Fields completion verify

Question

I have a form with some fields on it:

folderNameLabel
folderTitle
folderDescription
folderCategory

Before the user will press OK, I want to check if all that fields are not =="". I wanted to make a function to receive an array as parameter and return a bool value, but I am not sure how to write it...

Answer 1

You could do the following:

private void btnOK_Click(object sender, EventArgs e)
{
    bool fieldsFilled = ValidateStrings(folderNameLabel.Text, 
                                        folderTitle.Text, 
                                        folderDescription.Text, 
                                        folderCategory.Text);
    if (fieldsFilled)
        DialogResult = DialogResult.OK;
    else
    {
        // Report errors
    }
}

private bool ValidateStrings(params string[] items)
{
    bool result = true;
    for (int i = 0; i < items.Length && result; i++)
        result &= !String.IsNullOrWhitespace(items[i]);

    return result;
}

Question: How do you tell the user which field he missed?

In your case, you could show a "You need to fill in all fields" message, but having only one optional field, that doesn't work anymore. This is why usually you don't do something like above.

Answer 2

public bool Validate(List<string> parameters)
{
   foreach(string parameter in parameters)
   {
        if(String.IsNullOrEmpty(parameter))
        {
            return false;
        }
   }
   return true;
}