];
            else [_stepCompletedButton setEnabled:NO];
        }
        else [_stepCompletedButton setEnabled:NO];
    }
    return YES;
}