I have a listview control in my form which contains 44 columns. When user clicks on particular node in the 'tree view' it loads corresponding records to the listview. If the number of records is less then it works fine, but if there is more number of records then it takes more time to load(very slow).
View 4 RepliesI have a vb-2008 program that contains a (listview) control.
View = details
AllowColumnReorder = true
Lets say the table has 3 columns (a,b,c) and 1 row of data.
a b c
1 2 3
I want the user to be able to re-arrange the columns (by dragging the column headers) before printing the contents of the table.
c a b
3 1 2
Statements like:
.. ListViewX.Columns(2).Text
.. ListViewX.Columns.Item(2).Text
.. ListViewX.Items(0).SubItems(2).ToString
Give the column-name (c) and cell-contents (3) of the origional table .. not the (3rd) column (b) of the re-arranged table.
How can i get the column-name and cell-contents of the (3rd) column of the re-arranged table?
i am developing a point of sales system. currently i have my product code scanned and displayed in a listview. lets say that i have 5 product codes displayed in my first listview. By clicking on a button, how can i use these codes to call upon the details (prices, product name, etc.) of the corresponding codes and display in another listview?
i am using Visual Basic 2008 and MsAccess as my database. who have the idea on solving my question. (As my last thread has not been answered at all..
i need to do quick selection and adding of large list in listview vb.net 2005, say 100,000. most people have suggested virtualmode, but i will be removing and adding items in these at different times. i thought of using api, as it is somtime faster,
View 8 RepliesWhat 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 am going crazy trying to figure this one out. I have been told many times that you can get the data of a column in a listview in this manner: YourListView.SelectedItems(0).SubItems(1).text This does not work. I have a ListView called EmployeeListView that is correctly populated by my database. There are three columns: (0) is First name, (1) is Last name and (2) is Employee ID. I can see the information in the ListView when I run the program. What I need to do is to pull out the Employee ID and put that into a variable called EmpID.
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VS 2008 how do i access listview data ???
View 2 RepliesI am having some trouble accessing the data in a listview. The data in my listview is popluated from the database which works fine. What I want is the user to be able to click on the entry in the listview and it show them a messagebox with all the data from the listview. I have 1 main item and 2 subitems in the listview.
View 5 RepliesI'm trying to build an app using WPF and I want to display a load of data from some tab delimited log files in a data grid style. I know there is no DGV control for WPF so after watching a few "forms over data" videos on the MSDN site I figured I should be able to do it using a ListView with DataGrid tags within it.So after messing about with the XAML code for a bit I managed to create my column headers in my ListView etc and I can load data into it fine if there's just one column... but obviously I need more than one column.
So I thought fine I just create my extra columns and then use ListViewItem and ListViewSubItem classes to create the content for the listview and then add them to it. However, it seems that ListViewSubItem does not even exist in WPF and the ListViewItem doesnt seem to have any way of editing separate column data. For example, if I set ListViewItem.Content = "some text" and then add that to the ListView it just sets "Some text" in all 5 of the columns I have.All of the examples on MSDN are using data bound listviews and I dont want mine to be data bound I just want to manually load it with items.
My task for the moment is just to find out what the height of ListView's data row is (not the header--different height). The height of a ListView meant to fit exactly the contents of the list can't be set statically. This is because, when a system uses font scaling, the ListView rows are going to be scaled relative to the scaled font. So, I have to find out what the height of the first row is (since they're all the same height) and then multiply that by the number of items in the list. This should get me an exact fit for the height of the ListView.
View 7 Repliesif this question has already been answered many times, but I am new to VB and I don't really understand any of the examples I have found by trying to research this topic. I am using VB 2008 Express Edition. My List View is called listView.
View 4 Replieswhy my code isn't deleting the selected row in my ListView from my SQL table? it says it works fine in run time and removes the seleced row from the ListView but when i restart the program its there again.
Obviously this is because my code isnt actually deleting the data from the SQL table but i cant work out why not? the code for my delete button is as follows
Private Sub btnDeleteTask_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDeleteTask.Click Dim delete As DialogResult = MessageBox.Show("Are you sure you want to delete this customer?", "Delete Customer", MessageBoxButtons.YesNo, MessageBoxIcon.Warning)
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rewriting a class I use for saving Treeview data to a XML file for use of saving ListView data I can't really figure out the rewrite, I'm stucked, unfortunately Listviews seems to be a big problem for me in general.
Option Strict On
''' <summary>
''' The TreeViewDataAccess class allows the nodes within a TreeView to be
''' persisted to xml for later retrevial.
''' </summary>
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I've been searching and searching, but I haven't been able to find a halfway-decent way of adding multiple columns of data into a WPF VB.NET ListView. The data I'm adding is not from a datasource. [code]...
View 1 Repliesi need to use virtual mode in a listview to load data from a table...what to add in the retrievevirtualitem event... i have a data bindingsource which is attached to the table..
View 4 RepliesI have a program that is reading and writing to certain memory addresses to a particular application exe...
So I have a listview control with 4 columns and X rows
| Name | Address | Type | Value |
Name: Is just an identifier so the user knows what it is.Address: Is a specific memory address (eg 0058AFA0).Type: Type of value stored in the address (eg, 4 Bytes, Float).Value: Value to store in the address.Im looking for a way to go through each row, take the address and use this to read the value at that address and then update the value on that row
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I want to write a program to do Markov chain, but my states are quite large. First of all I calculate all the transition probabilities and revenues for all states(1381860 total states), and store in a multidimensional array. Public RevArr(0 To 9, 0 To 750, 0 To 282) As Long
After that the iteration of markov chain should use these as inputs to calculate the steady-state probabilities. But when I try to run the main code I got this error.Exception of type 'System.OutOfMemoryException' was thrown.
The following is the declaration of second array I add just another dimension for storing all the iterations, but I get this error. Dim stateprob(IT + 1, 0 To 9, 0 To 750, 0 To 282) As single
I have a large data.DataTable and some formatting rules to apply.For example, the LASTNAME column has a value of "Jones" but my formatting rule requires it be 10 characters padded with spaces on the right and uppercase only. Like: "JONES "My initial thought is to loop through each row and generate a string. But, I wonder if I could accomplish this more efficiently with a DataView, LINQ or something else.
View 1 RepliesI'm searching the same title "Large amount of data in ComboBox" last 1 and half years but I could not get what I'm expecting! Here is my case, I have 20 thousand unique products, I just fill into dataset & bind only two columns in the combobox for searching & validating the product if it is exist in the product list or not.
1) I read about dataset but all articles are described "Dataset only for few records because it is sitting in-memory". If I fill few records (100 or 1000 products) into the dataset, how can I search & validate REMAINING (NOT FILLED) products?
2) Is there anyother way without filling into dataset and bind to combobox? Can anyone suggest me which is suitable for me?
i want to display a large data in a cell of DataGridView as multiplelines to avoid the horizontalscroll.
View 1 RepliesI am working on a program for a customer and am working in VB2010 in VB language. I have two rather large files that contain data. File #1 is over 300,000 lines of data. File #2 is over 100,000 lines. The files are CSV text files. On a User Form, there are two values, "StartTime" and "StopTime". This is the process I am doing:
1. Read both files into ArrayLists
2. Get item #1 of ArrayList #1 (we'll call this "A")
3. Get item #1 of ArrayList #2 (we'll call this "B")
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I have a large amount of data (400 variables recorded 2 times per second) which is output from a factory monitoring system. It is stored in encrypted files in blocks of one hour from which i can extract to csv with a small piece of software.I would like to upload these csv files into a single database from where i can make graphs, analysis or whatever over longer periods.
The csv files have one line of data per 'time stamp', each of which can be conceptually segregated into approximately 15 individual pieces of equipment.I can quite easily import the data into a single table. However, i find that, very quickly, i end up with an enormous file (about 700mb/month) which is extremely ponderous to work with.
is it possible to split the table into 15 separate tables related by 'time stamp' and second, can each of these separate tables be saved in separate files in storage memory (such that only the files with the desired data are imported into ram).
I'm working on a project at the moment, where all the data being loaded is kept in an XML file which until now have been rather clean with structures such as
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<Textures>
<Texture id="1">TerraingrassDirtNW.png</Texture>
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i am developing a point of sales system. currently i have my product code scanned and displayed in a listview. lets say that i have 5 product codes displayed in my first listview.
By clicking on a button, how can i use these codes to call upon the details (prices, product name, etc.) of the corresponding codes and display in another listview?
i am using Visual Basic 2008 and MsAccess as my database.
I tried to follow this advice, but I still run out of memory.
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Basically, I am reading all the bytes of a 1 gb disk and I want to try and do a md5 hash on it. However, when following this example, my cryptostream gets too large a System out of memory exception.
Is there another way to do the md5 hash over some much data?
I am currently reading it into 10 million bytes arrays at a time. Can I hash the first array, and then use it as a seed for the next array, and so one, like you might do to a CRC32 calculation?
I am trying to show a large amount of data in gridview but the problem is that everytime data increase the gridview row size increase automatically.
View 4 RepliesIs it possible to create a kinda virtual storage in a vb application so that data created during run time are stored right in the applicaion instead of its environment?
View 11 RepliesSome of my users are collecting data files this size and wish to load it in to my tool. Is there a way to load large files of string data w/o getting a OutOfMemoryException? I have tried many different storage methods (Array, List, etc) but always without success.Before anyone asks 'why load it all at once', let me say the nature of my app is speed critical and it must be so.
View 3 RepliesThis is a problem with MS Access, but I can't seem to find an MS Access Forum, so I'm asking it here.I have a large table of just one field. The field type is Byte. I use CTRL C and CTRL V to make a copy of the table.I then compare the Source and Destination tables and lo and behold they are different at about record number 8 million.I also tried an Append Query to append to an empty table (I haven't tried a Make Table query).But, similar corruption.The source and destination tables do not end up the same. The Record where the failure occurs varies, but it is always greater than 8 million.I tried this on MS Access 2002 and 2010 (both with an Access 2002 database).
View 1 RepliesI ran into a problem where the listbox is taking awfully long time to show up. This is not the same in java(It took very very less time - one second max). So, is there any remedy to this??, any other form control??, or some other way?? imports System.Threading imports System.Windows.Forms
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