I have a 2 classes, one is Employee, the other is Employees. Basically Employees is a collection of Employee, I have a combo box where the Datasource is Employees.
When the user selects a value from the combo box, How do I get an Employee object from whatever is selected?[code...]
It is an Infragistics combo box by the way.
I have a custom collection which is derived from a base class implementing IEnumerable and IEnumerator, this collection is populated with custom objects.I'm trying to set the datasource on a ComboBox on a WinForm to use the above collection - but when the code is run the ComboBox is always empty.
The code I was using was this:
Private Sub ViewSources_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
' declaration
Dim sourceCollection As SourceCollection
Dim source As Source
[code]....
I have two classes, one nested in the other. [code]Neither "Name" or "ID" are unique between operations and records.I wish to construct a dictionary using LINQ = Dictionary(Of String, Of List(Of Integer), whereby the keys are uniqe examples of Names in my collection and the values are the collective set of distinct IDs that are associated with those names.
View 2 RepliesI have two combo boxesthat use the same collection for their datasource. The data member and value member are also the same properties. When the form loads, and I select an item in one of the combo boxes, the same item is then selected in the other combo box. I want the combo boxes to work separately. Do I need to have two different collections, even though they would have the same data in them?
cboInboardKnife.DataSource = cKnives
cboInboardKnife.DisplayMember =
"Name"
cboInboardKnife.ValueMember =
"ToolID"
cboOutboardKnife.DataSource = cKnives
cboOutboardKnife.DisplayMember =
"Name"
cboOutboardKnife.ValueMember =
"ToolID"
I am trying to refresh my combobox when an item is selected and added the highlighted code as shown below; [code]Items collection cannot be modified when the DataSource property is set.
View 3 RepliesI am customizing a DataGridView control. The DataGridView is supposed to be bound to a collection of some type (be it a List(Of T) or ArrayList or whatever), and the idea is that one can easily determine (at design-time in this case) which properties of the type have to be shown in the grid and which column header name they should get. One can do this using an attribute. For example, if I have a class Person with Name, Age and HairColor and I don't want to show the HairColor property, and want to show the Name property as 'Person', I would use:
vb.net
Public Class Person
<Grid.GridOptions(displayName:="Person", visible:=True)> _
Public Property Name As String
[code]....
I do this during run-time by simply looping through the properties of the bound type (in this case Person), retrieving the GridOptions attribute (if any) and checking the values provided. This works just fine except for one thing: I'm not really sure how to determine the type in the databound collection...
At the moment, I cast the DataSource property to an IList and retrieve the type of the first instance in that list (if any). If there isn't a first instance (the list is empty) then I don't know how to get the type... Often I know that it will be impossible to know the type. If someone is binding an ArrayList for example, then it's impossible to know what kind of items he's going to put in that ArrayList. Even the normal DataGridView cannot show any columns when databound to an empty ArrayList. However, the framework's DataGridView does show the columns when bound to, for example, an empty List(Of Person), or a Person array.
I'm pretty sure that casting the DataSource to an IList is not the correct way as all information about the type of items in that list is then lost. But I'm not sure what else to cast it to... ITypedList? IBindingList? I even considered List(Of T) because that's all I am going to be using, but besides the fact that the grid would then obviously only work for a List(Of T) I still don't know how to do this... I don't know 'T' so I can't cast it to a List(Of T)...
suppose I have a collection of objects of different classes (like controls in a form), and all of their classes have a MyMethod extension method. How do I have the appropriatemethod be called for each object, depending on its type?or example,
For Each ctrl In Me.Controls
'call ctrl real type's MyMethod
Next
[code]....
I have a combobobox on my form, and I use the following code to populate the data from SQL Server:
cbname.DataSource = DSAssetName.Tables(0)
cbname.DisplayMember = "IDWLNAME"
cbname.ValueMember = "FIDWID"
[code].....
I have two tables "Person" and "Alias" in a one to many relationship. I have a DGV for "Person" and want to use a combobox for the Aliases. I also have a textbox and a button for the user to type the alias name and click the button to add the alias name to the combobox and update the dataset. I keep getting the "Items collection cannot be modified when the DataSource property is set." Error. But if i use a DGV instead of a combobox for aliases, I have no errors and everything works fine. If I remove the datasource property for the combobox it will not get populated with the data already entered, so how, or can I, set it up where the combobox gets populated when the form loads and able to add items to the combobox????
View 1 RepliesLike i want it to read the lines i have in the text file but i get an error Each time i press the button Why?
Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
Dim objreader As New System.IO.StreamReader("C:UsersJamesDesktopMusicas.txt")
Do Until objreader.EndOfStream
[code]....
Error:
Quote:
Items collection cannot be modified when the DataSource property is set.
Error line
Quote:
ListBox1.Items.Add(objreader)
I 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]...
I'm still teaching myself how to bind and use observable collection. One problem that I'm a little confused on is binding multiple classes/observable collection to one page. In other words, if I have a PersonName class and a AnimalName class, I have to create two separate observalbe collections for each? How would I set the datacontext when a page only allows one?
[code]...
Now If I add another class, how would I combine the two on the binding part and collection part.
I list folders in my combobox but I'm trying to sort the folders alphabetically and then numerically or vice versa.
My coding to populate my combobox is
With Combobox1.DataSource =
(From folder In New IO.DirectoryInfo("Path").GetDirectories
Select (folder.Name)
).ToArray
End With
Is it possible to sort the combobox?
I have folders that are numbered like 1, 50, 115, 189 etc.
These should display as
1
50
115
189
however they display as
1
115
189
50
I have defined a datagrid which has combobox in one of the columns, is there anyway to modify the datasource of the combobox (the source of the list) at run time?
View 2 RepliesI am trying to get the valuemember of my combobox but it just won't work. I have tried a lot of things (won't post them all here) can somebody just show me how to do this?
Private Sub cmbGroup_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmbGroup.SelectedIndexChanged ' Get valuemember here End Sub
I have a ComboBox that is bound to a List(of T).Now I type-cast the ComboBox.DataSource into List(of T)and add some more elements in the List.The items collection of the ComboBox doesnt get reflected and the new element does not show up in the ComboBox. Am I missing something ?
View 3 RepliesPrivate Sub UsernameEdit_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim sqlconn As New SqlConnection
sqlconn.ConnectionString = "stuff"
[code]....
The combobox just populates with "System.Data.DataRowView" I know it is some command to read the correct data out of the table, is it setting up something like:
dim i as integer
for i = 0 to CompanyNames.length-1
companyadapter.fill(companynames.rows(i)]
next
just curious what happens when i set the datasource of a combobox or datagrid or what-not to a dt then when i want to change what's in the combobox etc., i just set the datasource to a new one. i am cleaning as i go but just want to know what happens to the old datasource:
[Code]...
I have a combobox which i am binding to a sortedDictionary list, so it displays in ascending order. My question is, I need to display "--Select--" as the first option. Is there any way to either:
1) add another item besides for the datasource
or
2) add an unsorted item to the top of the sortedDictionary
I'm trying to use reflection with LINQ on a sub that set datasource of all my ComboBox:
Usual Method:
' ACAmp Panel
cboACPanelAmp.ValueMember = "IDACAmp"
cboACPanelAmp.DisplayMember = "Description"
cboACPanelAmp.DataSource = m_Entities.ACAmps.OrderBy(Function(c As ACAmp) c.SortOrder).ToList
Want to use that sub
FillCbo(cboACPanelAmp, "ACAmp")
Private Sub FillCbo(ByVal cbo As Infragistics.Win.UltraWinEditors.UltraComboEditor, ByVal entityName As String)
cbo.ValueMember = "ID" & entityName
[code]....
I can't figure out the last part of the last line, the LINQ
I have to add item "Final Grade" to my cboQuarter. The thing is, my cboQuarter already has a datasource and I can't add the item "Final Grade" during drop-down. The error says, "cannot modify or insert (can't remember word by word) when it already has a datasource."
View 4 RepliesAppropriate Title would be: Bind comboBox Tag to database.I have a comboBox on form which is bounded but and I need to populate it manually. With some reading on net i have found a way but it is not working
I can populate my combo, select item in combo, update database but the problem is when I load my form it displays empty combo (combo is fulled with my custom data but nothing is selected it must select correct ItemText) and after selecting a value in combo, the value disappears as soon as combo losses focus .
[Code]...
Is it possible to BOTH set a comboboxes datasource AND databind the selected value?Ihave 2 comboboxes on a form that I want to populate with data from 1 table,ut I want the actual selected values on each of the comboboxes to come from separate columns n another datasource Right now if one combobox changes, so does the other if that makes sense.
Here's a sample of code:
'Bind DataSource
With cboYields
[code].....
public Enum ClaimStatus
Ongoing = 0
Completed = 1
[Code]....
With code above, how do I assign the value to the combobox while retrieving data from the table so that it point to the corresponding combobox item. For example, if the value of status_ID is 1 then the combobox should show "completed" in the datagridview.
I am using code similar to this to populate a combobox with items from a database. The display works fine, but when I try to get the combobox.SelectedValue it is returning a DataRowView, where I need an integer. Obviously this is becuase I haven't casted the value to an integer, but the function, CInt(cboPosition.SelectedValue) is throwing an InvalidCastException. Is there any way that I can get the ValueMember's type to be an Integer?
Dim cn As New SqlConnection(CreditDisputesLogConn)
Dim cmd As New SqlCommand("CustomersLookup", cn)
Dim da As New SqlDataAdapter(cmd)
[Code]....
How can I get an item value from a Combobox using a datatable as it's datasource? Here's my code for constructing the combobox. This code works, that's why I'm not showing it all, but I want you to know how I'm creating the combobox.
Try
query = "SELECT category_id, name FROM categories ORDER BY name ASC;"
dbCommand = New MySqlCommand(query, dbConnection)
[Code]....
I want to display what is the item you physically see in the combobox that you select.
I have this controls
ComboBox: list of myobject
TextBox: view a description
DataSource: list(of MyObject)
MyObject:
property id as int
property combodesctription as string
property description as string
What I want: I set the datasource of combobox with list of MyObject when I select a value on combobox, I would like see description in TextBox is it possible bound text property of TextBox to same datasource of combobox or it is possible change description of TextBox only with changedEvent of ComboBox?
I have a ComboBox which is bound with a DataSource from (obviously) a Database. However, there are 659 different entries inside this Database and I was hoping to tack on AutoComplete.
I tried setting the Source to the ListItems since, after initialization and the data is bound, all the items necessary are in fact inside the ComboBox so I had assumed that it would pick that up. I was wrong. I tried using a Custom source but VS errored out saying that I couldn't do that since the ComboBox was bound.
My question is, how can I utilize AutoComplete's "Suggest" mode with a bound ComboBox?
I've gotten to a point where I'm trying to add a ComboBox to a UserControl, and to populate it from a collection which exists in code.
I've been getting along pretty much on monkey-see-monkey-do coding for the most part; copying and adapting existing code in order to get the next stage working, but this DataSource stuff has me stumped. I've been through a whole bunch of articles on MSDN this morning and am no closer to understanding than I was when I started.
Let me go through a few of the things that are messing with me, and hopefully you guys will be able to point me in the right direction:
1) None of the [UserControlName].vb files contains any code. All of the code for the UserControls is stored in [UserControlName]Model.vb files, and then code of the following sort is used:
<UserControl
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:l="clr-namespace:MySolution"
[Code]....
1.5) (using bullet points means I can't use <> brackets or code blocks later on. What the hell, markdown?) Anyway...
2) I'm pretty sure I only want a Static Source for the moment, as the items in the ComboBox aren't going to change during execution, at this time. Problem is, all the articles I can find about this are gigantic, complex things about creating XML readers, and populating DataGridViews and sorting data, and on and on and on. I just want to declare that I'm using a frealing List! A List I've already created in code.
So, yeah, I basically need to use a Public Property ComboBoxLines As List(Of String) from a class which isn't the same class as the UserControl itself as the DataSource for a ComboBox.
I have a bound datagridview which populates from the database using parameters. I've added a combobox column through the datagridview properties. How do I access this combobox column datasource?
View 9 Replies