C# Discussion Boards - CodeProject

Re: How to access a control on a Form from other Forms without creating an instance of it?

5-Sep-09 9:08

Hey budyies i wanted to access(insert datas in to) a listview item in one of my other forms ........... while the form that contains the listview is running(lets say it FormListView) and the other form is still running @ the same time(lets say FormSender) ......... I wanted to read a data from the listview in the FormSender and send it back to the FormListView ......... even if I make the Modifier Property of the FormListView as Public I cant call it like this from the FormSender

FormListView.listView1.Items.add("xxxx");

but I can access variables that are declared like this ....

Public static string x;

I can access by writing this code with out creating its instance

FormListView.x="xxxxx";

Please help me.

Thank you

DaveyM695-Sep-09 10:14

DaveyM69

5-Sep-09 10:14

I'd create public or internal Add and Read methods on the FormListView (keeping the ListView's access modifier private).
When you create the instance, hold it in a field

public class FormSender
{
    FormListView formListView;

    // ...

    void MethodThatInstanciatesFormListView()
    {
        formListView = new FormListView();
        formListView.Show();
    }

    void ReadData()
    {
        List<Data> data = formListView.Read();
    }
    void AddData(Data data)
    {
        formListView.Add(data);
    }
}

public class FormListView
{
    public List<Data> Read()
    {
        // ...
    }
    public void Add(Data data)
    {
        // ...
    }
}

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)
Why are you using VB6? Do you hate yourself? (Christian Graus)

Re: How to access a control on a Form from other Forms without creating an instance of it?

CoderForEver5-Sep-09 20:44

Re: How to access a control on a Form from other Forms without creating an instance of it?

5-Sep-09 20:44

DaveyM69 wrote:
List data

what does the "List" and "<Data>" refers to....sry I have no idea abt that ... but I will try it .... and 1 more question.

DaveyM69 wrote:
void AddData(Data data)

what data type is this "Data"

Thank you for ur help.

DaveyM695-Sep-09 23:24

DaveyM69

5-Sep-09 23:24

matiIsGreat wrote:
what data type is this "Data"

Change it for whatever class/struct you are using to hold the data you are wanting to pass to formListView

matiIsGreat wrote:
List

You don't have to use a List<T>, but it's a useful way of having a collection of whatever T is in one object. Clickety[^]

Re: How to access a control on a Form from other Forms without creating an instance of it?

Christian Graus5-Sep-09 10:43

Christian Graus

5-Sep-09 10:43

The only sane way to do this, is to set up delegates so that the code that decides the form needs filling, can call a method in the form to fill it with data.

Christian Graus

Driven to the arms of OSX by Vista.

Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.

Re: How to access a control on a Form from other Forms without creating an instance of it?

CoderForEver5-Sep-09 20:33

Re: How to access a control on a Form from other Forms without creating an instance of it?

5-Sep-09 20:33

Even if i worked simple applications on c# 4 a year .... i didnt use delegates .... so i have no idea abt them ......... so can u show me sth hw to work on ma problem .

Thank you

Luc Pattyn5-Sep-09 11:05

Luc Pattyn

5-Sep-09 11:05

two remarks on top of the fine answers you've got:

1. forms don't "run", they exist, and they may or may not be visible, have focus, etc.

2. "static" seldom is the solution; it is useful to create variables that exist only once per class instead of once per instance, e.g. when a class wants to count how many instances got created. Nothing else.

Smile | :)

Luc Pattyn

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Have a look at my entry for the lean-and-mean competition; please provide comments, feedback, discussion, and don’t forget to vote for it! Thank you.

Problem sending an emai [modified]

Jassim Rahma5-Sep-09 8:30

Jassim Rahma

5-Sep-09 8:30

I am using the followijg code to send email trough my Gmail account but I am having two problems, first it's taking long time to send the email and second the From is showing as my Gmail account not the user email specefied in the txtEmail

private void btnSend_Click(object sender, EventArgs e)
{
    this.Cursor = Cursors.WaitCursor;

    txtEmail.Enabled = false;
    txtMessage.Enabled = false;
    btnSend.Enabled = false;
    btnClose.Enabled = false;

    if (radioSuggestion.Checked == true)
        email_subject = "Suggestion from (My System) user";
    else if (radioBug.Checked == true)
        email_subject = "Bug Reported by (My System) user";
    else
        email_subject = "Email from (My System) user";

    if (SendMail("myGmailAccount@gmail.com", "xxxxxxxxx", txtEmail.Text, "myHotMailAccount@hotmail.com", email_subject, txtMessage.Text))
    {
        MessageBox.Show("Message Sent.", "Email", MessageBoxButtons.OK, MessageBoxIcon.Information);
        this.Cursor = Cursors.Default;
        this.Close();
    }
    else
    {
        MessageBox.Show("unable to send your email!!", "Email", MessageBoxButtons.OK, MessageBoxIcon.Error);
        txtEmail.Enabled = true;
        txtMessage.Enabled = true;
        btnSend.Enabled = true;
        btnClose.Enabled = true;
        this.Cursor = Cursors.Default;
        return;
    }
}



public static bool SendMail(string gMailAccount, string password, string from, string to, string subject, string message)
{
    try
    {
        NetworkCredential loginInfo = new NetworkCredential(gMailAccount, password);
        MailMessage msg = new MailMessage();
        msg.From = new MailAddress(from);
        msg.To.Add(new MailAddress(to));
        msg.Subject = subject;
        msg.Body = message;
        msg.IsBodyHtml = true;
        SmtpClient client = new SmtpClient("smtp.gmail.com");
        client.EnableSsl = true;
        client.UseDefaultCredentials = false;
        client.Credentials = loginInfo;
        client.Send(msg);

        return true;
    }
    catch (Exception)
    {
        return false;
    }

}

modified on Saturday, September 5, 2009 2:56 PM

CoderForEver5-Sep-09 8:52

5-Sep-09 8:52

Hey budy .... even if i had no answer 4 u please make ur code more stylish so that others read it and give an answer ............ use code block

Jassim Rahma5-Sep-09 8:58

Jassim Rahma

5-Sep-09 8:58

noted..

waiting for a reply..

CoderForEver5-Sep-09 9:21

5-Sep-09 9:21

hope u r now getting ideas..... c z difference

Good Luck

Richard MacCutchan5-Sep-09 11:02

Richard MacCutchan

5-Sep-09 11:02

matiIsGreat wrote:
hope u r now getting ideas..... c z difference

Please use proper words in your answers. "u r" means nothing, similarly "c z" could be written by a monkey. If you expect the questioners to put their questions in clear English then the least you can do is answer in a similar vein! Try and act as if you are at least aspiring to professionalism.

0x3c05-Sep-09 9:03

0x3c0

5-Sep-09 9:03

Thanks for reformatting your code. The change in the From field is probably because Google's SMTP server is changing the email headers mid-stream. The delay could be almost anywhere. My guess is that you're trying to send a very large email. The SmtpClient.SendAsync might help you with that problem.

OSDev

Jassim Rahma5-Sep-09 9:06

Jassim Rahma

5-Sep-09 9:06

I am just sending :

this is a test email

Abhishek Sur5-Sep-09 11:17

Abhishek Sur

5-Sep-09 11:17

you must specify the Port that send mails

client.Port = 587

You can also read my article about this. How to Send Mails from your GMAIL Account through VB.NET or C#. Windows Programming, with a Bit of Customization[^]

Rose | [Rose]

Abhishek Sur

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(X^2)(4sinY)

Farhad Eft5-Sep-09 8:06

Farhad Eft

5-Sep-09 8:06

Hi
I was wondering how I can implement this function in c #
There are 2 variables, x & y:

(X^2)(4sinY)

0x3c05-Sep-09 8:36

0x3c0

5-Sep-09 8:36

You can do it in the normal way:

double Z = (X * X) * (4 * Math.Sin(Y));

OSDev

Henry Minute5-Sep-09 8:40

Henry Minute

5-Sep-09 8:40

FYI: The '^' operator is Bitwise XOR in C#.

0x3c05-Sep-09 8:46

0x3c0

5-Sep-09 8:46

Further FYI: The Math.Pow operation raises something to a power.

OSDev

Henry Minute5-Sep-09 9:47

Henry Minute

5-Sep-09 9:47

Extended Further FYI: The Math.Ker method reinforces the Math.Pow method.

Luc Pattyn5-Sep-09 11:10

Luc Pattyn

5-Sep-09 11:10

FYI^3
... by using logarithmic and exponential functions, making it rather slow and slightly inaccurate for a simple square or cube or square root.

Smile | :)

Luc Pattyn

Have a look at my entry for the lean-and-mean competition; please provide comments, feedback, discussion, and don’t forget to vote for it! Thank you.