Question

I have iphone app in which i enter any number value like 10 2 0 1 0.2 etc i want that instead of this if user enter any text it should alert that enter a number.

    UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Value Must Be In Number " delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [alert show];
    [alert release];

Answer 1

try this code:

- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
    if (textField==txtMobileNo) 
    {
        [self validatePhone];
    }else
    {
        [textField resignFirstResponder];

    }
    // called when 'return' key pressed. return NO to ignore.
    return YES;
}

- (BOOL) validatePhone
{
    NSString *phoneRegex = @"^+(?:[0-9] ?){6,14}[0-9]$"; 
    NSPredicate *phoneTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", phoneRegex]; 
    if ([phoneTest evaluateWithObject:txtMobileNo.text] == YES) 
    {
        NSLog(@"proper phone nO ");        
        return YES;   
    }
    else
    {
        UIAlertView *alert=[[UIAlertView alloc] initWithTitle:nil message:@"Please,Enter Your Person proper phone no" delegate:self cancelButtonTitle:@"Dismiss" otherButtonTitles:nil  ];
        [alert show];
        [alert release];
        NSLog(@"phone no. not in proper format");
        return NO;
        [txtMobileNo becomeFirstResponder];

    }  
}

I hope you helpful.