Adding to list C#

Question

Getting errors when I am trying to save my inputs from textboxes to a list. I am using visual studio and a windows form application. What I want to do is to save the inputs from the textboxes to a list and then display the list in other forms. I have created one class with this code:

public class myClass
{
    public List<customer> customerIdInfo= new List<customer>();

    public class customer
    {
        string Id { get; set; }
        int phoneNumber { get; set; }
        string message { get; set; }
    }
}

Then I have this in my form with the textboxes:

private void nextForm_Click(object sender, EventArgs e)
    {
        Form2 Form1= new Form2(); 

        Form1.Show();

        class myClass= new myClass();
        customerIdInfo.Add(new customer{
                Id = txtCustomerId.Text;
                phoneNumber = txtPhonenumber.Text;
                message = txtMessage.Text;
         });

All the code in the form with the textboxes gets error messages anyone knowws how I can solve this problem?

Answer 1

There were quite some errors in your original code. I have fixed them and commented on them, but Stack Overflow requires a certain level of understanding. Try to pick up a good C# book or read MSDN, so you can learn what the expected syntax is and how you can interpret compiler errors. This isn't exactly the last time you'll get them.

class myClass= new myClass();

You can only use class to declare a class. Here you declare a variable, which is done by naming its type or var:

myClass myClass = new myClass();
// Or
var myClass = new myClass();

Then in your object initializer:

new customer 
{
    Id = txtCustomerId.Text;
    phoneNumber = txtPhonenumber.Text;
    message = txtMessage.Text;
}

You use semicolons (;) where commas should be used (,):

new customer 
{
    Id = txtCustomerId.Text,
    phoneNumber = txtPhonenumber.Text,
    message = txtMessage.Text,
}

And you try to assign a string to an int:

phoneNumber = txtPhonenumber.Text

Which you can't do, it needs to be parsed:

phoneNumber = int.Parse(txtPhonenumber.Text)

You will also need to add error checking, because users can type in things that can't be parsed to an integer.

Then you try to access a variable named customerIdInfo in order to Add() a new customer, but that variable doesn't exist:

customerIdInfo.Add(...);

You want the field of the myClass instance:

myClass.customerIdInfo.Add(...);

And consider making it a property and naming things properly.

Answer 2

class is a reserved word in C# used for defining a class, it can't be used to declare a variable. So the line class myClass = new myClass() won't compile, you want

myClass obj = new myClass();

Or if you are using C# 3.0 or later you can use the var keyword i.e.

var obj = new myClass();

With C# you shouldn't use Pascal casing for variables i.e. Form1, use camel casing

Form2 form = new Form2();

Also, customer is a nested class (not sure if that's deliberate) so unless your new customer code is arguably breaking the design here. Sounds like what you really want is something like

myClass obj = new myClass();
obj.AddNew("CustomerId", 01234567, "Some message");

FYI - telephone number as int is not a great idea, means you can't store values like +44 01234 56789 or (0)141 232-4334 etc.