CODEWITHSUNDEEP
c#winformslistbox
Danny Watson
Danny Watson

Reputation: 165

How to insert data from List into ListBox?

I have created a List called employees and I want to input all of the information from that List into a list box on the form.

I cannot believe I have forgotten this I have had a look around and I cannot find any concise information, I have a study book, but they use a TextBox instead of a ListBox and they only work with arrays and simple data types. 

List<Employee> employees = new List<Employee>();

This is the list, it contains employees

Employee employee1 = new Employee(1111, "Name", "Skill Set");

I have created an instance of List

Then I add it to the list box on the form

lstFree.Items.Add(employees);

Yet it only appears as 'collection'

What am I doing wrong?

Upvotes: 1

Views: 5151

Answers (3)

Grant Winney
Grant Winney

Reputation: 66501

The Add method expects a single instance of your class. When you pass a collection to it, it calls ToString() and you end up seeing the full class name of the collection. Not what you want.

Instead, you could use a loop:

foreach (var emp in employees)
    lstFree.Items.Add(emp);

Or just assign it to DataSource:

listBox1.DataSource = employees;

You'll also want to tell it which property to display to the user (and optionally, which property to use as the underlying value):

listBox1.DisplayMember = "Name";
listBox1.ValueMember = "EmpId";   // guessing what your class properties might be called

Upvotes: 4

Anton&#237;n Lejsek
Anton&#237;n Lejsek

Reputation: 6103

Consider using AddRange.

object[] arr = Enumerable.Range(1, 10000).Select(i=>(object)i).ToArray();

Compare time of this

// 1,29s
foreach (int i in arr)
{
    listBox1.Items.Add(i);
}

to this 

// 0,12s
listBox1.Items.AddRange(arr);

Upvotes: 2

Marcin Zdunek
Marcin Zdunek

Reputation: 1011

List<Employee> employees = new List<Employee>();
Employee employee1 = new Employee(1111, "Name", "Skill Set");
Employee employee2 = new Employee(2222, "Name", "Skill Set");
employees.Add(employee1);
employees.Add(employee2);

foreach(var empl in employees)
{
    listBox1.Items.Add(empl.ToString());
}

In Employee class:

public override string ToString()
{
    return ""; // return what you need
}

Upvotes: 3

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