How to I pass the database file name through one form to another

Question

In my windows application I am using MS access database. In mainForm (Contain menu), where user will select (open) data file through Dialogbox. And he will be able to select a menu to access the other forms.

Here I need to store the datafile name in a variable and use the same datafile name in the connection string to get the data from the selected data file.

How can I pass the selected database file name through one form to another.

In form 1, I declare a variable;

public string dtFile;

I stored the file path in the dtfile variable at Open file Dialog.

dtFile = openFileDialog.FileName;

In the form2 I have written

Form1 frm = new Form1; string strDataFile = frm.dtFile;

Here I am getting null value. How to get the data of dtFile variable of Form 1 in From 2

Answer 1

you can do like this, you will be able to access all the things of Form1 on the other form:

private void button1_Click(object sender, EventArgs e)
    {
    Form1 newform = new Form1();
            newform = this;
            this.Hide();
            MySecform = new Form2(ref newform);
            MySecform.Show();
    }

The other way around is using custom Events:

see details here:

http://www.codeproject.com/Articles/17371/Passing-Data-between-Windows-Forms

you can also make a Static Class if you want the value to be accessible in all forms of your application:

static class Global
{
    private static string _globalVar = "";

    public static string GlobalVar
    {
        get { return _globalVar; }
        set { _globalVar = value; }
    }
}

Answer 2

In First form declare dtFileName as static variable.

 public static string dtFileName;

On selecting file name through dialogbox

dtFileName = openFileDialog.FileName;

And in form2

public partial class Form2 : Form
    {        
        string strDataFilePath = "";

        public Form2 ()
        {
            InitializeComponent();            
            strDataFilePath = Form1.dtFileName.ToString();
        }
    }