Question about class

Boguda Boguda

12y1.8kVisual Basic .NET

Hi I need some help about C#

I know it is elementary but I don't know how to do that. and also I works without database

I have class User with

string name;

string lastname;

int years;

and then a metod insert ()

{

User us=new User();

name=textbox1.Text;

lastname=textbox2.Text;

years=textbox3.Text;

}

Now for example I need to add(insert) tree(3) users and then write them in listbox, message box or something.

I hope I was clear enough and correctly ask the question

(How to read all instaces of the same class and also I need to sort them by year)

7 Replies

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Vulpes12y ago
The code is working fine for me.

Are you sure that there is something in the texboxes when you click the button?

Also did you remember to add the button_Click event handler via the VS designer rather than manually?
Boguda Boguda12y ago
it does not work for me. It always returns me null. In list box for name and last name I see empty string "" and for years I see "0"
Vulpes12y ago
No, it works for any number of users.

I added two to start with and additional users can then be added by filling in the TextBoxes and pressing the button.

As you said that the users needed to be sorted by 'years', I assumed that you wanted the whole record to be shown in the listbox. By overriding the ToString method in the User class, we can layout exactly how each record should be displayed so that the properties line up.
Boguda Boguda12y ago
public override string ToString() { return String.Format("{0, -10} {1, -10} {2, 3}", Name, LastName, Years); } What is this?
Boguda Boguda12y ago
ok but I don't now how many user I will have it seems that you solution work works only for 2 users
Nitesh Kejriwal12y ago
+1 for Vulpes sir!
Vulpes12y ago
If it's a Windows Forms application, you can do something like this.

You'll need to set the ListBox's Font property to a fixed width font (such as Consolas) so that the properties line up properly.

I've added two User objects to the ListBox in Form1_Load and you can then add a third (or as many others as you like) by filling out the 3 textboxes and then pressing the button to insert them. They will be automatically sorted by 'years':

class User
{
public string Name { get; set; }
public string LastName {get; set;}
public int Years {get; set;}

public User(string name, string lastName, int years)
{
Name = name;
LastName = lastName;
Years = years;
}

public override string ToString()
{
return String.Format("{0, -10} {1, -10} {2, 3}", Name, LastName, Years);
}
}

public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private List users = new List();

private void Form1_Load(object sender, EventArgs e)
{
User user1 = new User("Barack", "Obama", 53);
User user2 = new User("Cameron", "David", 47);
users.Add(user1);
users.Add(user2);
users = users.OrderBy(u => u.Years).ToList();

foreach (User u in users)
{
listBox1.Items.Add(u.ToString());
}
}

private void button1_Click(object sender, EventArgs e)
{
int years;
int.TryParse(textBox3.Text, out years);
User user = new User(textBox1.Text, textBox2.Text, years);
users.Add(user);
users = users.OrderBy(u => u.Years).ToList();

listBox1.Items.Clear();

foreach (User u in users)
{
listBox1.Items.Add(u.ToString());
}

}
}