C# Discussion Boards - CodeProject

1-Feb-04 10:32

I am assuming you are using C#, hence your question in this forum. You will need to drag a Context Menu object onto your form which will be displayed in the component tray at the bottom. If you want to assign the specific context menu to a control (i.e.; treeview, textbox, etc), those object have a context menu property which you can specify.

- Nick Parker
My Blog

Win32 API functions

zlaty1-Feb-04 10:11

zlaty

1-Feb-04 10:11

Can I use direct Win32 API functions in C# or
I have to write extra dll file in Visual C++
where I can use Win32 API functions?
For examples can I direct in C# write code
for eject CD or I have to write a dll file
in Visual C++ where I can use Win32 API
functions?

Nick Parker1-Feb-04 10:37

1-Feb-04 10:37

Yep, you need to look into the DllImport attribute. Read this following: DllImportAttribute Class[^]

- Nick Parker
My Blog

zlaty1-Feb-04 10:46

zlaty

1-Feb-04 10:46

Thank you very much Smile | :)

))

Mazdak1-Feb-04 10:37

Mazdak

1-Feb-04 10:37

zlaty wrote:
Can I use direct Win32 API functions in C#

Yes. Serach for DllImport in MSDN and this site.

Mazy

"A useless but amusing fact is that if all the DNA in all the cells in a single human being were stretched out it would reach the moon and back eight thousand times." - Steve Jones

zlaty1-Feb-04 10:46

zlaty

1-Feb-04 10:46

Thank you very much Smile | :)

))

Nick Parker1-Feb-04 10:53

1-Feb-04 10:53

Apparently we posted at the same minute but I obviously beat you by at least a second. Smile | :)

- Nick Parker
My Blog

Question on a class communicating with main form

Mazdak1-Feb-04 10:56

Mazdak

1-Feb-04 10:56

Damn to my slow connection. Big Grin | :-D

Mazy

"A useless but amusing fact is that if all the DNA in all the cells in a single human being were stretched out it would reach the moon and back eight thousand times." - Steve Jones

Flack1-Feb-04 9:30

Flack

1-Feb-04 9:30

Hello,

Here is my question.

I have a main class that contains my apps form, call it Form1.cs. The form has some text boxes.

Know, I added another class to my project, Other.cs, and I want this class to write text out to the text boxes on Form.cs.

The textbox is called textOut. I tried to use this line in Other.cs "Form1.textOut.Text = ..." but I get this error: An object reference is required for the nonstatic field, method, or property 'BurCoat1.Form1.textOut'

So do I have to create a Form1 object in Other.cs? One is already made in Form1's main method:
"Application.Run(new Form1());"

I tried to make a global Form1 object in Form1.cs and use that one, but it still didnt work.

Can someone give me some suggestions please or tell me what I am doing wrong?

Thanx a lot,
-Flack

Re: Question on a class communicating with main form

Nick Parker1-Feb-04 9:38

Re: Question on a class communicating with main form

1-Feb-04 9:38

You should look into delegates, events, and eventhandlers. Chris Sells has written a nice article titled : .NET Delegates: A C# Bedtime Story[^] which should help explain some of this.

- Nick Parker
My Blog

Charlie Williams1-Feb-04 15:26

Charlie Williams

1-Feb-04 15:26

You need to get a reference to the form in some way.

Form1.textOut.Text = ... doesn't work because you're addressing the class definition itself, not an instance of it. Creating a new Form1 object in Other won't work either (although it will compile) because it will be an entirely separate intance of Form1, not the one on your screen.

I don't know how your app is set up, but this should give you an idea of how to go about it:

public class Form1{

   public Form1(){
      ...
      Other other = new Other(this);
   }
   //rest of class definition
}

public class Other{

   private Form1 frm1;

   public Other(Form1 frm){
      frm1 = frm;
   }

   public void WriteText(){
      frm1.textOut.Text = "Howdy!";
   }
   //rest of class definiton
}

In that code, you're giving Other a reference to the Form1 instance you're dealing with in its constructor, which is then being saved for future reference in a private field.

Charlie

if(!curlies){ return; }

Question on tabpages and autoscroll.

Flack1-Feb-04 9:20

Flack

1-Feb-04 9:20

Hello,

I have a tab control with five tabpages. On the fifth tabpage I placed some controls (text boxes) out of the tabpages client area. Now, from what I understand, with the autoscroll option on, if there are controls outside of the client area, a scrollbar will appear so that you can scroll and see them. However, when I check the tabpage, I can scroll down to the unseen controls but no scrollbar appears. I use the mouse wheel to go down but I would like the scroll bar to appear so that ppl know that there is more to be seen. Does anyone know why it is not being drawn?

Also, is there an option I can set so that text boxes can only accept integers or at least put up a message when the text box loses focus and the user put in some non-number chars, or do I have to validate that myself?

Thanx for the help,
-Flack

Re: Question on tabpages and autoscroll.

Heath Stewart2-Feb-04 5:10

Heath Stewart

2-Feb-04 5:10

The TabPage won't display scroll bars, but the Panel will. Dock a Panel in your TabPage and add your controls to that instead (cutting and pasting controls works in VS.NET, but you'll have to re-hookup any event handlers).

For the second question, you can handle the TextChanged event and validate the characters one by one (using, perhaps, Char.IsDigit) - which will also validate (and optionally throw an exception) text when assigned programmatically, or for user input just handle the KeyDown event and validate the Keys enumeration passed with the KeyEventArgs.

Microsoft MVP, Visual C#
My Articles

DataSets and Diffgrams

MrJJKoolJ1-Feb-04 5:55

MrJJKoolJ

1-Feb-04 5:55

Hi,

I am wondering if I create a diffgram dataset and I save the dataset to file and then want to commit the dataset to the database. I would assume that I would use a DataAdapter to help commit changes to db, correct?

Is there any special command in the DataAdapter in order to save dataset to database outside of the Update command? Like in the Update property is there any special option type that needs to be included in order to inform the DataAdapter what I am trying to accomplish?

Will a diffgram dataset work for Access as well as Sql Server?

Thanks,

JJ

Re: DataSets and Diffgrams

Mazdak1-Feb-04 6:47

Mazdak

1-Feb-04 6:47

MrJJKoolJ wrote:
Is there any special command in the DataAdapter in order to save dataset to database outside of the Update command?

I think you are talking about DataSet.GetChange() method. Also take a look at DataSet.Merge() , DataSet.Copy() too.

Mazy

"A useless but amusing fact is that if all the DNA in all the cells in a single human being were stretched out it would reach the moon and back eight thousand times." - Steve Jones

I need help pls!! - live radio station

cristiansje1-Feb-04 0:02

cristiansje

1-Feb-04 0:02

i want to create a live web radio station and i dont know where to start
pls help
cristiansje@yahoo.com

Andres Coder1-Feb-04 5:50

Andres Coder

1-Feb-04 5:50

If you're familiar with programming you could investigate other sources (in different languages, like C++ and Delphi) if you can find any.

cristiansje1-Feb-04 9:50

cristiansje

1-Feb-04 9:50

i didnt find any code for this Frown | :(

this why i asked about it

OmegaSupreme1-Feb-04 6:30

OmegaSupreme

1-Feb-04 6:30

I know people who have had success using http://www.shoutcast.com/ but I dont know much about it myself.

Good luck.