ScreenUpdating : Manage The Underlying Data?
Jul 14, 2011Is there something like VBA's ScreenUpdating=Off in VB.Net? I mean, I want to manage the underlying data and wish it would not reflect on the screen until the end.
View 7 RepliesIs there something like VBA's ScreenUpdating=Off in VB.Net? I mean, I want to manage the underlying data and wish it would not reflect on the screen until the end.
View 7 RepliesI have a datagrid view in my windows form which is bound to a datatable. one of the column have the status code and i want to display the status description of the same which is defined in an array.can we have display text and value of the column different. i dont want to go with datagridcombobox column.
View 1 RepliesI am retrieving data from my database using a TableAdapter. I was wondering if there is some way I can tell (or be informed) that the data has changed and I therefore need to do another Fill? That way I can just Fill on demand rather than every time the user requests to see the information and I am forced to do a Fill before showing the data because I don't know if is current or not. For the record I am using an ODBC connection string to access a Pervasive PSQL database
EDIT I was thinking I could check the last write time of the MKD file to check if this has changed but this doesn't seem to be reliable as it is not written to until the connection is closed. Does anyone know the circumstances when this is written?
I have an object databound to a WinForm. One property, BOLNumber is bound to a textbox on the form. When you change the value in the form, the underlying BOLNumber property is changed. But the property setter does some "formatting" to the value. I want to BOLNumber textbox to reflect the changes to the value made in the property setter immediately upon the textbox losing focus. I tried implementing the INotifyPropertyChanged interface, but I am either doing something wrong or misunderstanding something it would seem. How do I get the databound control to reflect the changes to the underlying data source?
Public Event PropertyChanged As PropertyChangedEventHandler _
Implements INotifyPropertyChanged.PropertyChanged
Public Property BOLNumber As String
[code]....
I am reading data from an XML file. This local XML file will be updated by another application, and I will need to periodically re-evaluate the XML file, and only import new data into a list box. Furthermore, I want to be able to click on a particular item in the listbox, and display the other values about that particular XML entry.
So, I suppose this is a multi part question. What is the proper way to import only NEW data into the program, what is the proper way to store the data, and how do I associate a value in a listbox with the data stored elsewhere?
I've considered multidimensional arrays, but have been told that strings to char arrays and then back to strings is a terrible way to manage the data, but was never offered an alternative.
I'm developing a forms application with VB2010; and I'd like to be able to freeze the screen / form while the code populates the form for display on the screen. Then unfreeze the screen when the form is populated, to display the populated screen text; in a similar way to the VBA commands Application.ScreenUpdating = False and then Application.ScreenUpdating = True.
View 2 Repliesi've been stuck on this for a while and searched many forums first with no solution so i'm posting myself. In VB for excel i've used Screenupdating= false to disable the screen updating however now i'm creating a visual studio 2010 windows forms application and its not showing up as a property. [code] And i get the error 'screenupdating is not a member of 'system.windows.forms.application'.
View 2 Replies.NET developing and have a simple question, i've been stuck on this for a while and searched many forums first with no solution so i'm posting myself. In VB for excel i've used Screenupdating=false to disable the screen updating however now i'm creating a visual studio 2010 windows forms application and its not showing up as a property. Here's the code i've tried.
[Code]...
I have a program that opens a FormReportViewer. I get an error when I close my program...COM object that has been separated from its underlying RCW cannot be used.
View 2 RepliesI'm designing an ATM where I have to allow a user to "insert" his card and then conduct transactions. After the first user is done, without closing the application, another user should be able to use the ATM. However, whenever I try to log the second user in, I get the following error: COM object that has been separated from its underlying RCW cannot be used.
My code for the opening screen is as follows:
Imports System.Data.OleDb
Public Class StartScreen
'Form-wide variables
[code]....
I'm trying to show a modal form below my text how can I set form position?
View 1 RepliesI need to force a DataGridView cell to update the underlying DataTable.I fill a DataTable using my adapters Fill method, then set that DataTable as my DataGridView's datasource. Lets say one of my DataGridView columns is a CheckBox column.If I left-click a checkbox in the first row and then left click a different row in the DataGridView the underlying DataTable_RowChanged event fires, which tells me the first edit I did has gone to the underlying DataTable.If I left-click the checkbox in a row and then right-click the column header to display my context menu the DataTable_ RowChanged event doesn't fire because the DataGridView row is still in edit mode.I've tried Me.DataGridView.EndEdit(),but that doesn't cause my RowChanged event to fire,I need to ensure my underlying DataTable matches the data in the DataGridView, because I am getting a subset of my original table.[code]
View 5 RepliesI've got a databound query in my application which is querying the "Customers" table in our database.I've created this directly from the ComboBox's datasource creator in the Design view.Various bits of code created in the designer include:
Me.CustomerBindingSource.DataSource = Me.CustomerDataSet
Me.ComboBox_Customers.DataSource = Me.CustomerBindingSource
What I've done in the first stage of developing this feature is to show my users a ComboBox showing a specific subset of the customer list by applying a filter to the BindingSource.
Me.CustomerBindingSource.Filter = "someColumn = 3"
What I want to do on a second pass is to allow the users to type a specific bit of information into a textbox and check whether it appears in Me.CustomerDataSet like so:
Dim x As IEnumerable(Of CustomerDataSet.customerRow) = From cust In Me.CustomerDataSet.customer Where cust.custno.Trim = "test"
If x.Count <> 0 Then
At this point, I have a customerRow object. I want to check whether this customerRow object appears in the list presented to users in Me.ComboBox_Customers via the filtered Me.CustomerBindingSource. Me.CustomerBindingSource does not (directly) contain customerRow objects, it contains Object objects.How do I find out whether Me.CustomerBindingSource contains the customerRow object at whatever lower level?Also Once I've determined that Me.CustomerBindingSource contains the item, how do I select that entry in the ComboBox?
I have a button on the page and a gridview with checkboxes on the first column. The gridview is bound to a List. On buttonClick, I need to retrieve the underlying bound data item (MyEntity) for each selected row. How can I do this? I can't simply recreate MyEntity based on the gridview columns, because I am not displaying all the fields of MyEntity. I need a way to get a hold of MyEntity based on the key (MyEntityId).
View 2 RepliesI've written a custom class MyClass and marked it with the <Serializable()> attribute. I have a set of binary files on my hard drive that I've serialized using BinaryFormatter that came from instances of MyClass.
I've recently changed the structure of MyClass slightly (added some properties, deleted some properties, changed a few methods, etc).
What happens when I try to deserialize the existing objects to this changed class using the code below? I've tried it and not had an error thrown or anything - but surely it can't deserialize properly when the class has changed? Is there a way I can get some useful information out of the serialized files even though I've updated the class?
Here's the code I'm using to do the serialization:
Public Sub serializeObject(ByVal obj As Object, ByVal outFilename As String)
Dim fStream As FileStream
Try
[Code]....
I'm looking for a simple example in VB2008 code.I have the Northwind DB installed on one of our SQL servers.
I've worked with the Datagridview on serveral occasions but never used its update,delete or add functions. I've Googled around the web, but could not find a simple example.
Whats the best way to do this and implement it using LINQ?
find the underlying DataGridView (DGV) when responding to a Right Click on a ToolStripMenu (TSM).I have several DGV's all using the same ContextMenuStrip (CMS) [DGV.ContextMenuStrip=CMS]I have six ToolStripMenuItems under the CMS. I thought I could just add a unique handler for each of the ToolStripMenuItems and be a happy camper on each Right Click...But I cannot figure a way to decode the underlying DGV. There doesn't seem to be any relationships between DGV and TSM and none between CMS and TSM.Is this path a dead end? If so how should one do it? FYI my DGV data is unbounded.
View 7 RepliesI have a Windows Form application with a form that has an underlying data set. When the users click a particular button, the code clears some fields on the form but also is suppose to update a value in the underlying dataset on a field that is NOT displayed on the form.
In VB6 and VBA this is very easy to do. I simply says Forms!formname!NameOfUnderlyingFieldNotshown and pass it the value. How do I do this in VB.net with a Windows Form and underlying dataset?
Re DataGridView Sorry don't really have any code - just a whole project. Basically I changed the underlying Access (accdb) Table by adding a new field, The new field shows up in the DataSources section of the Solution Explorer and in the "Edit DataSet with wizard" page but when I attach the binding source to a datagrid view, the new field is not there. I also created a new bindingsource but still not there.I just noticed I've another table where I changed the names to something more meaningful, and the old names are still there and the data for those fields doesn't display in the DataGridView
View 2 RepliesI'm currently working with a gridview that has a huge underlying dataset.I'm almost certain that I saw something about a new facility in Visual Studio 2010/.NET 4, which would improve the performance (e.g. doesn't download all the data on databind, but rather only what data required for current page). My guess would be that it was using AJAX.I didn't need it at the time I saw it, and now I can't find it, even though I've been hunting online for a while.
View 2 RepliesWhen I call the restful service with the following code, I am getting the error
[Code]...
The above is more or less the complete question. I have created a table in the VB 2010 Database Explorer but I cannot for the life of me work out how I can get this copied or created into the underlying server. It is not appearing in the underyling serverand when I run the code of course I ge "invalid object <tablename>" I have data as well in the table that appears in Database Explorer. I think I have missed something fundamental in my overall conception of using VB 2010 Express with SQL Server Express in that I don't know if I have a local copy (that isn't then mirrored on the server), or what (the ____ have I got)? An article that explains the overall relation of Database Explorer to the underyling Server would be great as well
View 8 RepliesI'm creating a program (Which will eventually be a service) which loops a section of code which downloads files from a variety of FTP servers.All files are succesfully downloaded on the first iteration, however after this the download fails with the following error..."The underlying connection was closed: An unexpected error occurred on a receive."Curiously, the error does not occur if the loop only downloads the same file from the same Ftp server. It only occurs when 2 or more files are downloaded.I use the following code...
Dim fwr As FtpWebRequest = CType(FtpWebRequest.Create(Supplier.FTP_Address & Supplier.FilePath & Supplier.FromFile), FtpWebRequest)
'Set credentials
fwr.Credentials = New NetworkCredential(Supplier.Username, Supplier.Password)
[code]....
I am trying to create a form which will be fed by an underlying database to create multiple form fields for each entry in an underlying database table. This is for a program to monitor patients under anesthesia, and prior to surgery, the doctor will choose which monitors they will be using. Then, on the actual monitor screen which will pop up every X minutes, there will be a text box and a check box for each chosen monitor. I am relatively new to VB, so I have tried to illustrate what I am needing but using the logic that I know from my previous life in PHP.
I am using DevExpress's layout control to place the form fields, so that is the code in the middle of the first loop (on_load), and I know that part works, I just need to know how to name the fields and then recover those fields and commit the values to the database. (the text boxes are added to the database, the check boxes are used to determine if an entry is made for that monitor- i.e. at the end of surgery if a monitor is turned off). I know that my syntax for naming the fields is no where close to correct, and it probably would not work in PHP, but I remember doing something like this in a PHP application I built long ago. [Code]
I have a total of 102 values associated with a fieldname called ArrivedFlag.Then I have a TextBox control with an id of txtFlag on the markup page.In my codebehind, I have an if statement that says:
If txtFlag <> "value1" and txtFlag <> "another value" Then
lblMessage.Text ="You don't have the ability to view details"
end if
This works fine.However, given that there are 102 values, I feel that doing an IF statement 102 times is a bit inefficient.
Dim allowedFlags = New List(Of String)()
With { _
"value1", _
"another value"
[code]....
I was asked by a client to create a tool that would let a user add/modify/delete/read content from a database. The content can be read from TextBoxes.
My question is, what is the best way to manage GUI locks/unlocks for the different states of the program. IE: If I'm in a "insert" mode, some GUI elements should be enabled, and some not. If I'm in the "read-only" mode, a bunch of them should be disabled... etc.
I am writing a program that uses an array with three columns and a varying amount of rows. I need to load info on a list of files in an archive(specifically: file name, size, path), and I am wondering what the most convenient way to store strings(to be loaded into the array) is.
For example: I tried creating a new .resx file in my project, and writing a function to be executed on form1_load that reads the strings from the .resx file and places them in the array in their correct column, but unfortunately had no success.
I really have no idea how resx files work, I can put strings in them using the resource editor, but I don't know how to retrieve them using resourcemanager.
I would just put the info straight into an array, but it's much easier to update a .resx file when the archive changes than it is to update the code.
Could someone please tell me how to use .resx files in vb.net? Or an easier way of accomplishing my goal?
I can't manage to add different values together...
TextBoxAnswer.Text = TextBox1.Text + TextBox2.Text + TextBox3.Text + TextBox4.Text
I import decimal values from my SQL Server into the TextBoxes 1-4, which works fine. But when I try to add the values together into another textbox the answer is just the values combined like a string...?The column of the table in the SQL server has a datatype decimal(18, 2)I have also tried to convert the values in the textboxes into int, str, double... Nothing seems to work...
Example:
Answer = 2,50 + 2,50 + 5,50 + 4,50
So,
TextBoxAnswer.Text = 10,00
but, all I get is:
2,502,505,504,50
I am now convinced there is no such thing using VB 2010 Express. I have read, re-read, studied, copied and pasted code to no end and all I get are error messages galore. It appears there is a big gap between what's on line as far as tutorials and the code that VB 2010 Express will accept. I hate to sound so lost but at the moment I am. I used to program in BASIC and QBASIC. I was a master at opening up ascii text files, reading them in sequential order, sorting, manipulating, then re-writing them. It was all so easy, like this: [code] That's all I want to learn how to do for the moment. But every tutorial or article I find goes off in to wild tangents about How to Manage Directories or it reads the entire text file into one giant object. Or worse, there's some code which looks promising but it won't run under VB 2010 Express or it might run but the author leaves out important parts of the code that have to be declared ahead of the subroutine....you all know what I mean. It can't be this difficult to just read a text file one line at a time, therefore it shouldn't be so difficult to find an accurate and up to date article on this.This is for really rough programming. I don't need an interface of any kind. The user, will not even need to know that anything is happening. I simply want to read text files, manipulate what's in them and then re-write the edited text.
View 5 Repliesim using dreamweaver and i have a table in which i have an image. When i add another table under the table existing it comes right at the bottom. What should i do to that table so i can move it and place it anywhere around the page. displaying my data wherever i want. And another problem is that, when i place something on the top it doesnt show up there it comes slighty away from where i had placed.
View 1 Replies