Pass data between forms

Phil Saville

hi there, im having trouble trying to pass strings from my 2nd windows form to my 1st windows forms...

i have two simple forms, the first just has just a button on which opens the 2nd form so the 2 forms are open at the same time. On this 2nd form i then have a text box and another button, the user will enter some text into the textbox and then press the button. Once this button is pressed i would like the text to be passed to the first form. I have tried using the following code...

Form1:

public partial class Form1 : Form
    {
        string text;

        public Form1(string receivedText)
        {
            text = receivedText;
            InitializeComponent();
        }

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

        private void Form1_Load(object sender, EventArgs e)
        {
            if (text == "")
            {
            }
            else
            {
                label1.Text = text;
            }
        }
    }

Form2:

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

        private void button1_Click(object sender, EventArgs e)
        {
            Form1 f = new Form1(textBox1.Text);
            this.Hide();
        }
    }

This does not seem to work though and i get the error..." 'Pass.Form1' does not contain a constructor that takes '0' arguments.

Please help!

6 Replies

Know the answer? Post it — somebody with the same question will find it here.

Sam Hobbs16y ago

One problem is that in Form2 you are creating another instance of Form1 and I doubt that is what you need. You probably need to update the label in the existing instance of Form1. The following code should help; I did not do the code to hide/show Form1 but I assume you can do that.

using System;

using System.Windows.Forms;



namespace _80050

{

	public partial class Form1 : Form

	{

		public Form1()

		{

			InitializeComponent();

		}



		private void button1_Click(object sender, EventArgs e)

		{

			Form2 f = new Form2();

			f.f1 = this;

			f.Show();

		}



		public void SetLabel(String s)

		{

			label1.Text = s;

		}

	}

}

using System;

using System.Windows.Forms;



namespace _80050

{

	public partial class Form2 : Form

	{

		public Form1 f1 = null;



		public Form2()

		{

			InitializeComponent();

		}



		private void button1_Click(object sender, EventArgs e)

		{

			if (f1 != null)

				f1.SetLabel(textBox1.Text);

			Close();

		}

	}

}

kiran kumar16y ago
hello friend,test the code which i am uploading
mark the answer if it helps you
0
Syed Shakeer16y ago
Hi
1)First Create a Static Class and declare a Variable as follows:-
Static Class statclass
{
public string statstring=String.Empty;
}
2)assing the textbox value to statstring in 2Form as Follows:-
private void button1_Click(object sender, EventArgs e)
        {
        statclass.statstring =textbox1.Text;
            Form1 f = new Form1(textBox1.Text);
            f.Show();
        }
3)Dispalying the 2Form text value in Form1 as Follows:-
write the below code in FormLoad
Label1.Text=statclass.statstring ;
0
Raaj Kumar16y ago
Then try adding a default constructor just like this,

public Form1()
        {
           InitializeComponent();
        }

So you will have what you need. Now there wont be any problem.

Regards,
raaj
0
Phil Saville16y ago
but the problem i have is that if i change the program.cs file to Application.Run(new Form2()); then it opens form 2 from the start which isn't what i want... i would like for form 1 to be opened first, then once the button is clicked it opens form 2, and then the user enters some text and presses the button on form 2 which will take the user back to form 1 with the text.

if this makes sense
0
Raaj Kumar16y ago
Hi,

It seems that in Program.cs file the problem happens. Since it would be like

Application.Run(new Form1());

and the actual constructor is
public Form1(string receivedText)
        {
            text = receivedText;
            InitializeComponent();
        }

which expects a parameter. So change the form name to Form2 like this,

Application.Run(new Form2()); (inside Program.cs where this is the entry point of the application)

If needed I can provide you a sample application of what you required.

Regards,
raaj
0