Accessing controls on a new form

Question

Hey!

I have 2 forms in my project, form1 and form2. When I click in a button in form1 I run this code:

Form tempform = new Form2();
tempform.Show();

In my code for Form2 I have a label which I now need to change the text. How can I access the label?

I tried:

tempform.label1.value = "new text"

And that didn't work, I even tried to access using the Controls collection but I think I messed that up. Is there any way I can access the label? OR is there any way I can pass a value to that new form and then have that form alter the label text.

Thanks

Answer 1

Controls have protected access by default. You can change that to public, or you can add a method/property to your form2 class to set the label and call that (latter method is generally preferred to preserve encapsulation and because the designer may want to overwrite your public change.).

Answer 2

If the label value should only be set once, when the form is created, then use a constructor for Form2 like this:

public Form2(string labelValue)
{
  _labelValue = labelValue;
}

and then call that constructor when you create the form.

Alternatively, if the label changes over the lifetime of the form, make a public property:

public string LabelValue
{
  get { return label1.Text; }
  set { label1.Text = value; }
}

Also I would recommend naming the parameters and/or properties to reflect the meaning of the value, for example "titleText" instead of "labelValue". That way Form2 can decide how it wants to display the information (in the title bar, a label, a textbox, etc), and Form1 doesn't have to worry about that.

Edit: Consume the LabelValue property like this:

Form2 newForm = new Form2(); // Assign object to a Form2 instead of Form
newForm.LabelValue = "new text";
newForm.Show();