One minor question about changing text!

Quang Dinh Luong

11y941C# Corner

You can see that I try to chang my button2 from Form1 when Form2 close, but it doesn't work

Is there a way to do it?

Not the get, set method on Google

Thanks,

6 Replies

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

Sujeet Suman11y ago
Accepted answer
Quang please once try below code:

Step-(01.) On Child Form:-
public event EventHandler OnChildTextChanged;
private void Form2_FormClosing(object sender, FormClosingEventArgs e)
{
   Form1.count = 0;
   if (OnChildTextChanged != null)
         OnChildTextChanged("TextChanged", null);
}

Step-(02.) On Parent Form:-
public static int count = 0;
private void button1_Click(object sender, EventArgs e)
{
   Form2 frm = new Form2();
   if (count < 1)
   {
      frm.Show();
      count++;
   }
   frm.OnChildTextChanged += new EventHandler(child_OnChildTextChanged);
}

void child_OnChildTextChanged(object sender, EventArgs e)
{
   button1.Text = (string)sender;
}

If this is helpful then please accept my Answer.
Sujeet Suman11y ago
Thanks to Quang & Priyaranjan for your appreciation.
Priyaranjan K S11y ago
Great work Sujeet :)

Cheers Quang ! Keep learning !

Thanks,
Priyan
Quang Dinh Luong11y ago
Thanks all :) It works great now!
And more things to learn :))

P/s: Although both Priya and Sujeet's answers work great, I prefer Sujeet's answer.
Why? You can see it yourselves :) (Maybe because he went through my code)
Priyaranjan K S11y ago
Hi ,
There are two ways we can achieve this :
- Get/Set method where we will expose the buttons properties (Since you said you are not looking for that I am skipping that)
- Delegates & EventHandler(This is a very interesting and important topic) - Which i will deal with below :

Place the below code in Form 1:

private void Form1_Load(object sender, EventArgs e)
{
Form2 form2 = new Form2();
form2.evtFrm += new ShowFrm(form2_evtFrm); //Register the event handler
form2.Owner = (Form)this;
form2.Show();
}
void form2_evtFrm(string assign)
{
button1.Text = assign;
}

Place the below code in Form 2 :

namespace WindowsFormsApplication2
{
public delegate void ShowFrm(string assign); //The delegate defines the parameters sent to the event handlers
public partial class Form2 : Form
{
public event ShowFrm evtFrm;
public Form2()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{

if (evtFrm != null)
{
evtFrm("New Button Text");
}
}
}
}

This way we are registering the eventhandler in Form 1 and using delegates in Form2 we are defining the parameter to ne sent to the event handler which is the new button text .

Thanks,
Priyan

If you found this useful Please mark this as Answer
Afzaal Ahmad Zeeshan11y ago
Why "it doesn't work"? Any error that you get?

A simple guess is that it doesn't work, because you are creating a new instance of that form. To see the changes, (for whether that works or not) consider rendering the form.

Like this,
```
Form1 formOne = new Form1();
formOne.button2.Text = "Prime Checker!";
Application.Run(formOne);
```
This would now, run the form (make sure the threads and other stuff doesn't cause a trouble) and will have that text. The problem is that you are not changing the text of currently active form. To receive the update on your current form, consider passing that form (or using that form as a parameter) in this form and then alter the objects in it.