How do I use the IList(Of T).Max function in my example below?
Dim myList as IList(Of Integer)
For x = 1 to 10
myList.add(x)
Next
'Error: 'Max' is not a member of 'System.Collections.Generic.IList(Of Integer)'
MsgBox(myList.Max())
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.
i have to develop API in .Net 4.0 which can be used in VB 6.0,i know how to use this and currently i am using my this API in VB successfully.but Stuck at one place,i have collection class and i have to expose it to VB with having functionality of List class of .Net.[code]i know that generic is not supported in VB, but i think with this declaration in VB 6.0 it creates interface class for class B as IList.but in VB using object creation of class B it doesn't provides me members of LIST in intellesense like (Add,Remove of List Class)
View 2 RepliesHow could I add ObjectCollection items to an IList(Of SomeType)?I have tried with:
For Each obj As SomeType In listBox.Items 'ObjectCollection MyObject.ItProperty.Add(obj) 'IList Next
I am creating a generic class that is Implementing IList(Of T) which requires that I implement the GetEnumorator of both IEnumerable(Of T) and IEnumerable. When looking at the members of IList(Of T) I see only one GetEnumorator function, yet it implements IEnumerable(Of T) and IEnumerable. How can I use one function to implement both interfaces when the function definitions only vary by return type?
View 8 Repliesis it possible to add multiple strings per item in a Ilist?If so can someone point me in the right direction? I've looked on the msdn and can only find examples on how to add one string per item
View 16 RepliesI'm using the Dynamic LINQ library code sample to dynamically return some data. The number of columns I'm returning is variable depending on user input. I'm enumerating the IQueryable into an IList. What I need to do is step through the Ilist one field at a time. I can get one row at a time by iterating through the IList's rows but I can't for the life of me pull one field out of the collection.For example, here I'm returning two columns (hard coded for testing but in prod it will be variable depending on what fields the user chooses):
Dim Dynq = dc.dt _
.Where("RUN_ID = """ & runNumber & """ and Upper_Pressure > 95") _
.OrderBy("Upper_Pressure") _
[code]....
Now I can pull a field out of the Ilist if I know the column name with something like:
something.Run_ID.ToString
but I wont know the columns I'm using until runtime and dynamically inserting it in a variable that's set at runtime doesn't work.So in Summary I have a Ilist that looks something like this
1 | Auto
2 | Auto
3 | Manual
4 | Manual
and I'd like a way to return
1
and then return
Auto
and then
2
etc...
Okay, so I have a Generic IList of custom objects that I want to use as a datasource for a repeater.
Dim productRows As IList(Of MyCustomObject)()
'fill list with data
rptResults.DataSource = productRows
[code]......
i am having trouble displaying the values i get from an IList(Of T) and displaying that in a listbox found on another form. I have used a for loop to get the values from the IList, then i can display that in a msgbox. for eg:
Dim j As Integer
Dim path As String = ""
For j = 0 To best_tour.Count - 1
[code]....
best_tour is ot type IList() path keeps the name found in the list everything works fine inside the loop..but it does not populate the lst_output listbox.I have tried using files, but in vain. It just get the values from the list but does not display that on the listbox.If that can help, then listbox is found in a panel on the form2, but taking it out of the panel does not affect anything.
I have a piece of code that does an action to any collection that implements generic.IList<T>However to do this it needs to get the type <T> of the generic list.e.g. If I pass in a variable of type Generic.List(Form) then in my code I need to get the fact that the list is made of Forms. To add complexity the list may be empty (So you can't just look at Item(0).GetType)
View 6 RepliesI am updating a legacy application, and it was reading a dll from another project for a Dictionary(of Guid, String) of items and using them.
The requirements have changed, and the method that was returning the Dictionary is now returning an IList.
This is the odd behavior of this; the intellisense is not throwing a cast error, nor is the compiler. It does not throw an error until runtime when it tries to set the Dictionary to the IList.
Example:
Dim someDictionary As Dictionary(Of Integer, String) = New Dictionary(Of Integer, String)
Dim someList As IList(Of Integer)
someDictionary = someList
why the compiler is not catching this?
I am declaring an IList:
Dim OrigVendors as IList
OrigVendors = new List( of IVendors)
I populate the OrigVendors variable and what I want to do is find all the objects that have the ID I am looking for. Then I need to update a property on that object for only the ones found. Is this do able with an IList or do I need to use some other type of collection? I am using VB.net.
In a program I am writing (in VB.NET, 2008), I have 2 classes, "Receipt" and "Group", each with similar properties, both implementing a custom interface entitled "IIDUser". In my program, I have a number of lists of "Receipt" and "Group", declared like:Friend receipts as List(Of Receipt)
I have written a few functions that apply equally to managing both lists of receipts and groups, declared like this one:Friend Function getNextAvailableUserLabel(ByRef theList As IList(Of IIDUser), ByVal startLabel As Short) As Short
Then called like this:getNextAvailableUserLabel(receipts, s)
I did all this in an attempt for interface-based polymorphism, as I thought writing 2 identical functions (except for that one would be for lists of receipts while the other for lists of groups) would be bad practice (and waste time). However, I get an "InvalidCastException" during runtime. It is explained, "Unable to cast object of type 'System.Collections.Generic.List`1[Receipt_Sorter_v2.Receipt]' to
[Code]...
I'm new to generics and am having some issues when using with interfaces.I'm developing with VS2008 - .NET 3.5 Ultimately, I'd like to create an interface that inherits the IList(Of T) interface and add a function definition to the derived interface that adds a new element of type T to the list and returns the index of the newly added item.
I have everything figured out but am stuck on a casting issue. If I execute the following line of code at runtime:CType(New clsObjectFactoryList(Of clsIDNamePair), ifObjectFactoryList(Of ifIDNamePair))
I'm reading a binary file into a bindinglist of (t); to be bound to a datagridview.Each line in the file represents a single transaction but I need to consolidate and or filter transactions that meet certain criteriaI know how to do this from a mechanical standpoint (looping the list while adding each item, and adding a new item, or merging the data with an existing item), but I'm looking for a practice, pattern, existing components, or something else that I'm missing (I'm drawing a blank for keywords to search).I don't want to reinvent the wheel if I don't have too. I'm particularly concerned with speed and performance issues with 100k plus records to process in some instances.Currently working with .NET 2.0, but will move to 3.5 if a particularly sexy solution exists.
View 2 RepliesI want to make an numerical integration method with takes in an analytic function and integrate it over a specific interval. For the numerical integration procedure I want to use some procedures in nr.com. The problem is that these are programmed in C++ and they uses functors to pass a function to the integration method. How can I do this in VB 2010?
I want to initialize the function (i.e. set a=1,b=0 for function y(x)=a*x+b) and then pass the function to the integration method. Then when the integration method call the function it only calls the function with one parameter (i.e. x since a,b is already set)
What is the best way to do this in VB2010?I want to make a general integration method where I can pass any single valued function and integration limits.
I have just started using VB, and from what I have found so far it seems like the tools you have is
- to us a delegate for the function
- to use a lambda expression for the function
- send a pointer/adressOf
- to create a function class/structure and submit this to the function
As for now I am most inclined to create a function-class. But I am not really sure how.F.ex. I make different classes for each "uniqe function" I want to integrate, but how can I pass them to the integration function when I need to specify the argument type in the integration-function-call?This seems like a basic problem which applies to many Math operations, so I think it would be very useful to clarify this.
I'm trying to undersatnd the syntax of calling a funciton and it seem confusing when I'm using a web service in ASP.net. Maybe this question should be in an ASP forum, but it is a VB question. This simple web service allows you to type in your name and it response with an alert box with you name.
My question is, How can you call a function with 2 arguments when the function is only defined for one. I understand that the second argument is actually a method that handling the respons, but how can you interchange function arguments for methods and how do you know that there are methods for
Here's my call:
<script type="text/javascript">
function HelloWorld()
{
var yourName = $get('txtYourName').value;
[CODE]...
I am trying to convert a DLL function call which has the Callback function routine called within the DLL function call.The DLL function call signature is like this:
typedef void *HANDLE;
typedef HANDLE HACQDESC;
DECLARE_HANDLE (HWND);
[code]....
how to convert this DLL call to VB.NET and also how to create the callback function and send it as parameter to this function
call.
i wanted to ask how to make picturebox1 ,to which functions are already assigned, perform the same function as picturebox2 ,to which no functions are assigned.For example:I have already made picturebox1 and have assigned it alot of function like when play button is pressed then picturebox1.visible = true and when we press pause button picturebox1.visible = false. So now i decided to make a theme and have to remove the picturebox1 and want to allow the picturebox2 to havefunction of picturebox1.But when i disable the theme the function of picturebox1 should go back to picturebox1.
View 6 RepliesI need to execute a stored function in oracle or sql through vb.net. I created a command object. Depending on the database type(oracle or SQL) i am preparing the Command text as Select functionName(?,?,?,?,?,?,?,?) from dual; (For Oracle) Adding the parameter values of the function. Now performing the ExecuteScalar which is not working saying invalid parameter. This works with ODBC connection string. But ODBC doesn't with 64bit. My Requirement: Code should execute a user defined stored procedure by taking the values at runtime.
View 1 RepliesI'm currently working with a client's VB.Net code, which was developed for them by a small development shop a few years ago and which they purchased and have been maintaining and uprgrading since. This client's primary developer is out on indefinite (likely permanent) medical leave and I'm now filling in until they bring in a full timer (as I'm a contractor here). My current task is to add some functionality to a the VB.Net code they purchased. I'm finding practices and techniques in the code that absolutely baffle me and can't make the code do what I want. I'm starting to wonder if it's me and was hoping to get some thoughts on the code I've encountered.
For example: Setting a variable to accept the result of a function by calling the function with many parameters, clearing the parameters in the function, setting them to some value, calling another function with those new values, then never using the values returned by the functions. I'll add a code snippet in the first comment since this is already getting long.
Hi. what is the difference of sleep function and pause function (using timer) between a loop.
View 12 RepliesWhat does this error mean in VB6? Function or interface marked as restricted, or the function uses an Automation type not supported in Visual Basic.
I keep getting it when i call a particular method of a dll that comes with windows xp and beyond (in system32 called upnp.dll)
How can I call a function from inside another function and suspend the calling function until the called function is finished? I hope I can get some replies because I don't know how to ask the question and make sense:).
Anyway what I am trying to do in steps:
1. The user clicks button1 which triggers the click event.
2. From the click event I call a function
3. I then pop-up a form, that has instructions for the user to read.
4. After the user has read the form he will click the "Done" button and return to the calling function.
The problem is the the calling function continues to execute. I want to stop execution of the calling function until the users clicks the "Done" button on the instruction pop=up. I know I can use a msgbox but the instructions can be lengthly and does not look good in a msgbox.
I have tried the Call method with return in the "Done" button click but I can make that work. I also tried a goto statement but I can get that to work either. In the call statement I said call frmInstruction.show() and it got there but as I said the calling function continued to execute.
ive two custom controls, which are used to draw and edit etc...(like paint but customized....) i want to save their images with a single click....So im using the Getimageofcontrol function to do it....its code is below:::
Public Function GetImageOfControl(ByVal c As Control) As Image
Dim rc As New Rectangle(c.PointToScreen(c.Location), c.Size)
Dim i As Image = New Bitmap(rc.Width, rc.Height)[code].....
and the code to call this function for saving the images is simply.. ...
GetImageOfControl(pboxd).Save("c:78.jpg")
GetImageOfControl2(pboxf).Save("c:lp.jpg")
but the problem is that both the images have the same content....
I have a function where I am performing a lot number of database operations inside a Sub. The operation when called directly like:ExecProcess()
takes about 11 seconds to run.However, if I create a Delegate, and call the sub using BeginInvoke(), the very same process takes over 40 seconds to execute.Here's the threaded code:
Protected del As ProcessDelegate
Protected Delegate Sub ProcessDelegate()
del = New ProcessDelegate(AddressOf SELocal.ExecJob)
Dim cb As New AsyncCallback(AddressOf Me.ExecJobComplete)
del.BeginInvoke(cb, del)
Anyone know what may cause a function to take longer inside a new thread, rather than calling directly?
I have 1 string : abc @#ABC.xyz123ZYX
Now I need to encode the string:
The encoding alphabetic characters,
CODE:
With this string, after encoding, the result is: zyx @#ZYX.cba123ABC
About Function Encrypt and Function Decrypt?
To have a function that takes the average (which is calculated by a different function) say for example the average is 6, now the function is to take the number 6 and get the variance from six to another number lets say its 12 so this will return a calculation of 50% variance. now here comes the issue, i have it calculating the variance how ever lets say that there is a score that is 0, how can i make it calculate the variance without taking count for that 0? i guess you can say i need it to "skip" if its a 0.
View 5 RepliesSome programs implement command parameters, Like my favourite computer game - Crysis - has them and windows media player has them.But how could i implement them in VB.NET..I want to have a component of my program built as a seperate exe - so it can be an Optional component.But of course the seperate exe, on load, needs data passing to it.So i need something like Process.start("Componentname.exe", "/StartDL <Suchandsuchastring>)/StartDL will need to call a function, and the string that it uses will be given to the function to initiate a download?
View 9 RepliesIf a subroutine is called within a function, does the function always wait until that subroutine is completely finished before it will proceed with the rest of the function? If so, is there any way to make it not wait and continue on with the rest of function and not care what happens in the subroutine?
View 3 Replies