update 2 different label with same output from 2 different forms simultaneously

Question

i have 2 forms they both have label1, form1 and form2 label1 must show the same output, when i click a button on form1 the label1 in form1 will change so as the label1 in form2

Form1

        SqlDataReader reader = cmdnext.ExecuteReader();
        while (reader.Read())
        {
            label1.Text = reader[0].ToString();
            break;

        }
        sqlcon.Close();

        Lobbypage lp = new Lobbypage(label1.Text);

    }

Form2

     public Lobbypage(string labelText)
    {
        InitializeComponent();
        label1.Text = labelText;

    }

skip button

private void button1_Click(object sender, EventArgs e)
    {
        sqlcon.Open();
        SqlCommand cmdcurrent = sqlcon.CreateCommand();
        cmdcurrent.CommandType = CommandType.Text;
        cmdcurrent.Parameters.Add("@Title", SqlDbType.VarChar).Value = title;
        cmdcurrent.CommandText = "update tblQLCashier set status = 'missing' where queID = (select min(queID) from tblQLCashier where status = 'On process' and department = @Title)";
        cmdcurrent.ExecuteNonQuery();

        SqlCommand cmdnext = sqlcon.CreateCommand();
        cmdnext.CommandType = CommandType.Text;
        cmdnext.Parameters.Add("@Title", SqlDbType.VarChar).Value = title;
        cmdnext.CommandText = "update tblQLCashier set status = 'On process' , department = @Title where queID = (select min(queID) from tblQLCashier where status = 'Pending' and department ='')";
        cmdnext.ExecuteNonQuery();
        sqlcon.Close();

        sqlcon.Open();
        cmdnext.CommandText = "select queID from tblQLCashier where queID = (select min(queID) from tblQLCashier where department in ('', @Title) and status in ('Pending', 'On process'))";
        SqlDataReader reader = cmdnext.ExecuteReader();
        while (reader.Read())
        {
            label1.Text = reader[0].ToString();
            break;

        }
        sqlcon.Close();

        Lobbypage lp = new Lobbypage(label1);

    }

both label1 in form1 and form2 should simultaneously update and have the same output

enter image description here

Possible duplicate of [How to share data between forms?](https://stackoverflow.com/questions/3800603/how-to-share-data-between-forms) — Nirosh Sns, Apr 05 '19 at 05:12
What do you do with the newly created `Lobbypage` (variable `lp`) ? Is it discarded ? — Spotted, Apr 05 '19 at 07:08

score 1 · Answer 1 · answered Apr 05 '19 at 05:35

1

In Form2

public Lobbypage(Label label)
{
    InitializeComponent();
    label1 = label;
}

In Form1

Lobbypage lp = new Lobbypage(label1);

So what's going on ? When giving label1 in Lobbypage's constructor, it creates a new variable (label) which is a copy of label1. The "trick" is that label1 is in fact a reference thus the copy will also point to the same label object.

answered Apr 05 '19 at 05:35

Spotted

4,021
17
33

my prob here is that when i click the skip button the label here in the form1 will change number but in the other form its still the same its still 9 i need to close the form2 and open it again for it to update – vantes leo Apr 05 '19 at 05:40
@vantesleo Did you try my approach ? – Spotted Apr 05 '19 at 05:42
yes, sir still not working only the label in form1 incremented and form2 is still 9 – vantes leo Apr 05 '19 at 05:46
@vantesleo Can you post the event handler called when Skip button is pressed ? – Spotted Apr 05 '19 at 05:50
sorry im new with programming are you asking the skip button code? i already edited my post and add the skip code. ty – vantes leo Apr 05 '19 at 06:05

score 1 · Answer 2 · answered Apr 05 '19 at 08:23

1

you can create one static string property and assign it to both labels.

answered Apr 05 '19 at 08:23

Sumitk

55
10

VValter Bach · Answer 3 · 2019-04-05T07:01:44.297

Why dont u make a public label this is the code that works for me:

namespace WindowsFormsApp1
{
public partial class Form2 : Form
{
    static public Label label2 = new Label();

    public Form2()
    {
        InitializeComponent();
    }

    private void Form2_Load(object sender, EventArgs e)
    {
        label2.Location = new Point(20, 20);
        Controls.Add(label2);
        label2.Text = "mama";
    }
}
}

the other Form

namespace WindowsFormsApp1
{
public partial class Form1 : Form
{

    public Form1()
    {

        Form2 hi = new Form2();
        hi.Show();
        InitializeComponent();
    }

    private void button1_Click_1(object sender, EventArgs e)
    {
        Form2.label2.Text = "Mathman";

    }
}
}

Be sure to add the functions to the handler. that means not just copy paste it in. Dubble click on the form to add the loadfunction automatically after Click before Click

update 2 different label with same output from 2 different forms simultaneously

3 Answers3