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I'm getting some unpredictable results when I divide two Doubles. Here is an example.
If
Dim a() As Double = New Double() {30.0, 3.0, 0.3, 0.03, 0.003, 0.0003}
Dim b() As Double = New Double() {20.0, 2.0, 0.2, 0.02, 0.002, 0.0002}
then according to .NET
a(0) / b(0) = 1.5
a(1) / b(1) = 1.5
a(2) / b(2) = 1.4999999999999998
a(3) / b(3) = 1.5
a(4) / b(4) = 1.5
a(5) / b(5) = 1.4999999999999998
Not a big difference in magnitude but my code also involves rounding the results which really throws things off.
Any help with an explanation and/or solution is greatly appreciated.
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This is because the internal representation of floating point numbers is not exact. There are many articles all over the 'Net about IEEE storage format and why this happens.
A workaround would be to round the results off to the number of decimal places you want using Math.Round(), or use Decimal types instead of Double.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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How do I trap the each key pressed in the particular cell only of msflexgrid
in vb6
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Hi Everyone,
I am beginner to dotnet. I just started developing web pages in VB.Net. I am planning to use
TabStrip control as a main menu page. I have 3 tabs like this,
HOME DATAENTRY REPORTS
I would like to populate few reports(Report1,Report2 etc) under REPORTS tab. when a user click or place mouse on Reports, sub menu options should display.
I need your great help. I am trying to find info for this. even i am not sure wheather i can do in Tabstrip control.
I appreciate your help.
Thanks
Bob
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You question would be better handled in the ASP.NET Forum. I've never used the TabStrip control, but I don't believe it'll do what you want. I think your going to have to implement dropdown menus in JavaScript yourself.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Thank your for your response. Let me post this in ASP.NET Forum to see if anyone had similar req before.
Thanks
Bob
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I've performed the scanner interfacing through VB.NET using WIA. The scanning is performed using the Windows own Scanner Wizard dialogbox. This dialog box obviously has its own options, including the preview of the scanned image.
My question is that, is there anyway to edit or manipulate this dialogbox through the code, so that I can disable certain options?
OR
Is there anyway that i can directly scan the image with any default options of my choice without any wizard, and display the scanned image directly in my form?
thanx in advance
☺«««DTA»»»☺
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azam316 wrote:
My question is that, is there anyway to edit or manipulate this dialogbox through the code, so that I can disable certain options
No, there isn't.
azam316 wrote:
Is there anyway that i can directly scan the image with any default options of my choice without any wizard, and display the scanned image directly in my form?
Search the articles! A quick search turned up .NET TWAIN image scanner
[^].
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Maybe I am just not up to speed w/ .NET, but when I create my Performace Counters and Category, they load just fine, I can see them in the WMI performance Monitor, however they do not display the activity that is incrementing them. WMI reports that the class has no methods. I can not seem to find any information on what those methods would be? Can anyone point me in the right direction?
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Im trying to implement an encryption technique in my collage and i have to get the ascii number of the character to aplly the algorithem to that character ..
like in c++ for example ..
the ascii code of the a=65 and b=66 and so on ..
if any one have an idea about how to get this ascii value in vb.net .. plx reply me ..
thanx
لا اله الا الله محمد رسول الله
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try using Val = ASC(Char) (That's if I remember correctly!)
"Now I guess I'll sit back and watch people misinterpret what I just said......"
Christian Graus At The Soapbox
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your answer is completely correct.
Asc() function returns ascii code for a character and Chr() function does the reverse: returns the character for an ascii code.
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Hi!
My Problem is that i'm using MdI Form and on Mdi Form i'm Using A Toolbar that will work in same way in my entire application such as that if user press Add button on Toolbar of Mdi form then Add Function/sub of Active MdiChild Form should be called similarly some other Button works but when i'm going to do this i'm still really failed to call function of Active form (Form1) from MdiForm(Form2).
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Hi!
My Problem is that i'm using MdI Form and on Mdi Form i'm Using A Toolbar that will work in same way in my entire application such as that if user press Add button on Toolbar of Mdi form then Add Function/sub of Active MdiChild Form should be called similarly some other Button works but when i'm going to do this i'm still really failed to call function of Active form (Form1) from MdiForm(Form2).
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How to create setup files(installshield) after developing a program???
Ashish
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For a simple installer, you can use the Setup Project that comes with VIsual Studio .NET. For more complex project, I HIGHLY suggest using a 3rd party product like InstallShield or Wise for Windows Installer.
For a simple project, walk yourself through HOW TO: Build an Installer by Using Visual Basic .NET[^] on MSDN.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Howdy.
Perl has a nifty virtual interface for RDBMSs called DBI - it abstracts the common functions from most DBs and wraps them with a common interface. It's slick when you don't know what DB your app will be used with.
I have a VB.Net app that needs to be DB independent as well, that is, I will not know what DB my user has at the data layer. Is there an equivalent to the Perl DBI lib for VB?
TIA.
Gus
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Yes , it's called ADO.NET and includes such database agnostic interfaces as IDbConnection, IDbCommand, IDbTransaction plus many more.
System.Data namespace
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I'm currently working on a project that sends a JPEG to an image correlation app. I load an 8-bit grayscale BMP and save it as a JPEG with the GDI+ libraries but it saves the JPEG as a 24-bit true color image. Can GDI+ write a 8-bit JPEG?
Here's my VB code snippet:
' Create the GDI+ bitmap
' from the image handle
lRes = GdipCreateBitmapFromHBITMAP(pict.Handle, 0, lBitmap)
If lRes = 0 Then
Dim tJpgEncoder As GUID
Dim tParams As EncoderParameters
' Initialize the encoder GUID
CLSIDFromString StrPtr("{557CF401-1A04-11D3-9A73-0000F81EF32E}"), tJpgEncoder
' Initialize the encoder parameters
tParams.Count = 1
With tParams.Parameter ' Quality
' Set the Quality GUID
CLSIDFromString StrPtr("{1D5BE4B5-FA4A-452D-9CDD-5DB35105E7EB}"), .GUID
.NumberOfValues = 1
.type = 4
.Value = VarPtr(quality)
End With
' Save the image
lRes = GdipSaveImageToFile(lBitmap, StrPtr(filename), tJpgEncoder, tParams)
' Destroy the bitmap
GdipDisposeImage lBitmap
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When I display a date from the database I get the date and time. I've been able to create a binding object with events to get rid of the time in about half of the cases.
Private Sub XBINDING_format(byVal sender as Object, by Val e
As System.Windows.forms.converteventargs) handles xbinding.format
e.value = Format(e.Value, "MM/dd/yy")
DIM WITH EVENTS XBINDING AS BINDING
XBINDING = NEW BINDING ("TEXT", DS, "ADATE")
TXT1.DATABINDINGS.ADD(XBINDING)
This works fine if the value is not null. So, I put a try - catch trap to just display the database field directly if the above routine fails.
On about half of the date fields this works, the other half get an error that dosn't seam to have anything to do with the date problem
"Additional information: Argument 'Expression' is not a valid value."
If I comment out the routine everything works find. (Except for having the time in my textbox.
The work "Expression" isn't in any of the code. And, the online help talks about everything but this problem.
Anyone have any ideas?
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This is what happens when you blindly catch exceptions. Instead, check if the value is null yourself, and deal with it explicitly in your code.
Christian
I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer
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hi!!
can anybody help me in establishing connection of oracle 8i with VB.Net
i need code for this purpose if anybody can give me that???
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i believe there is a set of oracle data classes available on msdn. run a search there to have a look for them. otherwise you can always use the oledb namespace.
check for connectionstrings here.
good luck!
-jim
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I use OleDb myself. But it's rather slow. You can find tons of example for that. Or you can try using the wizards for database adapters.
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Looking for a way to develop new graphical / user controls in C# or VB.NET and put them onto existing VB 6 forms.
Current project is a VB exe with many forms - long term goal is to port to .NET but interim solution is to develop new code in .NET while we migrate over.
Problem is I can't find a way to add new controls to the form... Is this possible?
It is possible to open new .NET forms from VB and reference .NET class libraries.
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