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Hi every
i have two forms in form A i have a button with textbox which open another form with grid view where i add some values and get sum of these values in textbox i need to back textbox sum in form B to textbox In form A ?? how it can be done ? i use c# .
i try apiece of code but i receive this value in form A

What I have tried:

this.ReturnValue1 = txttotal.Text;
// this.ReturnValue2 = DateTime.Now.ToString(); //example
this.DialogResult = DialogResult.OK;
Updated 31-Jan-23 1:42am

Yes - there are a couple of ways, depending on when you want it passed back.
If you use ShowDialog to display the second form, then add a property to the form and read it back after the form has closed.
If you want to update the "main" form without closing the child, use an event: Transferring information between two forms, Part 2: Child to Parent[^]
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MR.alaa 27-Sep-16 6:04am    
it doesn't work with me !! because i have data which i pass it to form 2 and i need to receive a new different data superpose it need in event form close and then pass the values to the first form i declare public variable but how can refresh the form on the child close with the new data ??
OriginalGriff 27-Sep-16 6:16am    
Don't declare public variables! Bad idea...
How are you showing the new form? Are you calling Show or ShowDialog?
try this, refer in line comments

public partial class Form2 : Form
      public string SumValue { get; set; } // create a property in form 2
      private void textBox1_TextChanged(object sender, EventArgs e) // use TextChanged event from properties window
          SumValue = textBox1.Text;


public partial class Form1 : Form
       private void button1_Click(object sender, EventArgs e)
           Form2 objForm2 = new Form2();
           this.textBox1.Text = objForm2.SumValue; // read the value from form2

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MR.alaa 27-Sep-16 6:17am    
in form 1 which button click nothing to click it should receive sumvalue of form2 on form2 closing or as form 1 refresh
Karthik_Mahalingam 27-Sep-16 6:38am    
ok wait, i willupdate the solution.
MR.alaa 27-Sep-16 6:44am    
Karthik_Mahalingam 27-Sep-16 6:57am    
try this

private void Form2_FormClosing(object sender, FormClosingEventArgs e)

foreach (Form f in Application.OpenForms)
if (f.Name == "Form1")
(f as Form1).textBox1.Text = this.textBox1.Text;


note: make the textbox in form1 as public modifier
MR.alaa 27-Sep-16 7:33am    
Thanks worked successfully
in each text change the form opens multiple times. how to avoid this?
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Richard Deeming 31-Jan-23 8:17am    
Your question is not a "solution" to someone else's question.

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