c# - winform - passing variables between forms

Memento

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?

4 Replies

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Vulpes14y ago
Accepted 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;
Memento14y ago
Hi,
I just replaced:
f1.Controls["Label1"].Text = abc;
with:
f1.Label1.Text = abc;
-it works.

ThankYou!!!
Memento14y ago
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.
Vulpes14y ago
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;