updating label in main form - C# Discussion Boards

Re: Object reference not set to an instance of an object

5-Jul-04 4:53

Colin Angus Mackay wrote:
Also, remeber that indexes in C# are zero-based.

To be complete, indexes in .NET are all zero-based.

[EDIT] Before the ignorant start flaming me for "indexes" check your dictionary. "Indexes" is a perfectly viable alternative to "indices". It's happened before. [/EDIT]

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exhaulted5-Jul-04 5:00

Re: Object reference not set to an instance of an object

5-Jul-04 5:00

I might be completely wrong (usually am) but i think you need to set the ans[x] = to an instance of the answer class before you can do anything with it. Because it has not been instantiated yet you get your Null Reference Exception.

Try initializing each element in the array to a blank Answer class.
This sounds right to me but without actually trying it i don;t know.

Let me know how you get on,

Cheers

Kev Pearman MCP

rturner0035-Jul-04 5:54

rturner003

5-Jul-04 5:54

Thanks to you and all who replied

Robert T Turner
South Gloucestershire Council

updating label in main form

Jason Ranin5-Jul-04 4:16

Jason Ranin

5-Jul-04 4:16

Hi, I have a trivia program wherein i have main form containing a label for player's winnings. the trivia questions are separate forms that is launched when the corresponding button from the main form is clicked. the question forms are timed and once the time has expired, it checks for the correct answer. a price (i.e. $100) is set for each correct answer. the problem im having is that this price is not being updated on the main form label after the time has expired. Can anyone help me please ASAP?
thanks.

Sincerely,
Jason C. Ranin
Software Quality Assurance

Re: updating label in main form

exhaulted5-Jul-04 4:24

Reading TOC and text from Word 2002

5-Jul-04 4:24

Try calling the TextBox.Invalidate() method, this will force the text box to be re-drawn. If that doesn't work then it may be a problem with how you are passing the value into the text box.

Kev Pearman MCP

Steven_T5-Jul-04 2:34

Steven_T

5-Jul-04 2:34

Hi,

I am trying to inventory a directorty with Word documents.
This is on of my first programs in VS, but this is what I've got:

Reference to Interop dll's for Word 2002.
Getting the files from the directory.
Opening the word docs one by one.

But then I'm having trouble getting the Toc of the document.
I want to insert the document per paragraph from the toc in a db.

I have read on MSDN but still no luck.

Does anyone have any tips for me?

Steven T

How to add custom properties in PropertyGrid at Runtime

ilmian5-Jul-04 1:34

ilmian

5-Jul-04 1:34

Hi,
I have some class in my project like Executive, Manager etc. Each class has some perdefined properties like FirstName, LastName etc. I assign the object of my classes to the property grid, to have these perfined properties in the property grid.
The problem is that i want to add some other properties like Address, Phone, Email etc to my classes (Manager, Executive) at runtime, so that these properties can also be accessed through the property grid. How can i do this.

Thanks in advance,

Omar Rehman

how to get my computer speed

maro-gb5-Jul-04 1:10

maro-gb

5-Jul-04 1:10

Please I need to know how to get my speed on the network.

Re: how to get my computer speed

Heath Stewart5-Jul-04 5:29

how to make a customized control box

5-Jul-04 5:29

The only way to accurately measure this property is to actually measure it. You need to send data of a known size to a network resource (i.e., your gateway/router or an intranet server) and measure how long it takes to completely send. You should also measure how long it takes to receive this data. You do this over and over again and measure the running average. This is how download managers calculate how much time is left while downloading a file.

You can also use a PerformanceCounter using the "Network Interfaces" category, the "Current Bandwidth" counter class, and the instance of the NIC (network interface card), which performs many of these calculations for you. This is not the actual bandwidth, however, this is only the max bandwidth as reported by the NIC.

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generics

noraguta5-Jul-04 0:21

noraguta

5-Jul-04 0:21

Hi,
I'm playing around with generics in .NET 2 beta framework.

in 1.1 i have expresion :
propertObjArr[i].PropertyType.IsSubclassOf(typeof(System.Collections.CollectionBase))

to find all properties in object which have been collections at runtime. Then i changed some collection into generic collection.but there is no abstract class for generic collections.My question is how to find out which properties are generic collections.

Re: generics

noraguta5-Jul-04 1:52

noraguta

5-Jul-04 1:52

nevermind
i found propertObjArr[i].PropertyType.HasGenericArguments solve my problem.

Imran Ahmed Khan5-Jul-04 0:11

Imran Ahmed Khan

5-Jul-04 0:11

Hello,
Can any one tell me dat is there a way that i can make my own control box with customized minimize, maximize/restore & close buttons & add this control box to any Form. Is there any class which represents Control Box or do i have to inherit generic windows Forms class or ????? Confused | :confused:

In short i want to put my own buttons (some fancy styles) where the minimize, maximize/restore & close buttons are on the top right of the form. Ony way is to set the ControlBox property of Windows form to false but then my menus are hidden behind the control box picture which i inserted in order to show a dummy control box.

Please help me out on this.
Regards.

Imran Ahmed Khan.

Re: how to make a customized control box

Heath Stewart5-Jul-04 5:17

5-Jul-04 5:17

There is nothing in the .NET Framework BCL to help you create your own control boxes. You should extend the Form class, override WndProc, and handle the WM_NC* notification messages to draw in the non-client are of the window frame. There are many native APIs that you must P/Invoke, as well as many supporting structs you must define (like RECT, which cannot be replaced by System.Drawing.Rectangle - their fields have different meaning).

There are article on the 'net (try a google search) that describe how to do this using C/C++. If you know C/C++, I would suggest creating a Managed C++ project and using both managed and native code to extend the Form class to do what you need. You could then reference that assembly and extend or use that class in any managed language.

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Printing

exhaulted5-Jul-04 0:06

5-Jul-04 0:06

Hi all,
I'm trying to right align a string on a page and i know i can do it if i can find the width of the string i am printing in pixels (or another GraphicsUnit measurement). Does anyone know how i can find this out or does anyone have another way of doing this.

Cheers

Kev Pearman MCP

Re: Printing

exhaulted5-Jul-04 0:21

Converting Pixels to 100/Inch

5-Jul-04 0:21

OOPS!!
Just read down the forum and saw the previous post on getting the size of a string in pixels.
This should be fine for what i want.

KP

exhaulted5-Jul-04 0:59

5-Jul-04 0:59

OK,
i can get the size of the string in a SizeF object using the Graphics.MeasureString method.
The problem i have now is that the page bounds are in 100ths of an inch and i have the size of the string in pixels. My idea was to use the drawstring method and in the place of the x co-ordinate i was going to use:
e.MarginBounds.Right - stringSize.Width,
Obviously this isn't going to work because the 2 values are in different units. Is there a method that i can use to convert a value in pixels to a value in 100ths/Inch or vice versa.

Cheers

KP

Pain_Elemental5-Jul-04 2:19

Pain_Elemental

5-Jul-04 2:19

I have a similar problem: I have the size of a bitmap in pixel, but I need to know the size in millimeters.

Some conversion can be done using the PrinterUnitConvert class, but unforunately it doesn't work with Pixel Frown | :(

-------------------------------------------
The light at the end of the tunnel has been switched off temporarily due to budget problems...

Pain_Elemental5-Jul-04 3:53

Pain_Elemental

5-Jul-04 3:53

I found this in the book "windows programming with C#" by Charles Petzold:

PointF ConvertMillimtersToPixel(Graphics grfx, PointF pointF)
{
    pointF.X *= grfx.DpiX / 25.4f;
    pointF.Y *= grfx.DpiY /25.4f;

    return pointF;
}

Maybe you can enhance it for your needs...

-------------------------------------------
The light at the end of the tunnel has been switched off temporarily due to budget problems...

exhaulted5-Jul-04 4:21

5-Jul-04 4:21

if i convert my page width to milimetres then the above method should work fine.

Thanks for your help, I hope this sorted your problem as well.

Cheers

Kev Pearman MCP

Heath Stewart5-Jul-04 5:38

5-Jul-04 5:38

The correct way is to P/Invoke GetDeviceCaps and query for the logical pixels / physical pixels using LOGPIXELSX and LOGPIXELSY. Hard-coding numbers like the other guy did will not work on every system, especially these days when more and more displays are moving to 120 DPI as opposed to the currently common 96 DPI.

I've posted code to correctly get the number of pixels per some physical unit (twips, actually, which is 1/1440 of an inch) before. See an example at http://www.codeproject.com/script/comments/forums.asp?msg=829941&forumid=1649#xx829941xx[^].

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exhaulted5-Jul-04 6:06