I have a SortedDictionary of type (String, UserPrincipal). The key is the user's UserID and the item is the user's UserPrincipal object.I have bound the combobox to the dictionary like this
ManagersComboBox.DataSource = New BindingSource(_userdict, Nothing)
ManagersComboBox.DisplayMember = "Value"
[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 have a list of keys and values that I would like sorted by key via a custom Comparer(Of T). I tried using a SortedDictionary, but kept getting incorrect results because it used the comparer to see if the items were the same. For example calling SortedDictionary.ContainsKey() would return false, even though it did contain the key.
When I stepped through the code after calling ContainsKey(), it would go to the comparer.Compare(x, y) function. It would then only compare against a few of the keys in the dicionary, and somehow skip the matching item (which I ensured did exist). I take it that this is some sort of optimization, where some items are skipped depending on what is returned by the comparer.Compare() function? Is it possible to have a dictionary that only uses the comparer for sorting? EDIT: I am using a Type object for the dictionary's key
[Code]....
I'm thinking to use the SortedDictionary to store 65,000 set of keypairs and from time to time during my program execution, I need to retrieve the value from the this dictionary. May i know will there any concern especially in term of speed of execution if i use this method as above? Is there max. capacity that a dictionary can hold?
Previously, i was thinking to use a simple 2D array to do this, but it mights slow things down because in order to retrieve the value, i might need to loop through the whole array till i found the value that i want.
I'm using a SortedDictonary(Of String, String) in my application, and I experience a strange sorting behavior. Consider the following code example:[code]I would expect the keys to be sorted as "'A", "'B", "'C", "A", "B", "C", which is what you get when comparing the keys "by hand", through the < operator. And yet, iterating through the keys returns "A", "'A", "B", "'B", "C", "'C".How can I change the SortedDictionary behavior to sort the words beginning with ' first?
View 3 RepliesI'm having trouble implementing an IComparer method. Essentially, I want to compare the properties of two custom objects (the properties are of type integer).dE is a Dictionary(Of String, customObj)prTabIndex is a property of customObj and is of type Integer (these hold true for all examples)After some more searching I found this thread which suggested 3 things: a List approach, utilizing LINQ, and using some C# 3.0 features. I've tried three different ways:...rolling my own IComparer implementation:
Public m As Sub(ByRef d As Dictionary(of String, customObj))
Dim sortedD As New SortedDictionary(Of String, customObj)(d, myCompare)
End Sub
[code]....
Note that VS2008 has underlined 'dE.ToDictionary...' (to the end of the line) and giving me two messages depending on where I hover my mouse:
1) "Data type(s) of the type parameter(s) in extension method 'signature' As 'signature defined in 'System.Linq.Enumerable cannot be inferred from these arguments. Specifying the data types explicitly might correct this error. Seen while hovering over "ToDictionary".
2) Nested function does not have the same signature as delegate 'signature'. Seen while hovering over anything after "ToDictionary".
Q1) How far off am I in each of the implementations?
Q2) Which one is the computationally least expensive? Why?
Q3) Which one is the computationally most expensive? Why?
I am having issues when trying to populate a combobox that is dependent on another combobox. Populating the first combobox works as expected but attempting to set the value member or display member properties of the first combo box cause its selected index changed event to fire. That event seems to fire before the first combobox is fully loaded. The issue is then raised when trying to populate the second combo box, since it is dependent on having a valid value member to complete the dynamic sql statement, and at that point in time, there is no value member.
I can�t imagine that this is difficult but searching hasn�t yielded me any results. Should I be using a different event? What is the right way to do this?
I have a simple workaround in place - not allowing the second combo box to attempt to populate unless the first combobox has an index greater than zero but this hack is no good since it clearly prevents the user from selecting the first element in the first combo box.
Private Sub SpecialsForm_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim sql As String
Dim dt As New DataTable
[Code].....
When i try to get the selected item for combobox1 drop down, for the AM or PM part, my form wont even start, i think its because i didnt set an initial selected item for this?I have this below, so when i uncomment the part where i get the dropdown value, i cant even start my form, when i just hard code a value it works..
'Get All Current Selected Values
Dim o1_hour = NumericUpDown1.Value.ToString()
Dim o1_mintute = NumericUpDown2.Value.ToString()
[code].....
I have created my first ComboBox form but now I am stumped. I am using VB Express 2010. What Toolbox or Property buttons do I use to generate code for the following:
(1) Title.Text (to add text on my form)
(2) Title. Location (location on the form)
(3) Items.ADD (to add the options on the drop down)
(4) Dropdownstyle
Please give instruction like On ToolBox (left side) click XXXXXX , then click, then click.
I am using a form with a combobox which is populated from an SQL database table. This works OK but is it possible to leave the box blank on the form until a value is selected.By default the box has the content of the first record.
View 4 RepliesI need people to be able to Add items to the ComboBox and then it will save it after adding so when it is reloaded it is still there! I just want it to save to the settings or something. No db or anything.
View 14 RepliesI have my project connected to an Access database, and I was able to sync the data to vb just fine. But on one form, I want to be able to sort through records (there are 15) via the ComboBox. Right now when I select another description from the drop down list, the corresponding data doesn't show on the form with it (the rest of the previous record is stuck there). The Binding Navigator works though. Here is how my form looks:
[Code]...
I use DataGridViewComboBoxColumn, for places one ComboBox into my DataGridView.
Now i want to places 7 more ComboBoxen into my DataGridView, so i have 8 ComboBoxen.
The 8 ComboBoxen are filling from a database tabel, that is "Allergeen1".
Is there a code for this?
[Code]...
i've a question: in a form i've a combobox that inside it are lots of names, and beside it i've a RichTextBox with a text that is generated when i click a button in this same form...using a phrase to examplify the text that i'm talking about, "soccer is the best sport in the world" and inside the combobox i've "soccer/football/golf/tennis" then i would like to know what code i should use to the same text that was generated, substituting only one word, and that word must be the word contained in the corresponding combobox...
example: in RichTextBox i've "soccer is the best sport in the world", then i pick in the combobox the world "tennis", i want a code that after i click the button, transform this phrase to "tennis is the best sport in the world".
how to find item in ComboBox using visual basic 2010 ComboBox binding with Students Table i want to check in ComboBox item (studentName) found or not
View 5 RepliesI have created a database.Now I have created a windows form in which i have added some combo boxes.I want to select the value of the combo box and when ADD is clicked on the form it should be added to the database.In textbox we do Textbox1.text to select the value.What will we do in Combobox .
View 2 RepliesKinda new to working with wpf apps (and vb.net). Looking for a way to filter a datagrid using a combobox (to select the field that the user wishes to search) textbox (to input search terms for specific records). The datagrid loads fine as does the combo containing the fields, however my filter simply does not work.
Code for loading data (works fine)
Dim obj = Me._dataManager.Collections.ReturnCollectionByID(tableSelectionCombo.SelectedItem.TableID)
Me.DataGrid.ItemsSource = obj
obj.Load(New DataManagementDataRequest(Nothing, Nothing))
Code for filtering (not working)
If Me.searchTxt.Text IsNot Nothing Then
obj.filter = selectFieldCombo.SelectedItem.ToString Like searchTxt.Text.ToString
Else
obj.filter = ""
End If
I have a button on a form and 3 comboboxes, each populated with a list. The outcome I'm attempting to programme is, descriptively; Button Click
[Code]...
I'm trying to display some data in my combobox, the strange thing is that the combobox displays all data that has 4 four columns (I only want to display 3 columns out the four) but its not displaying rows that only have three columns?
For example
Text File
Column1, Column2, Column3, Column4
I only want to display columns 1, 3 and 4 so I use the following coding
For Each Line As String In System.IO.File.ReadAllLines(Path)
If String.IsNullOrEmpty(Line) Then Continue For
Dim Columns() As String = Line.Split(New Char() {" "c}, StringSplitOptions.RemoveEmptyEntries)
If Columns.Count < 4 Then Continue For
Combobox1.Items.Add(Columns(0) & " " & Columns(2) & " " & Columns(3))
Next Line
But some of the rows only have
Column1, Column2 and Column3
Again I only want to display column1 and column3.
The below code is a sample code that is supposed to display the months in a combobox.
Dim months() As String = _
{"Select a month...",
"January", "February", "March"}
[code]....
But what am I supposed to do with this code? I have created and named the combobox "cboExpirationMonth", but where do I put this code? I tried to put it as a click event of the combobox, but that doesn't work. I created a button and tried to put the code in the button's click event, but that still doesn't populate the combobox.
Is there any simple way to align the ComboBox text? (Center)If possible, I would like the items in the ComboBox to be aligned also.
View 4 RepliesI am using the following code which populates a combobox with Location Codes from a table called tb_StoreLocations.
Dim SQLStr As String
Dim dtTableData As New DataTable
Dim dbDataAdapter As SqlDataAdapter
[code].....
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?
ATM I'm trying to color individual items on my combobox. While reading stuff I googled, it seems that the only way to do this is through the DrawItem event.My question is, will the draw item be 'called' when i assign text to the combo box? combobox.text = "string"
View 18 RepliesI have some validation set on my combobox and it works as it should, but the problem I have is that the user is unable to click on the exit button, or click on the X to close the form until they have entered a valid field - would it be possible to exclude these controls from the validation? So the user can click on exit, or click on the X?
My coding is:
Private Sub Combobox1_Leave(sender As Object, e As System.EventArgs) Handles Combobox1.Leave
If Not Combobox1.Items.Contains(Combobox1.Text) Then
[CODE]...
I used this
vb
Friend Sub PopulateCB(ByRef mycontrol As ComboBox, _
ByVal expressionSQL As String)
' DMBD is my data-handling class:
[Code].....
Nevertheless, mycontrol remains empty after this.
In this windows forms app, I have a form with six comboboxes. Two are parents, one with a single child and the other with three children. All of these work beautifully except for one of the children. The code for each one is identical, and I've verified the query against the database a dozen times. I even have another of the children that is in the very same block of code. One works beautifully, the other one refuses to populate any data. Below is the code for the one that doesn't work. I would tell you on what line the error occurs, but it doesn't throw any errors. Try catches show nothing, and I have VS 2010 set to throw all errors, but I get nothing, just an empty combo box where there should be a list of names.
Public Class errorTracking_submit
Dim ConnectionString = "Data Source=dvmx6030MS2005_DEV1, 2755; user id =CRCUser;password=TWC5uck5;database=CRCTools;Connection Timeout=5"
[code]....
i think its hard to explain, but here we go.I have a combobox, where you should be able to add item (in this case colors/Hexcode selected from colordialog).So lets say we have 3 items in that combobox:and if you pick blue, the color blue should apper in a background color.I can only get names to work, but i cant find out how to store the hex value data.
View 6 RepliesI'm working with a ComboBox which has 14 items.
Using the following code I got a problem
vb
If Me.ComboBox1.SelectedIndex = 0 Then MsgBox("item 1")ElseIf Me.ComboBox1.SelectedIndex = 1 Then MsgBox("item 2") '...ElseIf Me.ComboBox1.SelectedIndex = 9 Then MsgBox("item 9") ElseIf Me.ComboBox1.SelectedIndex = 10 Then MsgBox("item 10") '...End If
The problem is that after the SelectedIndex = 9 it won't read properly the SelectedIndex = 10, it seems like it consider only the first number (1) instead of the whole one (10). In fact get the same result as if it was SelectedIndex = 1
Can I copy text from a combobox?
Like copy as in I can just paste whatever test I copied from the combobox?