I have a a method drawPaper(g, rect,.....).This drawPaper method is called on from another method (PrintPaper method) with the parameters passed on as (e.graphics, rect, .....) i.e drawpaper (e.graphics, rect, .....) why is the method called with the e.graphics argument not with g as per the method.
View 6 RepliesI have a method which requires a parameter to be passed in. I would like to use the Addhandler to call the method through a dynamically created button control's click event.
When I include () in the AddressOf, VS complains: 'AddressOf' operand must be the name of a method (without parentheses).
When I exclude the brackets, VS complains: Method '...' does not have a signature compatible with delegate...
My code:
CODE:
Is there a way to choose between different methods and pass one into another method ?
Sub conditionnal_binding(ByVal list_box_reference As ListBox, ByVal list_box_final As ListBox, _
ByVal dico_source As Dictionary(Of String, List(Of String)), _
ByVal my_methode As ??? )
' DO SOMETHING
End Sub
I wrote ??? because I don't know how to call another method inside a method.
I would like to choose between different "sub-methods". Here is how I would like to use my method :
conditionnal_binding(ListBox1, ListBox3, HTML.dico_basic_attribut, best_method)
conditionnal_binding(ListBox1, ListBox3, HTML.dico_basic_attribut, some_method)
conditionnal_binding(ListBox1, ListBox3, HTML.dico_basic_attribut, another_method)
I'm trying to code a class of RandomNumber. One of the class methods needs to populate a "List (Of RandomNumber)" ... which was passed as a parameter to the method ... with 10 random numbers between 1 and 50. DEAD SIMPLE :)
View 6 RepliesI use Visual Basic 2008, I've got a flickering problem when using Timer and call Graphics.clear routine. I have read many advices to avoid this Flickering problem and try to use them but I still can't fix this problem of flickering.
Here is all of my simple code :
Public Class Form1
Dim r As New Random
Dim b, c As Integer
[code]....
Given the following classes, how can i intercept Class1.SampleMethod's Value from SampleAttribute?[code]...
View 2 RepliesI'm trying to make this code with reflection since I want it to manage Technician and other types too.
[Code]....
Is it accepted to have a method parameter named the same as a property? At least it gives no error, even if in the same letter-case.. How does the compiler distinguish? does it always prioritize the local parameter?
[Code]...
I have a method/sub that takes an object as a parameter, then it scans through a panels controls and trys to find if it is in the window.
Public Sub removetype (ByVal findobject As Object)
Dim types As System.Type = findobject.GetType
For Each ThisCtrl In Flow.Controls 'flow is a panel
[Code]......
So for instance I have this method: LoadFunkyInfo(byval funkyData as string) And I pass it something like this:
LoadFunkyInfo(giantTable.Rows.Item(0).Item("blahName")). Should I do this instead?
dim foo as string = giantTable.Rows.Item(0).Item("blahName")
LoadFunkyInfo(foo)
I read somewhere long ago, that it's better to assign the method to a variable and pass that variable to a method, as opposed to passing the method as a parameter. Is that still true? Or true at all?
This link explains the Encoder.GetBytes Method and there is a bool parameter called flush explained too . The explanation of flush is : true if this encoder can flush its state at the end of the conversion; otherwise, false. To ensure correct termination of a sequence of blocks of encoded bytes, the last call to GetBytes can specify a value of true for flush.but I didn't understand what flush does?
View 3 RepliesI have traditionally coded empty strings like this "", but for a couple of years now, I have been using String.Empty.I also normally never use optional parameters, but I'm refactoring a solution that's tied into my ERP, and I don't want to break anything. One of the changes was to add a parameter to proc, which pushes a new parameter into the method from which it is called. I coded it like this:
Optional BackReferenceID As String = String.Empty
But I got a syntax error "Constant expression is required." I guess String.Empty is non-deterministic??? Anyway, it seems like a bug. The workaround is of course to use double quotes.
I'm currently working on being able to import a DLL written in Fortran into Visual Basic. I've got all the basics down, so now I'm trying to take it a step further. The title basically says it all, but I'll explain what it is I'm trying to do anyways.
For kicks and giggles, let's just assume I want to pass an object that has three double values in it, possibly representing a point in space in three dimensions. In my Fortran method, I want to take that object, print out the x value, then change the x value to 7.5. Here's my Fortran code that does just that.[code]...
What happened when parameter passing. Here is a test project I write.
Public Class Form1
'1.test string
Private Sub btnString_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnString.Click
Dim str1 As String = "x"
[Code] .....
From the project you can see, when pass integer type parameter (value type) into a method , if use ByVal keyword, the value won't change. If use ByRef keyword, the value will change (I can understand it, to my understanding, when using ByVal, It pass the value of the argument to the method; when using BvRef, it pass the address of the argument to the method, so the value can be rewrite)
Well, for the following two scenarios , I can't understand why.
String type is reference type, but it acts like integer type.
Val type is also reference type, but no matter what you use(ByVal or ByRef), the result will be the same.
So my question is what actually passed into method? What's the underlying mechanism about pass parameter? What's the effect of ByRef and ByVal to value type and reference type?
First forms project. My textbook [wrox VB 2880 Programmer's Reference, Rod Stephens] gives snippet that starts with [which intnellisense completes, except for variable names, including trailing 'paint' which seems to be the problem]
Public Class Form1
Private Sub form1_paint(ByVal sender As Object, ByVal e As System.Windows.Forms.TableLayoutCellPaintEventArgs) Handles MyBase.Paint
End Sub
End Class
which generates error :
Error 1 Method 'Private Sub form1_paint(sender As Object, e As System.Windows.Forms.TableLayoutCellPaintEventArgs)' cannot handle event
'Public Event Paint(sender As Object,
e As System.Windows.Forms.PaintEventArgs)' because they do not have a compatible signature
.
Changing 'Private' to 'Public' does not fix the error.
I have already defined in my SELECT statement in TableAdapter to tell it what to do if the parameters are Null:
SELECT a.ID, a.NameID, b.BNameID
FROM a INNER JOIN b
ON a.ID = b.ID
WHERE ((@NameID IS NULL) OR (a.NameID = @NameID))
AND ((@BNameID IS NULL) OR (b.BNameID = @BNameID))
Jst recently i came across the select() method of data table and felli n love with it instantaneously.
Basically I want query the data table on a date field, unfortunately the format of the date string returned from y database in to data-table and the date string i'm passing as inputs are different.
How can i make sure that the data is compared irrespective of the formats ? Can I use something like SqlParameters whoes data type is date for comparison ??
this is what i'm tying :
dim dat as date = "#1/3/2009#"
dt.select("StzDate ='" & dat "'")
entry in datateable dt : StzDate : 3/1/2009 12:00:000
Am I do'in something wrong ??
Also, can anyone redirect me to some site where I can learn a bit more about passing parameters to the select statement,etc...
In VB.NET, it is entirely possible to pass an integer as a string parameter to a method without calling .ToString() - it's even possible to call .ToString without the ()'s. The code will run without a problem, VB will interpret the integer as a string without having been told to. In C#, these would cause compilation errors - you are required to call .ToString() and to call it correctly in that situation before it will compile. Is there a way to make the VB compilation process check for the same things as the C# compilation process? Would it be best practice in a mixed team to force this check?
View 3 RepliesI have created a custom ToolStripProgressBar. It is basically a class inherited from ToolStripStatusLabel, and i paint the 'progress' bar myself (just a simple rectangle). I have tried creating a custom ToolStripProgressBar using different methods including inheriting from both ProgressBar, ToolStripProgressBar and ToolStripControlHost. I always ran into difficulties doing in this way. Inheriting from ToolStripStatusLabel works well, but with one issue...
In order to have the progress bar update in the statusbar, i have to call StatusStrip.Refresh. Trouble is, adds a huge overhead to the drawing of the progress bar graphics. Simply calling the invalidate method of my ToolStripStatusLabel does not seem to render anything to the screen. how to have my graphics draw without calling the refresh method?
This code is for 2008, 2010 and later versions of VB.Net as it uses an extension method.Please note: If you are using an earlier version ( or you do not like extension methods ) please see the next post.Here is the code I posted on Monday April 30th, 2012.>>Now you can specify the startRadius to be
View 7 RepliesI've written the following code to draw a trajectory of points in my program:
Private intNumOfPoints As Integer = 0
Private PtTrajectory(intNumOfPoints) As Point[code]....
*Pos.X and Pos.Y are calculated in the other parts of my program. But, it has a run-time error: "Parameter is not valid".
I have implemented inheritance for two parent classes called Table and Field. Each parent class has several child classes. In the Table parent class, I created a method that expects parameter List(Of Field).
I get an error when trying to pass in parameter List(Of ChildField) to the method that expects a parameter of List(Of Field). The error message is as below:
Value of type
'System.Collections.Generic.List(Of
com.hlb.icisbatch.data.ChildField)'
[Code]....
I'm trying to use a variable that is simply a list of a list of strings.I've declared it as follows:
Dim iRows As New List(Of List(Of String))
Then I'm trying to pass it as a parameter to another method and I've defined the method as follows:
Public Sub Import(ByVal Rows As IList(Of IList(Of String)))
For Each Row As IList(Of String) In Rows
ImportRow(Row)[code]....
Unfortunately, when I try to run that code I get the following error where it tries to pass my variable to my method.
System.InvalidCastException was unhandled by user code
Message="Unable to cast object of type 'System.Collections.Generic.List1[System.Collections.Generic.List1[System.String]]' to type 'System.Collections.Generic.IList1[System.Collections.Generic.IList1[System.String]]'."
When I change the method definition to use the types rather than the interfaces as follows, it works.
Public Sub Import(ByVal Rows As List(Of List(Of String)))
For Each Row As IList(Of String) In Rows
ImportRow(Row)[code]....
So, is it not possible to use generics with interfaces in this way? It works fine as long as I'm not nesting them.
Consider a MyForm class that contains a shadowed implementation of Show(). It also contains a CreateForm() method, which accepts an instance of the form and calls the shadowed sub:
[Code]....
We have a GIS application that has some performance issues. It creates and sends an image to a web browser. We start with a Bing Maps imager, add complex polygons (complete with transparent fill), save the finished image as a PNG, and send it to the browser.
The idea has come up that we could possibly install a graphics card and use DirectX or OpenGL to improve performance. I believe this would be the case even though we ultimately generate an image instead of sending the data the the screen. I believe our processes could still make use of the API and the hardware acceleration it provides. Our process is not unlike what CGI film makers do to render individuals frames of a film, though we simply render a single image and send it, as opposed to the hundreds of thousands of images needed for a single CGI film.
So my question is: would a powerful graphics card and use of DirectDraw or OpenGL provide us a worthwhile performance boost? It can take us 20-30 seconds to render a more complex map. Which is a long time to wait on a web page...
Im working on a project that needs to print a report of one client.Everything went smooth untill i came across my multiline input text data.When i display it in the PrintPagePreview the text go's outside my page. Even when im printing it only the halve of my text is displayed. I googled and looked everywhere but i can't get a clear fix for it.
[Code]...
I used to program with Visual Basic 6, so I have alot of old programs that I'm updating, plus I'm learning the new VB2008 methods. I'm writing a program that replaces the old "BitBlit" function which is no longer supported by Visual Basic 2008. It involves three picture boxes, one holds the sprite bitmap, a second holds the mask (silhouette) of the sprite bitmap, and a third has a background image.
[Code]...
drawing text on a window which is not the current form's window.I remember doing this in Win32 api with getwindowdc(handle) to obtain a DC for the Window, then textout() on the DC.
View 2 RepliesFollowing code doesnt work and raise error "A parameter is missing. [ Parameter ordinal = 1 ]".What s wrong with it?I am developing pocket pc application in vs 2008 and sqlce 3.5 sp1.
[code]....
I'm Trying to Call the Stored Procedure which has one input Parameter and one output parameter . VB.net code is below
[Code].....