Add Extra Values To A WinForms Combo Box Based On A Hashtable?
Aug 6, 2009
I'm trying to add some extra key/value pairs to a combo box using VB.NET. The initial item list is generated from a hashtable, which contains a collection of objects.I've managed to add the extra values to the box using the Add method, however I now run into problems when reading back the selected item from the combo box because some list items are objects, while others are strings.
My best option seems to be to load the initial data as key/value pairs by looping through the hashtable, however this doesn't seem to be working too well either because I'm still getting errors.I'm getting frustrated because it's taking me hours to do something that should take 5 minutes!
I've got some code like the following. I want it so that when I chose an item in 'select 1' it changes the in the second combo box but I'm not sure of the best way to go about it. Does it have to be AJax or can it be done with just Javascript?
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head>
I've been asked to re-write an application that was written sometime ago by another programmer. This application reads data from a database table, massages it, and then writes out the results to a text file that is later shipped off to another company. When I run my new application, it generates a file that, according to the byte count, is twice the size of the file output from the old application. However, to look at the two files with note-pad they look identical. I found that by using 'Ultra-edit' that the new records have a low-value byte hex '00' between each real character.
i have a small program to run through a log file and extract data from it which works, but the array it puts out has a blank value before and after the actual data values, and it confuses me why that happens, i dont really understand why and was hoping someone here knew! the parts of the code related are below
Dim rgxSessionStart As New Regex("^Session Start: [A-Z][a-z][a-z] ([A-Z][a-z][a-z]) (dd) dd:dd:dd (dddd)") Dim substrings() As String substrings = rgxSessionStart.Split(LineIn)
a sample line that it would match is Session Start: Sun Aug 22 00:00:00 2010 which WORKS, but the values of the array are "","Aug","22","2010","". so its not a critical problem because i can still get the data from it, but those blank values are puzzling and i feel like maybe im doing something wrong with the syntax or method for them to be there.
How to bind data from database to combobox of winform in VB.NET .
Database : MSSQL server managemant studio Front End : Vb.net 2008
In the combo box binding,i need to put "Product_gid" in index and "Product_Name" in the value of combo box.How do i add an item "Select" in the 0'th position of Combo box,So that every time i opened the list of combo box,the 1st item will be "Select",other from database.
You have a pseudo-table class and a pseudo-row class. The row is somewhat generic and has no strongly-typed fields. It follows the typical dictionary interface
Dim age As Object = person("Age") 'accessed via default property Item
vs
Dim age As Integer = person.Age 'an actual property typed as an Integer
What's the pattern to use so that we can bind our pseudo table and its rows to a grid or combo box?
Dim rs As New clsResultSet(tblPeople) Dim id As Object = rs(0)("Id") '913 Dim name As Object = rs(0)("Name") 'Ted[code].....
I'm looking for some advice for an application I currently developing. I'll try to keep this as brief as possible so if additional info is need just let me know.I'm developing an Winforms based event tracking system using VB.Net (VS 2008 Pro). The application collects data via serial bar code scanners and stores this data within a MS SQL Express db located on the same Windows XP Pro workstation that the application is installed on. When the application receives the formatted string of data it checks the db table and sends a reply back to the device indicating whether the data is a duplicate. I have written a PortManager class to handle the serial based devices and this functionality is working well.
I have now been asked to incorporate a new type of collection device into the system. The new device is running embedded Linux and uses TCPIP (POE) rather than serial communication. The device manufacture has assured me he can provide a string from the devices integrated scanner in the same format as my serial based devices.
If possible, I would like to utilize the current application and just add the ability to use the TCPIP devices to it. I was thinking it might be possible to just add a new class (similar to my Port Manager class) to handle the TCPIP based devices.I'm really at a loss as to the best way to approach this. I'm just not that familiar with collecting data from a Winforms application using a TCPIP based device.
I am currently working on a multi branch desktop based project using VB.NET 2008. My Admin want to see the list of currently working branches and not working branches. Additionally they want to know how long a branch is not working.
To display the offline branches I first take a ListBox control named lstListBranch and then upon that control I take another ListBox control named lstListTime to display the offline time.
I want to permanently hide the scrollbar for lstListTime control and want to scroll lstListTime when lstListBranch is scrolled.
I am currently stuck in one part of my application. I have two combo boxes that i am having the users select from. The first combo box is simply bound to a datatable. that is working properly. The second one i need to populate off another datatable after sorting out what the first one is requesting. Basically it's choosing a line number on the first box and then selecting the machine associated with that line number.[code]...
In my below forms, the user select a name from the combo box list and enters an amount for the name selected. The user can enter as many entries. Every time the total button is clicked, I would like the total for each person to be display on the labels.
I have a grid containing rows flagged with different priorities. I want to color the high priority rows red, low ones blue, etc. I'd like to set the shade based on a mathmatically calculated gradient rather than arbitrarily assigning colors to specific priorities. How can I extract a single color from a single point along gradient?
Not sure exactly where to begin with this one. i have a screenshot that would make this easier to ask, but I can't figure out how to post it here.
[Code]...
How can I apply/combine both of these so that it will figure the datediff for each row (on a datagridview), figure the appropiate case and then update each annual leave row in the database?
[code]If I wanted to get Part Name for multiple PartIDs from OrderDetails, how would I go about doing this? Would I use two DataTables? I'm confused as I cannot see an efficient way to do this. The only thing that I can think of is to create a DataTable with SQL:[code]and then maybe use a For loop to take each PartID, create another DataTable to find the PartName for that and then give this to a variable. There could be up to 10 PartIDs to search through and I don't want to have variables such as PartID1 PartID2 etc. [code]
I have a very simple windows forms setup. Form1 has a progress bar and a button on it, when clicked the button opens Form2 which also has a button on it that launches Form3. On Form3 is a button which I want to use to raise an event back to Form1.To achieve this can I add an event handler on form1 that will listen for an event of the type raised in form3? Or do I have to pass references to form1 to form2 and then from form2 to form3?
I create a class "Planet" that can be inherited. One of the purposes of inheriting is to create a template with different default property values. Eg:
Public Sub New MyBase.New MyBase.ForeColor = Red
[code]....
Now, to stop the defaults serializing in the InitializeComponent method, there are 2 ways:If I've implemented the properties using the 'DefaultValue' attribute, and made them overridable, the attribute can be overriden with the new value.The problem with this is, there's no way to just make just the attributes overridable, as opposed to the whole property.I could implement every property with protected Reset'PropertyName' and ShouldSerialize'PropertyName' methods. However, this is a bit of a pain in the arse.Is it, generally, an important consideration to ensure that someone who overrides your base class has the ability to change the default values of a property?
I am familiar with getting a selected value from a combo box but what about if you wanted to get all the values from a combo box then store those values in an array or list. The combo box would be data bound to a source and have an ID as the value member. So How would I get all the values from the combo box.
I have two comboboxes in my form (cbAdresse & cbVerwaltung). Choosing the value in the first combo, i get the value from the table into the textbox txtAdID. Now i try to use the value in the txtAdID as the parameter for the SQL command selecting the values from the table (tblVerwaltung). These values must be added to the second combo (cbVerwaltung). So i use the following code for the SQL Compact Client:[code]Using this code i get the following value in my combo cbVerwaltung: "System.Data.DataViewManagerListItemTypeDescriptor".[code]
I have a combo box that is tied to a binding source that loads a list of users from a table. Currently the list of users is a List of String object type. When a user selects one of the users from the drop down, a list is filtered down based on the selection. To do that I currently have to requery the User Table to grab the UserID column of the user selected, which seems a bit inefficient to me.
Is there a way that I can assign a custom object with two properties (UserName, UserID) and have only the User Name is displayed and when I have to filter the list, I already have the UserID, so there is no need to requery the database.
I am working with Vb.net and have a form with a combo Box. On load the form is loaded with one of the following details depending on what is stored in the database; Cancelled, Processed and Failed.
Then I have an update button and when the user drops down the list he/she can select between Cancelled/Processed/Failed. I want to be able to grey out or disable Processed and Failed, so that when the user updates the field he/she can ONLY update with the Cancelled option ONLY.
let me explain further i have table account. in the table are 2 columns namely account_type,Account_name.So on the forms, i want the combo to show the 2 columns even though ony one column would be saved. Am able to do this in access as attached.[code]...
I've used VB to connect to Excel and get the titles of the different columns in a spreadsheet. These then display in a drop down combo box for the user to choose from. I'm getting lots of empty values in my combo box because not all the columns in Excel have titles. How would I go about telling it not to display them?
Excuse the easy question but I've only started learning to code a week ago.
Am using a combo box with no of phone numbers .I want to get the phone no one by one in a variable. Now am using the below code to get the combobox values. But still now am getting the following error message System.Data.DataRowView. Please help me to fix this error. am new for vb.net.[code]
I have A combo box with 5 values in: How would i save all 5 of those values to my file?sw.WriteLine(CustomerIDTextBox.Text + ":" + CustomerFirstNameTextBox.Text + ":" + what????? Once these values are saved how would i go about retreiving them from the file and displaying them back into the Combo box?
