C# Discussion Boards - CodeProject

Re: What is the differentation between Convert.ToInt32() and (int) Casting

dan!sh 5-Jul-09 2:16

5-Jul-09 2:16

Yes there is. If you box the double value, then Convert would work but casting will not. This happens as (int) directly tries to convert test to int without unboxing.

Re: What is the differentation between Convert.ToInt32() and (int) Casting

OriginalGriff5-Jul-09 2:25

OriginalGriff

5-Jul-09 2:25

Convert.ToInt32 (and related int convertions) convert with banker's rounding whenever the argument is of type Decimal, float, or double. (i.e. if the input is between two integers, it returns the even integer.)

The (int) cast will only truncate - ie throw away the fractional part.

In addition, (int) will only work on numeric types while Convert.ToInt32 is overloaded to work with a wide range of data types.

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What is the diffirentation between Stack and Stack<Person>

dataminers5-Jul-09 1:00

dataminers

5-Jul-09 1:00

Person is my class, it contains just get and set property.

What is the diffirentation between following;

Stack stack = new Stack();
Stack<Person> stack = new Stack<Person>();

Already Stack get object type. Why I use <person>

Thanks...

Re: What is the diffirentation between Stack and Stack<Person> [modified]

Luc Pattyn5-Jul-09 1:10

Luc Pattyn

5-Jul-09 1:10

Hi,

since .NET 2.0 we have "generics", so collections can be typed, making it unnecessary to cast when something is gotten from a collection.

When you used to do int a0=(int)myList[0]; (where myList is an old ArrayList), you now can do int a0=myList[0]; where myList is a List<int>. That is easier, safer and faster.

Smile | :)

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modified on Sunday, July 5, 2009 7:32 AM

Re: What is the diffirentation between Stack and Stack<Person>

dataminers5-Jul-09 1:29

dataminers

5-Jul-09 1:29

Sorry, I cant understand your example, both of theme same. My question related about stack and generic stack.

Best Regards...

Re: What is the diffirentation between Stack and Stack<Person>

Luc Pattyn5-Jul-09 1:33

Luc Pattyn

5-Jul-09 1:33

typo fixed, sorry.

Smile | :)

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Re: What is the diffirentation between Stack and Stack<Person>

OriginalGriff5-Jul-09 1:36

OriginalGriff

5-Jul-09 1:36

To add to what Luc says, it also makes it harder to use the list badly. With the earlier Stack, you could happily say:

Stack li = new Stack();
li.Push(42);
li.Push("Hello");

without complaint.
with the generic lists if you try the same thing:

Stack<int> li = new Stack<int>();
li.Push(42);
li.Push("Hello");

the compiler will complain that you can't add a string to the stack.

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Form.Hide() doesn't work

Javango4-Jul-09 23:11

Javango

4-Jul-09 23:11

Hi, I am writing a background application witch you can drop in the autostart of Windows. The application has to work fully in background and should not show the form at startup.
Question: If I write "this.Hide();" just behind the automatically created codeline "InitializeComponent();" in the main form, but the program anyway shows the form!
It looks, like "Application.Run(new MainForm());" shows the form again, but I can't do anything against!?

MainForm.cs:
    public MainForm() {
      InitializeComponent();
      this.Hide();
    }

program.cs
    static void Main() {
      Application.EnableVisualStyles();
      Application.SetCompatibleTextRenderingDefault(false);
->    Application.Run(new MainForm());      
    }

Thanks for every help.

Re: Form.Hide() doesn't work

Baeltazor4-Jul-09 23:33

Baeltazor

4-Jul-09 23:33

Hi Javango,

I've also had this problem. And have found an alternative way of 'hiding' the form. By using:

this.Visible = false;

And to show the Form again, use:

this.Visible = true;

Hope this helps. Smile | :)

Regards,
Jase.

Re: Form.Hide() doesn't work

Javango4-Jul-09 23:55

Javango

4-Jul-09 23:55

Hi, thanks for your answer. I tried with "this.Visible" but unfortunatly this doesn't helps. As I think, this is exactly the same as you use the method.
Anyway, if the method run() is overwriting the Visible property (as i think) it would be hided and showed again.?

Re: Form.Hide() doesn't work

Baeltazor5-Jul-09 0:24

Baeltazor

5-Jul-09 0:24

Javango wrote:
run() is overwriting the Visible property (as i think)

Okay, so where did you paste the

this.Visible = false;

code? It should be placed inside the Form1_Load event if you want to hide the form at startup, like so:

private void Form1_Load(object sender, EventArgs e)
        {
		this.Visible = false;

		/* The above code will
		hide the form when the application starts up */
	}

If that's how you've used the code and it doesn't work then maybe you could try replacing:

this.Visible = false;

with this:

Form.ActiveForm.Visible = false;

OR;

If you believe that the run() method is overwriting the Visible property then maybe you could try hiding the Form once it's been shown. You can do this by creating a Form1_Shown event handler and using the same code provided above.

Hope this helps.

Jase.

Re: Form.Hide() doesn't work

Javango5-Jul-09 1:01

Javango

5-Jul-09 1:01

Hi, ok the setting in Form1_Load() didn't work too, but i solved it now with the Shown event (although I don't like workarounds like this):

private void MainForm_Shown(object sender, EventArgs e) {
  if (!started) this.Hide();
  started = true;
}

Thank's for your answers.

Re: Form.Hide() doesn't work

rahul.sree6-Jul-09 20:40

rahul.sree

6-Jul-09 20:40

hi
to hide the form just copy the following code.it should work... Smile | :)

<br />
this.Visible = false;<br />

then the active form wiil be hidden.
if u want to show another form then use

<br />
Form2.show();<br />

Re: Form.Hide() doesn't work

Mycroft Holmes4-Jul-09 23:43

Mycroft Holmes

4-Jul-09 23:43

Javango wrote:
I am writing a background application witch you can drop in the autostart of Windows

This is called a service application and does not have a UI. You are using the wrong tool for the job, look into windows services.

Never underestimate the power of human stupidity
RAH

Re: Form.Hide() doesn't work

Javango4-Jul-09 23:59

Javango

4-Jul-09 23:59

Hi, thanks for your answer.
I use the Form for user settings and options witch is displayed when the user doubleclicks on an Icon in the system tray.

Re: Form.Hide() doesn't work

Luc Pattyn5-Jul-09 1:07

Luc Pattyn

5-Jul-09 1:07

Hi,

this is all wrong.
If you don't want a Form, then don't define a form class, and don't instantiate one.

If you do need a message pump, you can do Application.Run() without a parameter. And if you don't, you can do all in the static Main() method.

Smile | :)

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Drawing ellipse in C# .

shameerpv4-Jul-09 22:16

shameerpv

4-Jul-09 22:16

How can i draw an ellipse on an image in C#?? Currently I m drawing it on the picture box, but the problem was that I m not able to remove the ellipse for another images..

Re: Drawing ellipse in C# .

molesworth4-Jul-09 22:35

molesworth

4-Jul-09 22:35

If you're drawing an ellipse, presumably you have access to the graphics object - which has a handy "Clear" method...

There are three kinds of people in the world - those who can count and those who can't...

Re: Drawing ellipse in C# .

Christian Graus5-Jul-09 0:21

Christian Graus

5-Jul-09 0:21

Well, it sounds like you're doing it wrong. How are you drawing it, and why can't you make the code conditional ?

Christian Graus

Driven to the arms of OSX by Vista.

"! i don't exactly like or do programming and it only gives me a headache." - spotted in VB forums.

I can do things with my brain that I can't even google. I can flex the front part of my brain instantly anytime I want. It can be exhausting and it even causes me vision problems for some reason. - CaptainSeeSharp

No of Users connected in MS-Access Database ?

suleh4-Jul-09 20:50

suleh

4-Jul-09 20:50

Hello

I want to get no of users and user names connected to ms-access databse from C# program. Also whether I can open MS-Access databse exclusively.

Thanks

Suleh Kiran, Calicut (Kerala) India.

question about setup

sumanpandey4-Jul-09 20:47

sumanpandey

4-Jul-09 20:47

hello .....all

can anybody hlp me to tell the fact tht how can i add condition (which is sumthing related to find MAc id) before installtion of the setup ... Cry | :((

thanx in advance Smile | :)

soni pandey Smile | :)

Re: question about setup

Manas Bhardwaj4-Jul-09 21:06

Manas Bhardwaj

4-Jul-09 21:06

You may have a look at the Custom Actions[^]

Manas Bhardwaj
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validating xml and ignore some elements with out changing schema

shmely4-Jul-09 20:12

shmely

4-Jul-09 20:12

Hi ,

I am validating an xml that express an an invoice document.
this documnt always have header and lines.but somtimes (not always) have serial numbers.
When I am validating the xml against the shcema I want the validator to ignore if the serial number element does not exist.
I can't change and I don't want to change the schema Since i am getting it from a third party software.
What can I do to ignore it?
see, my code and a part of the schema below:

I am using this code to validate xml file to xsd file:
private void ValidateSchema(string filePath)
{
XmlReaderSettings settings;
XmlDocument doc;
XmlReader reader = null;
try
{ settings = new XmlReaderSettings();
settings.Schemas.Add(null, m_sSchemaPath);
settings.ValidationEventHandler += new ValidationEventHandler(settings_ValidationEventHandler);
settings.ValidationType = ValidationType.Schema;
doc = new XmlDocument();
reader = XmlReader.Create(filePath, settings);
doc.Load(reader);
doc.Validate(settings_ValidationEventHandler); }
finally
{
reader.Close();

}
}
this is part of the the XSD(a few complex type elements):

<element name="Documents">
<element name="Documents_LINES">

<element name="SERIAL">

thanks in advanced,
A Y

How to store & retrieve Paragraph Data using XmlSerializer in XML

Andy Rama4-Jul-09 20:09

Andy Rama

4-Jul-09 20:09

Hi to all,

I am writting a C# Windows Application in which it uses XML to store & retrieve Student Data (like Name, Addres, DOB, Educational Details, Economical Conditions, etc).

To store & retrieve data from XML, I am using XmlSerializer class.
But some student data are in form of paragraph (like Educational Details, Economical Conditions, ..). How to store & retrieve that data using same XmlSerializer class?

Thanks & Regards,
Aniket A. Salunkhe

Re: How to store & retrieve Paragraph Data using XmlSerializer in XML

Christian Graus5-Jul-09 0:22

Christian Graus

5-Jul-09 0:22

It's just XML. You can put carriage returns inside the data.

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