I have a question related with VB.Net Code. I see that the DataTable we can use: DataTable(0)'This return a DataRow with the selected index In the intellisense I see that this functionality can achieve with a extension... but, If I create a extension, always I need refer the Extension before to use it
[Code]...
I have had several occasions recently to access a specific class several times over a relatively small time frame.So I've been storing the value of the class in Session and trying to access it on page load, if it's not available creating a new instance and storing that in session.
So instead of constantly replicating the same code for different classes on different pages I'm trying to create an extension method to do this for me.
[Code]...
I'm stuck on what to do when I make my new instance of my class (it would have to have a New() sub)
I'm not sure where to go from here... or even if this is the best way to do it.
I am looking for a code review on the language extension below which takes a Dictionary object and returns a DataTable representation of the Dictionary object. There are a few demonstrations which work fine so from my view point all works fine but there may have been something I never thought of. look at this extension
Dim Dict As New Dictionary(Of Integer, String)
For x As Integer = 65 To 75
Dict.Add(x, ChrW(x))
[code]....
I have extended an Entity Framework 4 entity class with a calculated property in a partial class. This member is not available on the client to which the entities are exposed via WCF RIA Services.when using C# appears to be changing the extension of the partial class file from .cs to .shared.cs. I tried this with my VB.Net solution (.vb to .shared.vb) and got a long list of errors. I believe what happened is that the partial class lost its association with the entity on the client - it inherited from object rather than EntityObject.
My best guess is that this is related to the way that VB.Net handles namespaces.Each project has a 'Root Namespace' which is prepended to anything that is defined within a code file. C# has a 'Default Namespace'which is the namespace into which new types are placed by default - via a namespace statement within the file.The partial class is probably having the client namespace prepended to it which puts it into a different namespace than the entity with which it is associated on the server.Is there any means of extending an entity in such a way that those extensions are available on the client via WCF RIA Services and VB.Net?
Is it possible to get the row index of a DataTable so that you can access the previous and next row? For example I have a DataTable that contains two columns ChapterTitle and PageURL. This is for a table of contents of a book. ChapterTitle is the chapter name and PageURL is an HTML page that contains the chapter (chaptername.html). When going into one chapter of the book I want to be able to tell which is the next and previous chapter.
After finding the chapter that I'm currently in how can get the next and previous rows?
ChapterTable.Select("PageURL = '" & PageURL& "'")
How can i get the index of an element in datatable which i got using the select method of datatable as
dim d as new datatable= 'some data source'
dim dr() as datarow
dr=dt.select("some condition")
now i want to find the index of first or second item which i have retrieved in data row. i mean there index in data table with out use of loops as loops take a lot of time when there is huge data in data table.
I am wanting to update a datatable which is been created dynamically. Each row has a unique Id column. How can I retreive the row and update a column in it using the Id column
[Code]....
Is this possible to use <Attributes> on a method in a Class extension ?Here is a Class A
Public Class Goblin
Inherits Monster
Enum goblinsRole
[code].....
I know this is old hat, but when you're faced with a problem you cannot solve yourself, you need to find someone with the correct answer.In short, go to the wise.
I am working on an application that has a lot of records, and it uses a listbox control bound to a binding source attached to a table in a data source.A new record with data is added to the binding source's attached table, and, of course, to the underlying sqlServer database table:
[Code]...
I have a data set in the User control . It was working fine but now when I started using another copy of the user control it started showing error DataTable internal index is corrupted: '5'.
dim dv as dataview
dv = new dataview(ds.tables("Names")
dv.rowFilter ="CatNum ='"& val&"'" 'This will always give one row only
dv.item(0)("Names") = myvalue ' here the exception is occurring
I understand that DataTable.Select() returns an array of rows. I just want to know whether these is a way to get the row indexes as well.
View 4 RepliesI have a datatable with 10 records linked to a datagridview. When I initially load the datagridview, row 0 in the datagridview = row 0 in the datatable - based purely on the order they load, and the datatable's default sort order. I then filter my datagridview and am left with 5 records. Is there a way of determining programatically, the actual datatable row number of a row displayed in a datagridview, considering that row 0 in the datagridview is now not necessarily row 0 in the datatable?
View 6 RepliesIn VB.NET or C#, is there a way to determine if a class has been extended with extension methods?
View 3 RepliesI have procedure (Import) that calls a for a new instance of frmImportData. I also have a class name clsBatch that has a data table property called prpParametersTable.For some reason, I get an error (indicated below with ERROR>>>) when trying to assign prpParameterTable to cv_dtImport2. The error states "Object reference not set to an instance of an object.". Why does this error not happen when I assign dtBP to cv_dtImport1? Both cv_dtImport1 and cv_dtImport2 are equal to Nothing and in my Import procedure dtBP = prpParametersTable.
Public Sub Import(ByVal clsB As clsBatch)
Try
Me.cv_clsB = clsB
[code]....
In a DataTable object, is there added overhead to looking up a column value by name thisRow("ColumnA") rather than by the column index thisRow(0)? In which scenarios might this be an issue. I work on a team that has lots of experience writing VB6 code and I noticed that didn't do column lookups by name for DataTable objects or data grids. Even in .NET code, we use a set of integer constants to reference column names in these types of objects. I asked our team lead why this was so, and he mentioned that in VB6, there was a lot of overhead in looking up data by column name rather than by index. Is this still true for .NET?
[Code]...
When i load my database i load it into a DataSet.When i search the database i load the results in to a DataTable.I want to find what index a search result has in the DataSet.When navigating the dataset i can use this code to get the index ds.Tables"Filmer").Rows.IndexOf(ds.Tables ("Filmer"). Rows(inc))But i can't make i get the dataset index of a search result from the DataTable.I thought that i could use the same code when navigating the DataTable, but it only returns.
View 3 RepliesI need to sort a datatable. I do it with linq this an example
Dim query = From c In dt.AsEnumerable _
Order By c.Field(Of DateTime?)("LastPurchaseDate"), _
c.Field(Of String)("LastName") Descending
Dim dv As DataView = query.AsDataView
But my problem is that i need to sort the fields not by passing the name of the column but the index of that.
It seems that my library of extension methods that was written in VB.NET has problems.I have 2 overloaded extension methods Crop().When i reference the lib from a VB.NET project i see them. If reference it from a C# project i can't see them.
View 3 RepliesThe Class Library is an Microsoft Studio extension that generates a file from saving running a custom tool on a template file, following the module from this example I found from Microsoft: [URL]
I can not figure out how I'm gonna debug, build, or deploy this object so I can test it in Microsoft Studio 2010. If you can help me get my class library debugging inside the VSX instance let me know. I will also need to compile and have a delivery method for this extension.
I want to create a extension class for the List type so users can do [code]I've it defined as Type and also tried object but neither are accessible when I have a list of strings.If I set it to be string it then appears..But I want something that is more generic and will work with all lists. How do I need to define it?
View 1 Repliesi have two datragridviewcomboboxcolumn,and two textbox column in a datagridview.each combobox column is binded to separate binding source.
column names are sl_no,col_empname,col_empworktype,Col_Hours etc.and
displaymember,datapropertyname,valuemember and for comboxcolumn are
col_empname:-emp_name,emp_id,emp_id
col_empworktype:-worktypename,worktypeid,worktypeid
[Code]...
IDE is showing error in following code
<Extension()> _
Public Function FindByCode(Of TEntity)(ByRef vTEntities As EntitySet(Of TEntity), ByVal vCode As String) As TEntity
[code].....
I have this one line property
Public ReadOnly Property DateToUniversal(ByVal dt As Nullable(Of Date)) As String
Get
Return If(dt.HasValue, dt.Value.ToString("u").Substring(0, 10), "")
[code].....
1. my program to be the default program for this extension2. when I open the file, I want it to make specific things in the program window3. the things that the file did, I want to be remembered next time I open the program.I want my program to have a better look, so I decided to make Theme Packs for it, and post them on program's website. That's why I want a code for all these things.
View 6 RepliesI have a profile program, were you enter in your personal data such as name, address, phone, company, website, ect, then when you save it, it saves to a file extension like *.pdt, then I can open the file with the extension *.pdt, and all the text fields saved in the *.pdt appear in there correct text fields.
View 2 RepliesI like to create an extension method to Image.FromStream Public Shared Function FromStream(ByVal stream As System.IO.Stream) As System.Drawing.Image
With possibility to cancel processing like Public Shared Function FromStream(ByVal stream As System.IO.Stream, ByVal CloseTask As ManualResetEvent) As System.Drawing.Image
I found out how to create file extensions on my PC and I want to open my program with the file extension, but how would I be able to load the text in the file extension into a textbox on my form if that's what the extension is for? And another question, how could I make a file extension that would act like a folder? Like store images and sound files and things like that.
View 9 RepliesI don't really know how to use compression in VB.net, so I was wondering if someone could explain it to me. I'm also wondering if it is possible to create a compressed file with your own extension.
View 13 RepliesI've been creating short test apps repeatedly to try to understand some of the concepts in VB.NET.For the most part it has been illuminating.I read Bucky's .NET knowlegebase tutorial on passing objects as parameters to newly created forms. He shows how to create a new class that inherits from the base form class and define a New() method with parameters Extending the concept I thought about doing the same thing with a form that was created at design-time (In this case Form2).
[Code]...
I want to read a number of items from a file and then associate each of those items with a new button at run-time, so that when the user clicks one of the buttons I can display some information about that item.Can I use a LIST to manage these buttons and items? Can I create a new class and have each list item of that class, such as 'btnID', 'btnText', etc... ?
View 2 Replies