c# - winform - passing variables between forms

Question

c# - winforms
On Form1 I have a Button and a Label (Label1)
ButtonClick:
Form2 Form2 = new Form2();
Form2.ShowDialog();
On Form2 I have a dgv
Form2.ClosingEvent:
string abc = Form2.dgv.CurrentCell.Value.ToString();
Form1.Label1.Text = abc;
How could I do this?

Vulpes · Answer

If Label1 is public you can simply do: string abc = this.dgv.CurrentCell.Value.ToString(); Form1 f1 = (Form1)this.Owner; f1.Label1.Text = abc; or if you can't change the call to ShowDialog to include the 'this' parameter: string abc = this.dgv.CurrentCell.Value.ToString(); Form1 f1 = (Form1)Application.OpenForms[Form1]; f1.Label1.Text = abc;

Memento · Answer

Hi I just replaced: f1.Controls[Label1].Text = abc; with: f1.Label1.Text = abc; -it works. ThankYou!!!

Memento · Answer

Vulpes I got error: Object reference not set to an instance of an object. Label1 is not direcrtly on Form1 but in a TabControl1 - TabPage1 - GroupBox1 I tried: f1.Controls[TabControl1.TabPage1.GroupBox1.Label1].Text = abc; - the same error. There is no possibility to change Form1 design. TabControl is full docked. I have no room to place Label1 outside of TabControl. Could yo write the solution in that case pls. I cheked: f1.Controls[Label1].Text = abc; MessageBox.Show(abc); -it works. Also modifiers for Label1 are - Public.

Vulpes · Answer

There are many ways but here's one. This assumes that Label1 is placed directly on Form1 rather than in some container such as a panel. Change code on Form1 to this: Form2 Form2 = new Form2(); Form2.ShowDialog( this ); // this makes Form1 Form2's Owner Place this code in Form2's FormClosing eventhandler: string abc = this.dgv.CurrentCell.Value.ToString(); Form1 f1 = (Form1)this.Owner; f1.Controls[Label1].Text = abc;