Updating Listview: Lags At 60+ Entries Being Added?
Jan 21, 2012
The scenario is i get a string sent to me that i split by a space. Any thing under 60 count when the split occurs it's fine. After that i have a problem.Now there is a lot that needs to happen before we can add this newly split array to the listview.First we need to check what the name starts with. Then assign an icon to this nick.When my server class gets sent this string. Raw Numeric 353 channel names i then send it to my nicklist class.
vb
Private Sub InitiateThread(ByVal nicks As String) Handles _server.NameListEventArgs
Dim thread As New Thread(DirectCast(Sub() DoWorkChannelNicks(nicks), ThreadStart))
thread.Start()
End Sub
Then we split the string and loop each item
vb
Private Sub DoWorkChannelNicks(ByVal users As String)
Dim nicks() As String = users.Split(" "c)
When I try and populate a listview with data from an array with 3 entries I find that the data goes into the wrong columns. The array consists of the following.
I have a datagrid view in my vb.net application. I want to update this DataGrid View so it shows any changes to the database (More specifically when a Column is added). I have tried DataGridView1.Update()
when i add the record it saves and returns the save message box as it should and is viewable in the database where it saves to, but it is not viewable in the text boxes when looking back at the form until i close program and re open it, then i can see the record stored in the database, it just wont update the form,[code]
I got the problem on updating the resit number after added the new data.. for the next time i go to the same form, the resit number would not increase automatically but maintain with the same number.. except if i debug my system again,the number will increase..
I have a program where you have three entries, CD name, artist, price and it goes into a listbox and .txt file when closing. I have to have a message box if you enter the same CD name. I have a code to open the .txt file and compare strings but I need to change it to compare only the CD name and not all three entries. Is there a way to do my string compare against my listbox without opening the .txt file?? The program loads the listbox from the .txt file when opening. Private Sub btnAdd_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnAdd.Click' adds CD information to the list box
' declare variables Dim strName As String Dim strArtist As String Dim strPrice As String
So the program I have is an overlay for a bit of software that has a main Video out. Whenever I go between forms the video freezes for a tiny bit but is noticeable. I am using the following to go between forms,
I want to set a certain column to true or false automatically based on what value another column has entered. I managed to get this working by myself using the 'SQL Pane' in VB and testing it by using execute sql but I don't know what to do now. I assumed that I could just save it and it would work from there but that's not the case, it dissapears from the SQL Pane if I close the project (even though it worked fine when I ran the project the first time), so where do I put it/what do I do with it in order to get this to work?
I am trying to add icons to a listview that would contain a list of programs added by the user. I am pulling my hair out over this. I had the solution a few days ago and then I decided to go in another direction and then cleared my browser history. I have searched for that code for awhile now to no avail. First person gets a cookie.
I have a list view with 2 columns (Prodduct and Price). I want the user to be able to add there own values to the listview and have them save so that they will always stay there.I would also like users to be able to delete specific items from the saved list.
The values added to the colums are paired, and must stay together, as one value would be a product and the other a price, So they must, stay together. as a pair
I am writing a basic application to provide remote support to multiple computers over a TCP Stream. For example, if my brother/dad has an issue with their computer, rather than going over to help them I can just use remote support (Yes, I know Windows has Remove Desktop, and their is TeamViewer, ect. But where is the fun in using those =P)Anyway, it basically works by taking a PrintScreen of their computer, sending it to mine and displaying it in a PictureBox, then when I click the image, it records the coordinates of my mouse, sends it to theirs (Little Maths for resolutions and positions ofc) and clicks, then sends a new image.
My problem is, I want a ListView displaying the PC Info, like:
Now, my problem is, I have a Class which does the TCP Server, and in that class when it Receives a Message, it calls the Sub "RunCommand(ByVal Command As String)", which then splits the String and works with it.So, for example, their PC would send the String "Info|DadPC|2GB|235GB|32Bit|2.2GhZ|" And mine would split it, and add that data accordingly.However, what happens is, nothing. If I put in "MsgBox()" anywhere in the Code, it shows it is all Split, and received correctly and everything is fine, but no matter what happens, it wont add to the ListView (Or anywhere else on the form, for example "GUI.Text = Info(1)" Wont work either)?
I'm using the following to check the state of checkboxes and then activate some public subs based on the checked state of the checkboxes:
vb.net Public Sub TestSub() If Me.CheckBox1.InvokeRequired Then Me. CheckBox1.Invoke(New MethodInvoker(AddressOf TestSub)) Else Begin() End If End Sub
Within the Begin sub, I have code that performs specific actions and then updates a ListView with that information.As far as I can tell, the actions are being performed, but the ListView isn't being updated with the info.I'm calling the Test sub from a seperate form, within the BackGroundWorker's DoWork event.Would I have to check the InvokeRequired property of the ListView as well?I'm looking more into the documentation of the BackGroundWorker.
I have a shopping cart ListView control backed by a custom object that has methods for selecting and deleting. In the ListView, one of the columns is an ImageButton that is essentially a delete icon, with the CommandName parameter set to CommandName="Delete".
My issue is related to updating the shopping cart ListView on delete; as the delete method is stored in the custom business entity object, I am having trouble in terms of updating the calculations made inside the cart (we have deleted an item, so I need to recalc shipping, taxes, etc).
What I am trying to do is to instantly apply a filter to a large list of data such that the list is updated almost immediately regardless of the number of items in the list. I have this working using a listview right now but it is far from instant, a list of 5000 items takes over a minute to get through. What I do currently is to maintain a cache of my data that my listview entries are based on. When the user selects a filter I parse this data one item at a time and determine if each item should still be displayed in the listview, if not I remove it. The complexity of determining whether or not a data entry meets the filter requirements is O(1), but just getting through each element in a loop takes significant time, and so does updating the list view graphically at the end of the process.
I have considered using a datagridview instead, using a database connection. I have never done this before and my main question here is whether this would allow me to do what I have described. With the database I could form an SQL query to return only the items that meet the new filter requirements... but would the data in the form update immediately, or would there still be significant delay?
I have designed a form which contains a listview(to see the list records) and textboxes (used for adding or updating).an already save record into table using this
I've made a SCADA system with VB.net and AdvancedHMI, which is a program that monitors plant equipment etc.I've also made an alarm logger which out of a listview, so, when an alarm comes in, say "Alarm 1", en entry gets added to the list view as an "Active" event.
If the alarm clears, then another "Cleared" event gets added to the listview.This works OK, but when you start to get lots of alarms, it's difficult to determine which alarms are actually active, because you may have multiples of the same alarm.What I want to do, is to be able to press a button, which looks for when there has been an "Alarm" event and then a "Cleared" event for the same alarm, and then removes both of them from the listview. So it should then show only active alarms.I know that maybe a listview possibly isn't the best choice for my ultimate goal,
How can I save ALL of the items in a listview, items that were added by the user? I tried application Settings and tried creating a settings file but there is not a settings option for listview items.
I have a program that adds controls on the fly to an auto-scroll panel. When the panel is scrolled (viewing the bottom of the panel for example) and a control is added, it looks like it is added assuming the top left corner of the panel is still at 0,0 when in fact it may be 0,500. To see what I am talking about, create an empty "Windows Forms Application" project and insert the below code into it.
Friend WithEvents Panel1 As System.Windows.Forms.Panel Friend WithEvents btnAdd As System.Windows.Forms.Button Dim ButtonCount As Integer
i have multiple forms in a project and all have statusbar. there is no way to add textbox on status bar but in my previous thread i got the help to add the text box. i created a function in module so that i call that function from all the forms on load and add the textbox on status bar and also add the event on textchange. the function to be called on event change is in individual form (at present)[code]
I have a datatable property called prpParametersTable in a class called clsBatch. I have a procedure that sets a datatable variable called dtP equal to prpParametersTable at the beginning of the procedure. I then add three new columns to dtP.Here is my problem. When I add the three new columns to dtP my original table prpParametersTable also gets those columns added to it, why? I only want to add the three columns to dtP and not prpParametersTable. How can I do that?
Private Function prvfnc_InsertBatchParameters(ByRef cnn As SqlConnection, ByRef trans As SqlTransaction) As String ' set new columns that have BatchID, Insert DateTime, and UserID for the SQLBulkCopy method below Dim clm As DataColumn Dim dtP As DataTable = clsBatch.prpParametersTable
I have a scrollable panel that has a "list" of controlls. However when you scroll, it kinda "lags" with a kinda "motion blur" Does anybody have a solution to my problem?
I have a webpage with a form that is used to edit some object. This object contains a Collection of other objects defined like this: Public Overridable Property Employees As List(Of Employee)
On a form I can delete an employee, add a new one or modify existing one. When I click save new values are sent to the server. On a server I check if the user exists. If exists then I modify its values, if it does not exist then I add it. All employees that exist on the server and were not sent are marked as deleted (State changed to EntityState.Deleted). I try to use the following code (dbCollection = database entities, newCollection = collection sent from the form):
[Code]...
This code does not work, because changing to EntityState.Deleted removes the object from collection, and for each loop breaks, since the collection is modified...I know that I can overcome this problem by using a for loop or adding objects to delete to some other list first, but I hope maybe there is a pattern that would make my code nicer.
I have an app that I'm calling up a 3rd party API.. and on each call I want to store off the patient data in to logs that are like weekly.. so on each call to the API I want to encrypt the data and push as a line into a file..I kinda dont want to open the file.. add in data then encrypt the whole file, that seems like extra work to me.so if I want to encypt the data from string to byte whats the best way to push into a file and then read out.. should I set the string to be a certain lenght so my writes and reads match up ? or is there a way to write to a data file so that it knows the end of the entry ? should I use a type class for this ?
i am using following code to search my computer for files with certian extensions. I currenty searching for .eml files. I need to enter 10 most current files' path to my list box. How can I do it?
Dim DriveLetter As String = "c:" Dim Ext As String = ".eml"
I've made a program for a small business that keeps track of what items there are, their prices, and the quantities of those items. I would like to add a button that goes along the lines of "Add to sale" or "Add to cart", and have it select the currently highlighted item in the database grid view to add the price column up, to make a total for a sale.
