Question

I’m not able to pass data of multiple text boxes from Form1 to Form2 through a button click. I have tried the following way, but it is not working.

Did I do it wrong? And if so, how can I do it?

Form1 Code:

public partial class Form1: Form {
    Form2 frm2;

    public Form1() {
        InitializeComponent();
    }

    private void btnInvoice_Click_1(object sender, EventArgs e) {
        this.Hide();

        if(frm2==null)
            frm2=new Form2();

        frm2.ValueFromForm1(txtFirstName.Text);
        frm2.ValueFromForm1(txtLastName.Text);
        frm2.ValueFromForm1(txtCellNo.Text);
        frm2.ValueFromForm1(txtDate.Text);
        frm2.ValueFromForm1(txtDueDate.Text);

        frm2.Show();
    }
}

Form2 Code:

public partial class Form2: Form {
    public Form2() {
        InitializeComponent();
    }

    public void ValueFromForm1(string value) {
        txtFirstName.Text=value;
        txtLastName.Text=value;
        txtCellNo.Text=value;
        txtMaskDueDate.Text=value;
        txtMaskDate.Text=value;
    }
}

Answer 1

You are assigning same value to all textboxes. And result will be last value you are assigning (which is txtDueDate text). Create different methods to assign values for each of textboxes, or pass values as array, or as a custom object:

public class Invoice
{
   public string FirstName { get; set; }
   public string LastName { get; set; }
   public string CellNo { get; set; }
   // etc
}

On Form1

private void btnInvoice_Click_1(object sender, EventArgs e)
{
    this.Hide();
    if (frm2 == null)
        frm2 = new Form2();

    Invoice invoice = new Invoice();
    invoice.FirstName = txtFirstName.Text;
    invoice.LastName = txtLastName.Text;
    invoice.CellNo = txtCellNo.Text;
    // etc
    frm2.Invoice = invoice;
    frm2.Show();
}

On Form2

public Invoice Invoice
{
   set
   {
        txtFirstName.Text = value.FirstName;
        txtLastName.Text = value.LastName;
        txtCellNo.Text = value.CellNo;
        // etc
   }
}