I'm using a DataGrid to display the below custom classes via a BindingSource, I'm trying to figure out a way to save them to a file either by serialization or by some other method. I've tried a lot, but I think it has a hard time serializing because the Account object has the CharacterList object or something. [code]
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I was trying to block the closing of a custom combo box popup window in my custom DataGrid. The popup window comes by pressing F4 or ALT+DOWN keys in my datagrid which is getting closed if I press the down arrow for the first time, after showing the first value in the combo box as selected. Next time onwards, if I press the F4 key and down arrow, I can move to any item in the popup window and select the item using keyboard and in that case, the popup window is not getting closed till I press the ENTER key or selection using the Mouse. Is there any specific reason for this behaviour or something is missing in my code part? [code]...
View 1 RepliesI was trying to block the closing of a custom combo box popup window in my custom DataGrid. The popup window comes by pressing F4 or ALT+DOWN keys which is getting closed if I press the down arrow for the first time after showing the first value in the combo box as selected. Next time onwards, if I press the F4 key and down arrow, I can move to any item in the popup window and select the item using keyboard and in that case, the popup window is not getting closed till I press the ENTER key or selection using the Mouse.
View 13 RepliesWhen I update a record at table [Product] with the integer that stands for [Supplier Name] from joined table [Suppliers], this does not appear in my datagridview. Instead, I have to reload the table to dataset to make it visible. What about datarelation? Is it better that loading a joined table over the dataset? Note that I have never dealed with datarelations before.. How can I make a datagrid column to show "Supplier Name" instead of recordID that represents this supplier?
View 2 RepliesI am trying to update a datagrid joining two tables with a bindingsource. I keep getting the following error: "dynamic sql generation is not supported against multiple base tables." Any ideas on how to fix the problem? Also, I realize that commandbuilder does not work for more than one table.
View 4 RepliesI have a datagridview that is bound to a list object of a custom type via a BindingSource. From everything I've read, I should be able to click the column headers and the rows sort, This doesn't happen for me. Sortmode is set to automatic and the column headers aren't set to be used for selection so it should work.
I know that I could sort progamatticly but that seems a little bit of a waste given that I should just be able to do it by default.
I have a SQL table that contains 2 columns - report names and report category. In my application, I have one listbox that displays these report names. I have several categories for the different reports I have. Is there a way for me to display reports belonging to a particular category in one listbox and then have another listbox for another category? This way, depending on user login, I can selectively disable certain reports from certain users. I was hoping that this can be done during form load and not having to click a button to do any BindingSource.Filter method(). I have command buttons that let me search for a particular report based on user input of either the report name or category using the BindingSource.Filter method(). For my Listbox, I have the DataSource & DisplayMember properties set to Report_NamesBindingSource and ReportName. For one of my tests, I took out these two properties and wrote the ff code -
lstBxReportName.DataSource = "Report_NamesBindingSource"
lstBxReportName.Items.Add(Me.Report_NamesBindingSource.Filter = "ReportCategory = Cath")
lstBxReportName.DisplayMember = "ReportName"
hoping to set these properties programmatically and hopefully filter the dataset based on category but I get an error msg on the first line of code. -[QUOTE]Complex DataBinding accepts as a data source either an IList or an IListSource.[/QUOTE]Obviously, my code is wrong. When I comment out the first line and run it in debug, there is nothing in BindingSource.Filter when I hover my mouse pointer over the second line. So my listbox is empty when I run the program.The filter code below works fine for one listbox but I'd like to have different listboxes for report categories I have.- Me.Report_NamesBindingSource.Filter = "ReportCategory = 'Cath'"But how can I assign this type of filter to a particular listbox.
I have been out of VB.Net way too long, I have a custom class in C# that needs to be converted to VB.Net and would like to know the main differences between them. Certain things in C# I cannot seem to do in Vb.Net with classes such as use: public classname or public [classname](DataTable dt) in VB.net
M[Code]...
I already know how to make really basic custom controls where I can pass in new variables to treenodes because of my custom class, but it's not really working out well for me.I figured out how to read the new values & change them while their in the normal treenode because oddly enough once i've passed in an object from my custom treenode class it worked but I want to know a few things.
1.With my custom class, I can't do things like the following.
MsgBox(
New
TreeNode("Today").IsSelected)
If I replace with CustomTreeNode it doesn't work no matter what I do even working with sub/new it always shows a default value instead of what value is, the most I can think of is because sub isn't returning value, but you can't return value in subs, how are you meant to make lines like that work?
2.Also anyways just for sake of having good intellisense & workings is there a way I can make a class of CustomTreeView that's using my CustomTreeNode's so that I can work on things by code in the EXACT same manor I used to given the name is the same but have my new custom values?Currently im stuck passing any changes using the new type & taking it out I type cast over to the custom type again so i can read the values, but I just want was wondering what I need to do to make it work like a real control would.
Anyways is there any way to over-ride the default control or something instead so I can simply add the new variables in there? I want the same functionality of the normal control just with the added variables so I can work with data pertaining to the nodes of each item in the treenode easier.I already used the Tag value to store some information but it's not like that there are 100 different variables to store information & it's not like anyone wants to store lots of values in 1 variable & parse out the one you need, it's possible but if I can create something good here, I want to use whatever I can make instead of taking my time on working on a more painfully difficult to work with, at least later when I might even need even more variables stored pertaining to each of the items.
I'm studying for the MCTS exam 70-536 and have come across the following question:Given the following Visual Basic code sample, which interface must the custom class MyClass implement?
Dim a As MyClass, b As Boolean
a = 42
' Convert using ToBoolean.
b = Convert.ToBoolean(a)
Console.WriteLine("a = {0}, b = {1}", a.ToString, b.ToString)
Before even looking at the possible answers, I can't get past WHY on earth would we be converting the number 42 to a Boolean value?? I tried this and as I suspected it did NOT compile! Is this a trick question or am I missing something? I realized that in order for the code to work, I would need to implement one of the interfaces shown in the multiple choices. STILL, would there EVER be a purpose for this particular conversion?
inherit from two classes in VB.net?We are developing Custom User Controls that inherits from say System.Web.UI.WebControls.Label. We are planning on implementing a bunch of these controls but they will share mostly the same additional properties. We are hopeful about centralising these properties.I have looked into interfaces but it seems they only 'contract' properties you need to implement.
View 2 RepliesI have a custom collection class. The main member of the class is a List(Of T). I did what this article says: [URl] For some reason though I can only foreach my collection once. The second time it tries it goes out of range because the position does not reset after the first foreach. What am I doing wrong?
[Code]...
how to specify a custom icon for display in the toolbox window when you create your own custom control? Something other than the dreaded "gearbox" icon.
View 2 RepliesI have a Visual Basic .Net 2.0 program. I'm moving the settings from an older settings file, to an app.config program settings file. I'm trying to do this as nicely as possible.
So, I added my setting as shown in this image.
On load I do this:
If My.Settings.databaseConnectionSettings Is Nothing Then
My.Settings.databaseConnectionSettings = New ArrayList()
End If
[Code]....
So, the question is, how do I get that arraylist of my DatabaseConnectionSettings saved to persistent storage? I want to do this in the cleanest way possible. That is, I don't want to have to convert it to a string or save it to a separate file every-time I want to use it. I would like to be able to use the My.Settings accessor method.
I have several different lists I want to call. They all have the same format for the class:
id, value, description, order.
Instead of creating a bunch a classes to return the all of the many lists, I wanted to use generics and just tell it what kind of list to return. However, I can not figure out how to populate the classes.
Here are 2 examples of function in my calling code. This should indicate the type of list and the stored proc used to get the data:
Public Function getTheEyeColors()
Dim glEyeColors As New GenericList
Return glEyeColors.GetALList(Of EyeColor)("GetAllEyeColors")
End Function
[Code] .....
i need some help here, i want a result that shown a total number from student who passed some subjects. Let say there are 8 student who got A in subject chemistry, then the output should display result something like " there are 8 students who got A in chemistry". And also is it possible to combined the result, for example i want the output something like "there are "X" students who got A in chemistry and physics". where "X" is variable (number). it should trigger when winform is loaded. im using bindingsource.filter, but failed. because using bindingsource.filter need the input from user then it produce the output. whereas i want the result shown when the winform is loaded. How can i achieve this.
View 4 RepliesI have a main application and the setup project for the app in a single solution.I have custom classes to detect in sql server 2005 express is installed. if it is not I have classes to install it and create my database.Now I need to call the above classes from my setup project before it installs my actual application on a client pc.
View 2 RepliesAm in the process of architecting a new windows forms application, and I intend to use Visual Basic 2008 and SQL Server Express 2005. This is my first application in .Net and I really want to observe the best OOD & OOP principles to create an application that is easy to maintain and extend (add new functionality). My issue is in regard to databinding on the UI. From experience, what do you guys recommend to use for databinding? Should I return datasets/datatables from my Business Layer and bind these to UI controls or should I return Business Objects and bind these to UI controls? And what are the pros and cons of each approach?
View 1 RepliesI Have just been watching a video on throwing Exceptions. Are you supposed to throw System.Exceptions from within your custom classes. to the calling code, Which other way can they communicate. I have read in several places it is bad practice to throw SystemExeptions.
View 3 RepliesI have written multiple programs in the past that deal with cad data. Points, lines, arcs, etc. For each program I ended up creating slightly different versions of some really base classes like a class that defines a point:
<Serializable()> Public Class Point
Public x As Double = 0
Public y As Double = 0
Public z As Double = 0
End Class
My question is how would I use that class in such a way that it could be in a namespace and imported into any future project that I write?
I have a search form on that will be pulling search template queries from a table in the underlying (an Access db on a share). The search form has a calendar control for filtering by date range, a listbox containing the names of the search templates, a second listbox which lists the fields in the selected template, and then some controls which show/hide themselves depending on which field is selected so that the user can pick a field and enter it's unique criteria in the appropriate control for filtering. Below these controls is a DataGrid, which will obviously display the results.
The problem is how to dynamically "transform" this DataGrid to display the selected search template. These templates do not represent tables in the underlying; rather they represent preconstructed SQL queries (stored in a table) which are essentially SELECT queries with joins and no WHERE clause (so they are the results of multiple tables joined together by their keys).
To be honest, I'm having trouble even generating the LINQ queries to represent these template dynamically, but that's not as important, since I can manually translate the SQL queries into LINQ. This is definitely not the preferred method, as the whole point of putting these templates in a table, rather than code, was to allow for future additions without rebuilding/redistributing the application interface.
I am trying to add datagridview control in my custom control but i failed.I started creating new project[windows custom control library], added datagridview control on it and also added a property naming "DGVMain" which refers to datagridview control.I compiled it.
While testing i find its properties like visible and other working but when i click on columns property it doesn't work. i.e i cannot add/edit columns into the datagridview of my custom control.
Did i miss any steps or do i need to add some more actions?
I have created a class "student" and made an array which contains students.I would not only like to display the array in a datagridview, but the array should also be updated if the user makes changes to one of the students in the datagridview.
I succeeded in showing the array in the dgv: one way is using datasource prop, the other is doing is diagrammatically. However, i can't find out how to let the user edit the array by editing the dgv.
[code] i use this line to fill the datagrid Me.tableTableAdapter.Fill(Me.DDataSet.table)how can i fill the datagrid with a custom query?
View 4 RepliesI am working on a project which lets the user edit the students in a certain group using a datagrid. First I created a class called student and then I created a student-array. Displaying the students in a datagrid works fine. On form-load, I change the datagridview.datasource to the student-array. The datagrid has 20 rows by default (Public dbstudebt(0 To 19) As student). When I edit an existing student everything works fine but when I fill something in in an empty cell and press enter or tab to confirm and add a new student, it just clears the cell and nothing happens. So basically, editing existing studs in the datagrid works fine, making new student doesn't work at all as those cells are always cleared immediately.
View 4 RepliesI have a datagridview (windows forms) that is inside an mdiChild form. The custom format is given by a "for" instance, something like this:
For row As Integer = 0 To .Rows.Count - 1
If .Rows(row).Cells("someNumber").Value = 0 Then
.Rows(row).DefaultCellStyle.BackColor = Color.DarkSeaGreen
End If
Next
So, for every row in the grid that you find, if ther value in the "somenumber" =0 paint the whole row green. Problem is, if I put the form OUTSIDE of the MDIParent - just put frmMyform.show() in my btn that calls the form-, the grid WILL apply the format; If I call it like frmMyform.mdiparent = frmMdi, then frmMyform.show, the grid WILL NOT apply the format.
I was trying to block the closing of a custom combo box popup window in my custom DataGrid. The popup window comes by pressing F4 or ALT+DOWN keys in my datagrid which is getting closed if I press the down arrow for the first time, after showing the first value in the combo box as selected. Next time onwards, if I press the F4 key and down arrow, I can move to any item in the popup window and select the item using keyboard and in that case, the popup window is not getting closed till I press the ENTER key or selection using the Mouse.
View 2 RepliesI am new to VB.NET.I am creating an database windows application in VS2010 and SQL server 2008 express.In one of my form i have a datagrid.My requirement is that i want to display the sum of an column of a DB table and other related data from other tables in the datagrid which is having 4 fields :1. MatNo , 2.Quantity ,3. Opening Stock , 4. Closing Stock Db table1 hav following fields : MatNo , Qty1 Qty1 is the field for which i hav to find the sum against MatNo entered by user.In Db table2 hav again following fields : MatNo , Qty2 Mapping of data to datagrid : 1. MatNo : will contain the Matno entered by user.User can also enter a range of material like from 1000 to 2000.2. Quantity : For each of the material entered calculate sum of QTY1 from Db table1.3. Opening Stock : value in Quantity field of datagrid - value of QTY2 from Db table2 based on some select query )
View 2 RepliesI have tried googling so much that I have given up trying to look. I am trying to display a dataset in a wpf datagrid. After that I am going to need to display the individual column value in textboxes. I can then change the value in those textboxes and pressing, say, a commit button, to commit the changes to a database. Here's the code I have so far.
Dim con As New SqlConnection
Dim dbConnString As String
Dim ds As New DataSet
[code].....
it is possible to display image in data grid?
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