Question

我有问题。
我有四个文本字段，但我不知道如何检查输入字符串的文本字段

nameField不超过10个字符串
ageField检查是否为数字
sexField检查男性或女性

这是我的代码：

- (IBAction)addComment:(id)sender {

    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Commend" message:nil preferredStyle:UIAlertControllerStyleAlert];

    [alertController addTextFieldWithConfigurationHandler:^(UITextField *textField) {
        textField.placeholder = @"Please input your name:";
    }];
    [alertController addTextFieldWithConfigurationHandler:^(UITextField *textField) {
        textField.placeholder = @"Please input your age:";
    }];
    [alertController addTextFieldWithConfigurationHandler:^(UITextField *textField) {
        textField.placeholder = @"Please input your sex:";
    }];
    [alertController addTextFieldWithConfigurationHandler:^(UITextField *textField) {
        textField.placeholder = @"Please input your commend:";
    }];

    UIAlertAction *sendAction = [UIAlertAction actionWithTitle:@"send" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {

        UITextField *nameField = alertController.textFields[0];
        UITextField *ageField = alertController.textFields[1];
        UITextField *sexField = alertController.textFields[2];
        UITextField *commentField = alertController.textFields[3];


        UIAlertController *successAlertController = [UIAlertController alertControllerWithTitle:@"Alert" message:@"Success" preferredStyle:UIAlertControllerStyleAlert];
        UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

            [self.navigationController popViewControllerAnimated:YES];

        }];
        [successAlertController addAction:okAction];
        [self presentViewController:successAlertController animated:YES completion:nil];


    }];

    [alertController addAction:sendAction];
    [self presentViewController:alertController animated:YES completion:nil];

}

谢谢！

Answer 1

按照以下步骤操作，可能会有所帮助：

将delegate和tag设置为UIAlertController文字字段。
现在使用UITextField委托方法shouldChangeCharactersInRange在输入时验证文字或在文本字段结束编辑后使用textFieldDidEndEditing进行检查。检查使用它的标签来区分textFields。

像，

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

if(textField.tag==TxtNameTag){

   //Validate Name textField
}
//Same way for other textFields


    return YES; 
}

或使用textFieldDidEndEditing在textField结束编辑时进行验证。

Answer 2

尝试使用textField委托方法shouldChangeCharactersInRange

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {


// here you can get your textfield text and perform an action according to your choice while user is inputting.

    return YES; //this make iOS not to perform any action
}

Answer 3

查看textField delegate方法shouldChangeCharactersInRange。每次按textfield中的任何字符时都会调用它。

Answer 4

您可以实施UITextFieldDelegate：

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string

Doc

Answer 5

使用textfield的标签属性

UITextField *nameField = alertController.textFields[0];
    UITextField *ageField = alertController.textFields[1];
    UITextField *sexField = alertController.textFields[2];
    UITextField *commentField = alertController.textFields[3];


  nameField.tag = 1;
  ageField.tag = 2;

    - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

    // identify with tag

   if(textField.tag == 1)
   {

   }
    else if (textField.tag == 2)
  {

  }
        return YES; 
    }

Answer 6

1.为UITextField设置委托。

2.添加标签。

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Commend" message:nil preferredStyle:UIAlertControllerStyleAlert];

        [alertController addTextFieldWithConfigurationHandler:^(UITextField *textField) {
            textField.placeholder = @"Please input your name:";
            textField.tag=100;
        }];

3。将为每个输入的字符调用以下代表。

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string 
{

    if(textField.tag==100){

       //Validate Name textField
    }
    else if(textField.tag==101){
    //nextfield textFields
    }
        return YES; 
 }

Answer 7

<your text field>.delegate = self
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
   //name text field validation
   if textField == nameField{
        if textField.text.characters.count < 10 {
           return true
        }
   }

   //age text field validation
   if textField == ageField{
        if Int(textField.text) != nil {
           return true
        }
   }

   //sex text field validation
   if textField == sexField{
        if textField.text + replacementString == "male" {
              <he is a man>
        }else if textField.text + replacementString == "female"{
              <she is a woman>
        }

        return true

   }



   return false
}

Answer 8

[textField addTarget：self action：@selector（textDidChanged :) forControlEvents：UIControlEventEditingChanged];

像这样的副本也可以检查

Answer 9

尝试将JSInputField与modalViewController一起使用

JSInputField *inputField = [[JSInputField alloc] initWithFrame:CGRectMake(10, 100, 300, 50)];
[self.view addSubview:inputField];
[inputField setPlaceholder:@"Please input your name"];
[inputField setRoundedCorners:UIRectCornerAllCorners];
[inputField addValidationRule:JSCreateRuleNotNullValue]; //This will validate field for null value. It will show error if field is empty.
[inputField addValidationRule:JSCreateRuleLength(10)];  //This will validate field for string of length equal to or less than 10.


JSInputField *inputField = [[JSInputField alloc] initWithFrame:CGRectMake(10, 100, 300, 50)];
[self.view addSubview:inputField];
[inputField setPlaceholder:@"Please input your age"];
[inputField setRoundedCorners:UIRectCornerAllCorners];
[inputField addValidationRule:JSCreateRuleNotNullValue]; //This will validate field for null value. It will show error if field is empty.
[inputField addValidationRule:JSCreateRuleNumeric(0)];  //This will validate field for numeric values and restrict to enter value upto 0 decimal places.

如何在用户输入时检查textFiled输入字符串

9 个答案: