I am creating an application that is drawing different types of lines in a Panel called Panel1 and realized that everytime I call Panel1.Invalidate() alll the lines that are currently drawn on the display during runtime are cleared then redrawn every time.Is there anyway to generate a PaintEvent without calling an InValidate?
View 2 RepliesI call Me.Invalidate() in the property setter of a custom control (inherits from ProgressBar) but it only causes the control to paint on screen about 1 in every 10 times (or less) whereas there are far more times that the code enters the painting routines (i.e. only on some occassions do the painting routines cause on screen changes). I am using my own Painting routines, not using ProgressBarRenderer.
On the Inherited ProgressBar I set Minimum to 0 and Maximum to 1000 and use a timer to increment Value by 1 on each tick (100ms). Therefore Me.Invalidate() should be called after every tick and hence the 'progress' of the bar should be quite smooth - 1000 small increments as it fills the bar should be pretty small changes and hence appear fairly smooth.
However, what happens is that the control only changes on screen about 1 in 10 of the times that Value changes. The control also writes the progress as a % (integer) onto its surface and each change in the % text is accompanied by an increase in the visual progress. I think this apparent synchronisation is coincidence though, since using Console.WriteLine I can see many many calls to the Painting routine but a few of them actually cause a visual change on screen.
I have tried slowing the timer down to 1000ms but this hasn't changed anything other than there are far more than 10 calls to the painting routines between actual on screen changes.
I am using PointF, RectangleF and SizeF to avoid 'rounding errors' and hence blocky progress from using the Integer versions of those structures.
There's some stuff from the Output window (using Console.Writeline) near the bottom of this post that shows that at the beginning there is 1 OnPaint per Invalidate. Later on (somewhere around 1% and 5% progress) it changes to having several OnPaint calls between Invalidates. So I certainly don't appear to be short on calls to OnPaint. I only appear to be short of actual OnScreen changes.
The Painting routines use the RectangleF structures to create GraphicsPath objects, which are used to create a Region that is then filled by e.Graphics.FillRegion.
Possibilities I can think of:
1) The painting events are too frequent to allow screen udpating, but this doesn't seem likely since 1000ms timer ticks didn't help
2) GraphicsPath and / or Region objects aren't 'precise' and hence a range of similarly sized RectangleF objects create essentially identical GraphicsPath objects (or the same problem when moving from GraphicsPath to Region)
3) Erm, not sure...
Here's the Setter code:
Public Shadows Property Value As Integer
Get
Value = MyBase.Value
[Code].....
I have the following VB.NET code to set and read objects in cache on a per user basis (i.e. a bit like session)
Public Shared Sub CacheSet(ByVal Key As String, ByVal Value As Object)
Dim userID As String = HttpContext.Current.User.Identity.Name
HttpContext.Current.Cache(Key & "_" & userID) = Value
End Sub
[Code]....
I use these functions to hold user data that I don't want to access the DB for all the time. However, when the data is updated, I want the cached item to be removed so it get created again.
How do I make an Item I set disappear or set it to NOTHING or NULL?
I have adopted a technique where I pass existing objects to forms so that they can display the object's content and allow the user to alter it if necessary. The form is not bound to the object, so when it comes time to act, the form sweeps up the content of its controls and puts them into the object. The object is then validated and any issues reported to the user. If the object is valid, it may be handed back to the caller so the caller can refresh a view/list/etc.
So far, so good. However, if the form's content, or lack of, creates an invalid object and the user does not correct it, maybe cancelling the form, there's a chance the form will hand an invalid object back to the caller. This is not good.
Essentially I'm looking for an elegant and efficient way of either leaving the object as it was or rolling back if the user cancels the form/action.
I have considered a range of techniques, each with many pros and cons. I'm keen to consider some other views.
To refresh or invalidate only a region of the form.sometimes I will need refresh all the form, but in some situations only specific regions of the form..I saw some samples on the Microsft site, but I don't understood.I use VB .net 2008
View 3 RepliesHow to generate the API of my Site ... www.volvobusesindia.com so that i can provide my site API to agents so that cthey can vbook tickets using our API ?
i want the bus booking search box appear in the site will be displayed in others website ?
I am writing an encryption application that requires a 64 bit key. I am currently using the following code to automatically generate a key.
Function GenerateKey() As String
' Create an instance of a symmetric algorithm. The key and the IV are generated automatically.
Dim desCrypto As DESCryptoServiceProvider = DESCryptoServiceProvider.Create()
[code]....
I am wanting the user to create their own key. Can I convert a user defined password (a string) into a 64 bit key that can be used?
I want to build a kind of a tone generator to tune my Ukulele (NERD allert, sorry for that).I know there are enough tone generators available but since a Ukulele has only 4 strings and not in the same order and tone as a regular guitar, they won't help me. My objective; to build a small VB.NET form with four buttons and every button will generate a specific tone.I've already tried Console.Beep etc [URL] but all I hear; no beep.As seen on the page at this link: QuoteThe Beep method is not supported on the 64-bit editions of Windows Vista and Windows XP.As far as I know, I'm not running a 64-bit Windows Vista, however, I'm running on a 64-bit processor.
I've tried Google (one of my best friends, but we seem te be in a separation?) but all I can find are examples in C# (since it is about music, C# is a regular tone, however I don't know anything about C# as a programmers language...) and the examples there are in VB.NET are about extreme big applications like digital piano's etc.
I want to generate a unique ID in VB.NET that starts with ASXXXXX where XXXX represents a number. The number has to start in an orderly fashion. This ID will then be stored in a SQL Server express table.
View 8 Replieshow can generate (and display) images on the fly for simple charting, resizing etc?
View 3 RepliesI'm using the below function to generate an MD5SH1 hash for SQL backup files.This works well, has progress report etc but is slow if using large files.
Could I generate the MD5 at the same time as SH1 rather than having to process the file twice, doubling the time taken? What about converting an MD5 result to SHA1?
Imports System
Imports System.IO
Imports System.Security.Cryptography
Imports System.Text
[Code]...
I am a beginner in VB.NET. I have made a small project and now i would like to make some reports to complete the project.
how i can work with reports in VB.NET. I want to retrieve data from SQL Server 2000 using Stored Procedures and generate a report in VB.NET.
Is it possible to generate the sample xml(Used as Request xml for web service)from the xsd using vbscript code?
View 4 Repliesi would like to generate a very simple report with some images and text and i am wondering if there is a way to generate a pdf file with vb.net?
View 4 RepliesI'm very dumb in vb.net or any .net languages. Actually while I was creating a package using SQL Server Integration Services, I had a problem. This problem can be solved using VB.net script.
Here is my scenario
I've a database table like this
ColA ColB ColC
[code].....
I want to generate a matrix (7,4) with this output: (7lines and 4 columns) that has this structure(with this values)Column A1 and row B1 has 2 values (1 8 ), column A2 has 2 values (2 7 value in column A2) , column A3 has 3 6 value column A4 and row B1 has 4 5 value. And so on.How I can generate this matrix: [code] So my question is which condition to put to generate this matrix of this form.A cell A1,B1 contains two values (1 and 8 for example in cell B1).
View 1 Replieshow to generate the formula. want to use arraylist to store and for loops to loop the formula til the system can detect which staff it should giv the ticket to..below is the scenario:this is a helpdesk system..so each ticket they submit muz be auto assigned to a staff to attend their ticket..each staff has a different quota..so i came out wid this algorithm on hw to determine who the ticket shld go to..
for ex: i set one ticket's quota is 7%
staff A's quota - 47% staff B's quota - 35% staff C's quota - 18% so to knw how many tickets A get den B getx 1 ticket and how many tickets B get den C gets 1i came out wid a calculation like this -
Staff A - 47% / 7% = 6.7(max no.of tickets he can receive foe a period of time)
Staff B - 35% / 7% = 5
Staff C - 18% / 7% = 2.5
so first i compare A&B whr i took 6.7/5 = 1.3 -> so every 1.3 ticket A gets,B gets 1 ticket den i compare B&C whr i took 5/2.5 = 2 -> so every 2 ticket B gets,C gets 1 ticket i wanna implement this concept in my code..but i dunno how to come up wid this formula..
All I want is to generate an ID to my listview per row it is possible? For example I have 10 records in listview and I want to add an ID per row in randomly... Here's my sample picture... but it's wrong...coz' at the column 3 it's a repeating ID...
View 1 RepliesThis is my Vb.net Project for company i want to generate code for each individual slip so that i get one field as unique field for that i want to use date & slip no to generate unique key. i have attached screen shot my project in this date 21/12/2011 & slip no is 12 now i want to generate unique number as 21121112 (i.e 21/12/2011 as 211211 & slip no is 12 appended at the end)if u have code then attach with your solution
View 3 Repliesbasicaly i'm on a project which involves generating programs on the fly from a website, these programs will have the ids of the logged in users.To do this, I found a little trick, which is having a vb.net program running on my windows server communication with my website's database and generating another executable then send it back to the client.Anyway this is just some boring introduction, basically my question is how can I generate an executable from my vb.net executable?
View 6 RepliesOn Stack Overflow, I found the question Generate a receipt number in this range.In answers (from Adam Maras) I find this code (very interesting for me):
Private Const FirstReceiptNumber As String = "GA00000"
Public Function GenerateReceiptNumber(ByVal lastNumber As String) As String
If lastNumber.Length <> 7 Then
[code]....
But show me error in GenerateReceiptNumber().ow do I use that code to give me a receipt number in TextBox1 when I open this form?The receipt number must be +1 next time with Form_Load.
I want to add a button (ButtonCalculate) to make the user select this button to generate the loop for calculating the sum.
Private Sub TextBox1Integer_TextChanged(sender As System.Object, e As System.EventArgs) Handles TextBox1Integer.TextChanged
Dim OddSum As Integer = 0
[Code]......
[Code]...
This is not working, I am getting a syntax error when i try to do for each dr in diarytable.rows
Generating item codes for my inventory system became complex when the panel said that this must be the format of the generated ID number: "CATEGORY-ITEMNAME-ITEMINDEX" For example: School Supplies - Coupon Bond short- Second Item in the database would result to an item ID : SCS-CBS-002.
View 2 RepliesHow can i auto generate number in vb.net
View 4 RepliesI have a large .NET source tree (185 C# and VB projects, of which 60 are apps or websites) that i want to create a wix setup for. The general idea is to have 1 setup msi and to make each executable a feature, and to have each app be installed in a separate directory. like
%progfiles%/company/app1
/app2
/app3
[code].....
Some libraries are used by multiple apps, so the DirectoryRef would have to be pointing to multiple directories, and multiple DirectoryRefs (with different ids) would have to be pointing to the same directory (found directory alias trick), both of which seem impossible.I get the distinct impression I'm going about it the wrong way, or that I'm missing some deeper insight. (No suprise as my wix-fu is a full 3 days old)
How to generate Rijndael KEY and IV using a passphrase? The key length must be in 256 bits.
View 5 RepliesI get this error mssg; Microsoft.Net Framework//An unhandled exception has occurred.Cannot Generate SSPI Context.The SQL Server is on a SERVER and my program is on the client machine.I believe it (Client machine) is loosing its network connection. Because once I re-bot the system it connects fine.I am going to try and PING the SERVER when it comes up next to check the connection.I tried googling this for a resolution but to no avail.Do u think I will have to reload the OS on the client machine or just the Framework.
View 1 RepliesI have a function in VB.net that returns a password hash. I need to make a web interface to the same database and I'm not sure how to return the same hash in PHP. Does anyone know both languages enough to convert this to PHP?
Code:
Public Function GenerateHash(ByVal SourceText As String) As String
'Create an encoding object to ensure the encoding standard for the source text
Dim Ue As New UnicodeEncoding()
[Code].....
I have created a program that merges files and I have decided to output the results as an HTML document so that it is legible. I have achieved this output using System.IO.StreamWriter and creating a textfile with all the html formatting and in-line CSS and saving it with the .html extension like so:
[Code]...