passing values between two form by using property or delegate?

[vanc]

I read many articles about this problem, but I found out that to pass values between one created form and one is not yet is created is fairly simple, it can be done by assign value to public variable or property in the form will be created.
eg:
form1 f1 = new form1;
f1.var1 = "abc";

form2 f2 = new form2;
f2.var2 = f1.var2;
f2.Show();

But then it's hard to pass a value from the second form back to the form that created it. I don't want to use static variable in the first form to be assigned by the second form. Since the property or delegate which is declared as Public in the first form will never be seen by the second form.

So how can we actually pass the values between two activated forms not by
using static variables?

Cheers.

[vanc]

I found a way to do this by using Delegate together with Event, it fairly simple and very impressive.
Say there are ReceiveForm and SendForm, ReceiveForm will instantiate SendForm and SendForm will talk with ReceiveForm by clicking event at button called btSend, whenever btSend in SendForm is clicked, it will update data in ReceiveForm.
----ReceiveForm----
SendForm f = new SendForm();
//add event to the local method to set data when SecondForm fires this event
f.DataUpdated += new SendForm.DataUpdateHandler(GetData);
f.Show();

//The CustomArgs class will be built to store data later
private void GetData(object sender, CustomArgs e)
{
ReceiveFormData = e.SendFormData;
}

-------SendForm-------
public delegate void DataUpdateHandler(object sender, CustomArgs e);
public event DataUpdataHandler DataUpdated;
//DataUpdateHandler is delegate's name, and DataUpdated is event's name

private void btSend_Click(object sender, SystemEventArgs e)
{
CustomArgs args = new CustomArgs(SendFormData); //store data here
//raise event
DataUpdated(this,args);
}

---------CustomArgs class here---------
public class CustomArgs
{
private string data;
public CustomArg(string input)
{
data = input;
}
//create property to send data back
public string SendFormData
{
get { return data; }
}
}

By this way 2 forms can talk together without creating any new form instances.

[avkdsiva]

But, the first line of your code....

----ReceiveForm----
SendForm f = new SendForm();

Is this not creating an instance of SendForm in the ReceiveForm??

[Snehal Rathod]

Hey hi friend,
I read ur problem. Do u wan to pass the values from one form to another. Is'nt it? Why don't u use Session variable for this purpose. B'coz I m also developing a website. In it I have done the same. Once the value is added in session variable it can be accessec on any page. U can pik it's syntax from help. If ur problem is something else , Plz convey.

Bye take care

[vanc]

the first line of code is to create SecondForm, it has to be done somewhere right! From then on, these two forms can communicate for good.
The point is most of thing I read from forums is just create new form and set value thru property, or thru constructor, not about keeping many forms alive and talking together.

About session variable, I'm working in C# so I don't really know much about this.

[Teenzonez]

If you wanted to pass a value from one form to another using a button:-
There are two forms...Form1 and Form2

Form1 {TextBox/Label & Button} Form2 {Label & TextBox}

In Form1 Button_Click eventhandler, create an instance of Form2
form2.visible = true;
Then fom2.TextBox1.Text = this.txtFrm1.Text;
This will do.. and if you wanna pass something back to form1 do the same in form1..

Regards,
TeenzoneZ