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C# issue: How do I manipulate a Textbox on one form from another form?

Answer 1

A:

You can make the TextBox public first of. Second make a static form(name of your form) variable and put the form there each time its loaded... This is not a good solution in my eyes but without knowing more about your design its the best i can come up with...

Petoj 2009-02-04 08:25:31

Can't make a form static and modify the contents of this.errortext.text because ill get the error: An object reference is required for the non-static field, method, or property.

OneShot 2009-02-04 09:54:32

Thats not what i meant.. what i meant was make a static variable that points to the form you want to manipulate..

Petoj 2009-02-04 10:26:50

How do I do that?

OneShot 2009-02-04 13:23:33

Answer 2

+1 A:

Yes! have a function made public that can receive this text:

pseudo: public void updateTextBox(string new_text)

and have the function update the textbox from there.

don't mix UI with logic.

Ric Tokyo 2009-02-04 08:25:36

You are right, that should work right? Nope. Because in order for me to see the function I have to set the function to static...which brings me to the issue in the first place. If I set it to static I get the error: An object reference is required for the non-static field, method, or property.

OneShot 2009-02-04 09:52:00

@OneShot: Use non static function as delegate to be able to call non-static method

Ric Tokyo 2009-02-04 10:47:47

How do I do that?

OneShot 2009-02-04 13:24:56

@OneShot http://msdn.microsoft.com/en-us/library/aa288459(VS.71).aspx

Ric Tokyo 2009-02-04 13:50:46

Unbelievable...I figured it out because of you. Thank you.

OneShot 2009-02-04 14:33:36

@OneShot happy to help! Good job mate :)

Ric Tokyo 2009-02-04 14:43:07

Answer 3

+6 A:

I would just pass the message as a constructor parameter.

MyMessageBox messageBox = new MyMessageBox("My error message");
messageBox.Show();

Gerrie Schenck 2009-02-04 08:25:45

No I don't want that, I have created my own form. I don't want a messagebox I want my Form to appear with the specific messages that i've set from another form.

OneShot 2009-02-04 09:55:12

Answer 4

A:

Allowing public access to an object contained in your class may be a design. How about writing a property in the error window class called ErrorText and inside that property set the ErrorMessage.Text to the passed string? Or am I missing something?

Frederick 2009-02-04 08:27:24

I tried that, but I can't see ErrorMessage.Text...its still private in the Windows Form Designer generated code

OneShot 2009-02-04 09:43:48

Answer 5

A:

If you really want to go with accessing the controls directly:

  public Form2(Form1 form1)
        {
            InitializeComponent();

            Owner = form1;
            _form1 = form1;
        }

now you can access the controls on form1 this way:

_form1.theForm1ControlName

Ric Tokyo 2009-02-04 08:28:14

I like your idea. I am not sure how to get that to work though.Can you revise that with the current variables...I need formSettings to display formErrorWindow. That would be perfect if I could give the form that is displaying the message ownership over the form.

OneShot 2009-02-04 10:10:09

either can get ownership over the other...

Ric Tokyo 2009-02-04 10:51:12

I noticed you have the method inside the class of which you are generating an object from.. are you sure you don't want to put this method in another class?

Ric Tokyo 2009-02-04 10:51:53

I don't know any other way to accomplish what I need? =/

OneShot 2009-02-04 13:24:25

make two forms, a big one formsettings and a small one formerror, you have there is two instance of the same form.. make two different forms instead..

Ric Tokyo 2009-02-04 13:51:55

Answer 6

A:

You could create a method in the Error window's class which could be something like:

public void SetErrorText(string errorText)
{
   this.ErrorMessage.Text = errorText; // assuming the TextBox' ID is ErrorMessage.
}

2009-02-04 08:31:02

The only way I can see that function outside of the specific form (aka make it "Global") is if I set it to static. If I make the class static I can't use "this.ErrorMessage.Text" because Ill get the error: An object reference is required for the non-static field, method, or property.

OneShot 2009-02-04 09:53:47

Answer 7

A:

Sounds like you're on the right track by adding the public function you did, but you shouldn't have to make it static. As a general rule, if you have to go into the Designer Generated Code, something isn't right, so let's get out of there - it doesn't mean you can't add code to the form, obviously, but don't do it in that section :)

The error you're getting I believe originates from having a non-instantiated object (i.e. creating the error form like:

formErrorWindow myErrorWindow;

as opposed to instantiating it / creating an instance of it like so:

formErrorWindow myErrorWindow = new formErrorWindow();

You've made the function static, so you can see it from anywhere, however that function can't actually do anything because the form that it runs on doesn't exist yet until you use " = new formErrorWindow();".

So if I'm in a form called "MainForm" and I want to show an error, using the name of the function you provided it would be done like this:

formErrorWindow myErrorWindow = new formErrorWindow();
myErrorWindow.showError("Title", "User Message Here", "Error Message Here");
myErrorWindow.ShowDialog();

The key is to make sure nothing is static and then make sure you're initializing the formErrorWindow with = new formErrorWindow();

routeNpingme 2009-02-08 01:53:57

Answer 8

A:

solved my problem... thanx.. i jz wnt to get item of list box control from one form to another.. thnx..

2009-04-06 12:21:46

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C# issue: How do I manipulate a Textbox on one form from another form?

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