C# Arraylist into a label

Question

I'm working with C# in a web form. I setup an arraylist. I have a button that add user input in a text box to the arraylist. I'm using the += to print out the arraylist to a label. I'm having trouble just printing out the new entry to the exisiting list. Each time I add, it prints out the whole list again. I understand why it's doing that but just can't wrap my fried brain at the moment how to fix the code so it adds a new entry to the list without repeating the whole list.

protected void Button1_Click(object sender, EventArgs e)
{


    ArrayList itemList = new ArrayList();
    itemList.Add("red");
    itemList.Add("blue");
    itemList.Add("green");
    itemList.Add(TextBox1.Text);

    foreach (object item in itemList)
    {
        Label1.Text += item + "<br />";
    }



}

Community · Accepted Answer · 2017-05-23 12:06:42Z

3

Don't use the obsolete ArrayList class. Use a generic version of it, List<T>.

List<string> itemList = new List<string>();
itemList.Add("red");
itemList.Add("blue");
itemList.Add("green");
itemList.Add(textBox1.Text);

Now you can update your label with a single line...

Label1.Text = string.Join("<br />", itemList);

EDIT

Unfortunately, for this example I have to use an arraylist

You can still do it with one line

Label1.Text = string.Join("<br />", itemList.Cast<string>());

edited May 23, 2017 at 12:06

CommunityBot

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answered Sep 27, 2015 at 14:14

Eser

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2 Comments

Blazto Over a year ago

Unfortunately, for this example I have to use an arraylist.

Blazto Over a year ago

Thank you everyone all the examples work. I having another problem with keeping the previous entry in the arrayList. I think I have to declare a string array and store it in there but not sure, doing the trial and error thing at the moment.

codersl · Accepted Answer · 2015-09-27 13:57:17Z

1

Just add Label1.Text = "" before the for loop.

answered Sep 27, 2015 at 13:57

codersl

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Comments

Jens Kloster · Accepted Answer · 2015-09-27 13:58:15Z

0

Before you start the loop do this:

Label1.Text = string.Empty;

answered Sep 27, 2015 at 13:58

Jens Kloster

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