C# Discussion Boards - CodeProject

Colin Angus Mackay2-Feb-04 4:08

2-Feb-04 4:08

Arjan Einbu wrote:
I know the rules of OO, but i believe rules can be broken sometimes if it serves a greater purpose. (Less code, fewer sources of error, greater maintainability.)

Many years ago I worked with a programmer that would take this statement and abuse it to the extent that everything would be public! OMG | :OMG:

He'd interpret it as: Less code == fewer sources of error == greater maintainability

You make a very good argument in this case for allowing the public readonly field. However by the time I thought through all the possible senarios for each member variable I create and decide whether to fully encapsulate it or decide that it is safe to expose I could have written a default compliment of getters/setters for them.

--Colin Mackay--

EuroCPian Spring 2004 Get Together[^]
"You can have everything in life you want if you will just help enough other people get what they want." --Zig Ziglar

Re: Automatically creating classes ?

Arjan Einbu2-Feb-04 4:36

Arjan Einbu

2-Feb-04 4:36

Colin Angus Mackay wrote:
Many years ago I worked with a programmer that would take this statement and abuse it to the extent that everything would be public!

Well, he didn't get it... neither about OO or maintainability. Mad | :mad:

I hope you understood it the way i meant it...

And yes; Creating the getter for this one probably is better, and isn't that much work. (Virtually none with the right tools[^] Smile | :)

)

Have a look at my latest article about Object Prevalence with Bamboo Prevalence.

Re: Automatically creating classes ?

Colin Angus Mackay1-Feb-04 1:35

Colin Angus Mackay

1-Feb-04 1:35

Desmond,

If you elected to receive response notifications via email the email you got will contain slightly incorrect code. I have corrected the code, but you need to view it on the forum.

--Colin Mackay--

EuroCPian Spring 2004 Get Together[^]
"You can have everything in life you want if you will just help enough other people get what they want." --Zig Ziglar

Re: Automatically creating classes ?

Andres Coder1-Feb-04 4:47

Andres Coder

1-Feb-04 4:47

By the way, is there a way to "shorten the patch" to the singleton ? I mean, I have to write right now MainMameSpace.MyClasses.PropertiesClass.Instance.SomeFunction, but it would be much easier if it could be just MainNameSpace.PropertiesInstancel.SomeFunction.

Isn't it possible to access the ProperitesClass.Instance through a pointer or something ?

Re: Automatically creating classes ?

Colin Angus Mackay1-Feb-04 5:01

Colin Angus Mackay

1-Feb-04 5:01

At the top of the file you can add using statements so that you can short circuit the path to the classes. If there is any ambiguity, for example two classes with the same name but in different namespaces, you will still have to use the full path.

For example:

using MainNameSpace;
using MainNameSpace.MyClasses;

then later in your code you can just put:

PropertiesClass.Instance.SomeFunction()

C# only permits pointers in unsafemethods. However if you are going to use the instance a lot then you can just assign it to a variable as normal. e.g.

    PropertiesClass pci = PropertiesClass.Instance;
...
    pci.SomeFunction();

I hope this points you in the right direction.

Regards,
Colin.

--Colin Mackay--

EuroCPian Spring 2004 Get Together[^]
"You can have everything in life you want if you will just help enough other people get what they want." --Zig Ziglar

Virtual colums in a datagrid?

Franz Pentenrieder31-Jan-04 12:02

Franz Pentenrieder

31-Jan-04 12:02

hi, im using a datagrid generated from a XML file using the VS XSD builder. now i want to add a "virtual" colum that add's some extra information, i only need this information on the runtime so i don't wanna add it to the XML file.

i have read some examples with "BindingContext" and "Expression" but this examples are mostly DataGridBoolColumn and no TextColums.

dose anybody knows a tuturial or have some example code?

Re: Virtual colums in a datagrid?

Heath Stewart2-Feb-04 4:21

Heath Stewart

2-Feb-04 4:21

First, you should consider using DataGridTableStyle(s) to control exactly what the user sees (for instance, if you have a PK in your strongly-typed DataSet as a numeric type, users probably don't need to see that). This will allow you to add columns that aren't bound to the DataSet as well.

You can use expressions in your DataSet and these are not limited to boolean expressions. For more information and examples, see the documentation for the DataColumn.Expression property at http://msdn.microsoft.com/library/en-us/cpref/html/frlrfSystemDataDataColumnClassExpressionTopic.asp[^].

Why I mentioned DataGridTableStyle before is that you could also extend DataGridColumnStyle and make your own class if you need expressions that are supported by DataColumn.Expression. See the documentation for DataGridColumnStyle in the MSDN library at http://msdn.microsoft.com/library/en-us/cpref/html/frlrfSystemWindowsFormsDataGridColumnStyleClassTopic.asp[^].

Microsoft MVP, Visual C#
My Articles

Quick answer for threading

jacal9931-Jan-04 11:35

jacal99

31-Jan-04 11:35

hi i am try to do like this ....
i have a win form textbox and i am trying to write something like "jacal99" using threading with five seconds interval .... the value of thread was thread.sleep(5000);
but when the next charactor try to print in the textbox the first value gone.
i want to pring "jacal99" with five seconds interval .... every charactor...
thx.;)

Mazhar Hussain

Re: Quick answer for threading

OmegaSupreme1-Feb-04 5:37

OmegaSupreme

1-Feb-04 5:37

If you post your code it might be easier to help.

Perhaps your assigning the value of Text property everytime and not adding to it:

yourTextBox.Text = "whatever"; //no

yourTextBox.Text += "whatever"; //yes

Problem with events (I think) ...

Andres Coder31-Jan-04 9:14

Andres Coder

31-Jan-04 9:14

Hi again. Still learning C#. This time I managed to create 2 similar controls. I also have a class PropertiesClass that should change some properties (like color and text) of the controls. But after I have changed a property in PropertiesClass, how can I let the other (two) controls know that I did it ? I remind You that I have several controls that must be updated, not just one. I guess the only chance would be using events somehow ?

From my Borland Delphi days I remember using messages (if property is changed I broadcast the message and the controls respond to it) for things like this, but unfortunately (or luckily) .NET doesn't support them...

Best regards, Desmond

Re: Problem with events (I think) ...

Mazdak31-Jan-04 9:31

Mazdak

31-Jan-04 9:31

Yes, Raise an event is good solution. Search this site for Delegate and EventHandler keywords and you will find some articles about it. Also take a look at C#/Control part too.

Mazy

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A drawing method parameters ...

Andres Coder31-Jan-04 2:44

Andres Coder

31-Jan-04 2:44

I'm very new to C# and I have some questions about writing my own controls (I thought I can learn it best that way). I have two classes - one containing a procedure that paints a area (draws a custom 3D border and background) and another class is a control, witch must call the painting method (that is in the first class) in OnPaint method.

What I don't understand here is how can I pass the area of control as a parameter of the method?

Like in Borland Delphi I would have done it like this:
procedure PaintControl(AreaToPaint: Rect)
Or with two points (one x1, y1 and another x2,x2).

How can I do this in C# ?

If you understood even a little what I'm talking about, please reply....

Re: A drawing method parameters ...

Mazdak31-Jan-04 4:36

Mazdak

31-Jan-04 4:36

On of parameter of your OnPaint is PaintEventArgs (usually named e), and one if its memeber is e.Graphics, pass it to your painting class , you can do painting with it there.

Mazy

No sig. available now.

Re: A drawing method parameters ...

Nick Parker31-Jan-04 4:44

Nick Parker

31-Jan-04 4:44

desmond5 wrote:
What I don't understand here is how can I pass the area of control as a parameter of the method?

You can call get a rectangle object referencing your control like this:

Rectangle rect = this.Bounds;
SomeMethod(rect);
//...


public void SomeMethod(Rectangle rect)
{
   // Your code here...
}

- Nick Parker
My Blog

where is "Project Settings (ALT+F7)" of VC++6.0 in VS.NET ??

Anonymous31-Jan-04 2:17

Anonymous

31-Jan-04 2:17

where is "Project Settings (ALT+F7)" of VC++6.0 in VS.NET.

where i could set exe file name, compiler macros etc

Re: where is "Project Settings (ALT+F7)" of VC++6.0 in VS.NET ??

22491731-Jan-04 2:50

224917

31-Jan-04 2:50

VS.NET IDE -> Solution Explorer -> <right click on root of the tree > properties .

There you are !!

___________________________________________________________

greatest thing is to do wot others think you cant Smile | :)

suhredayan@omniquad.com

Re: where is "Project Settings (ALT+F7)" of VC++6.0 in VS.NET ??

Mazdak31-Jan-04 4:45

Mazdak

31-Jan-04 4:45

Go to Tool menu

Customize---->Option Tab----->Keyboard----->Keyboard Mapping Schema

Select VC++.6 there.

Mazy

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Properties in a Winform

StephenMcAllister30-Jan-04 23:18

StephenMcAllister

30-Jan-04 23:18

Hi,

I am an ex VB programmer learning C# by converting a VB app into C#. In VB I was able to add properties (get and set) to a form so that you could set some properties, display the form so the user could do their bit and the hide the form to read the properties and then close the form.

Is it possible to add properties this way in C#?

I would need to call the form and set the form properties from a button click procedure.

Thanks for any help.

Stephen

Re: Properties in a Winform

Colin Angus Mackay31-Jan-04 1:28

Colin Angus Mackay

31-Jan-04 1:28

Here's a stub of some code to get you creating get/set properties in C#

public string MyPropertyName
{
    get
    {
        return this.myTextBox.Text
    }
    set
    {
        this.myTextBox.Text = value;
    }
}

In this example the property is a string, but it can be any type you like.

The keyword value is special and it contains the value the caller want to set the property to.

To use the property you can just assign and use it like any variable.

Does this help?

--Colin Mackay--

EuroCPian Spring 2004 Get Together[^]
"You can have everything in life you want if you will just help enough other people get what they want." --Zig Ziglar

Re: Properties in a Winform

StephenMcAllister31-Jan-04 19:31

StephenMcAllister

31-Jan-04 19:31

It looked pretty close and so I placed it into the form but I was unable to access the property from my buttom click event. How can I make the property so I can access it from the property click event? What I want to achieve ( using the example given) is frmMyform.MyPropertyName = value;

Thanks.

Stephen

Re: Properties in a Winform

Colin Angus Mackay1-Feb-04 1:40

Colin Angus Mackay

1-Feb-04 1:40

Sorry I don't understand what you are asking.

Properties don't have events. Controls (or any kind of class) can have events. A property is a special kind of a method on a class that you can use to implement get and/or set behaviour.

--Colin Mackay--

EuroCPian Spring 2004 Get Together[^]
"You can have everything in life you want if you will just help enough other people get what they want." --Zig Ziglar

http/ftp download redirection problem

Member 85084030-Jan-04 22:32

Member 850840

30-Jan-04 22:32

I am trying to create a download program similar to flashget but I have come across a problem. Some of the files as you would know are retrieved by using ftp and others http. I have had no problem to download either of these but I found some download links are http to start off with and then are redirected to ftp. Here is the code I am using for http downloads:

<br />
HttpWebRequest myHttpWebRequest = (HttpWebRequest)HttpWebRequest.Create(fullFileName);<br />
myHttpWebRequest.MaximumAutomaticRedirections=100;<br />
myHttpWebRequest.AllowAutoRedirect = true;					<br />
HttpWebResponse myHttpWebResponse;<br />
myHttpWebResponse=(HttpWebResponse)myHttpWebRequest.GetResponse();<br />
myHttpWebResponse.Close();<br />

The problem is files such as http://download.com.com/redir?pid=8132587&merid=50220&mfgid=50220<ype=dl_dlnow&lop=link&edId=3&siteId=4&oId=3002-20-8132587&ontId=20&dlrs=1&destUrl=ftp%3A%2F%2Fftpx.download.com%2Fpub%2Fwin95%2Futilities%2Ffilecomp%2Fwinzip81.exe get redirected to ftp and therefor cause a System.Net.WebException with the following message: "Cannot handle redirect from http/https protocols to other dissimilar ones.". This is understandable, but how do I go about redirecting the http download to ftp. I could do it easily if I were to get the ftp address. It is in the actual url above but in many other cases it won't be part of the url so could someone please help me out in solving this problem?

Intercept incoming html

lustuyck30-Jan-04 22:04

lustuyck

30-Jan-04 22:04

Hi,
I'm looking for a starting point here. I want to 'intercept' incoming HTML on the client, before it's handled by the browser. Is this possible?
Kind regards Big Grin | :-D

,
Ludwig

Re: Intercept incoming html

Dmitriy Kostovetskiy31-Jan-04 9:23

Dmitriy Kostovetskiy

31-Jan-04 9:23

One way to do it is to write a Browser Helper Object[^]. Browser Helper Object can then send message and pass URL to your main application.

Re: Intercept incoming html

Anonymous31-Jan-04 23:34

Anonymous

31-Jan-04 23:34

Thanks for the answer. My initial idea was to have an independent application that runs in the system tray. But I need to go low level for this, I guess WTF | :WTF:

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