Item Cannot Be Added To A Read-only Or Fixed-size List?
Jun 11, 2010
I have two datagridviews in my app. They're related. When there is no record in the parent datagridview, I select the "New Row" and then press the Add Button in the child datagridview's bindingnavigator. Then I get that exception:
InvalidOperationException: Item cannot be added to a read-only or fixed-size list.
I know why this happens.When I add new record to child datagridview, parent datagridview's new row loses focus and then delete row. So this error occures.How do I prevent my program from this exception. Remember, it's only occures if there is no record in the parent datagridview.
Now all went well about from using the structure correctly. The working of the structure was perfect. How ever i missed Two important issues. The structure needed a fixed size of 10 items (9 in programming terms starting from 0) And also out of the 5 items allowed to be chosen as one of the member types for the structure a limit of 5 items of that particular type.
I have a label which appears full screen on a projector (VGA 2). In this label I will be sending strings. Some one liner's, some wrapped paragraphs. Some multi-line with carrage returns. My goal is to have the font dynamically change size to be as large as possible without overflowing the fixed label size.
I'm writing code some that is supposed to be creating a list of objects pulled from a data base. The list returned has every item containing the value of the last one added. When I debug the code is VS2008 I can see each time that the list.add is performed every other item in the list being changed to the one just added. Here is the code I running. The line containing ListAKAs.Add(itemAKA) is the one where the entire list of objects is changed to be identical to the one just added.[code]....
I am working on a project for a class, and am having trouble getting my program to automatically calculate the subtotal every time an item is added to the shopping cart list. I've tried sub procedures and functions, but I can't seem to get it to work.
In my application I have a listbox and SelectionMode should be MultiSimple because users need to see which items they selected. In another tab we have another listbox this one should show all the selection users had done in first tab. Private Sub
Private Sub XamMenuItem_DeleteClick(ByVal sender As System.Object, ByVal e As System.EventArgs) Dim selectedRowCount As Integer = Grid.SelectionSettings.SelectedRows.Count If (Grid.Rows.Count >= selectedRowCount) Then While Grid.SelectionSettings.SelectedRows.Count > 0
[Code]...
above code throws me a "Collection was of a fixed size".
I have subclassed a control that would be vastly better if it was a certain size. At first, I thought I could simply set the height and width in the constructor. That would annoy people, as the control would be placed on the form at some size, and the size would then shift when the program starts, but it doesn't work anyways because the control constructor is called before the size properties are applied to it. Is there a way to fix the size of a control at design time? The only controls that I can think of that don't have the ability to be sized are pretty highly specialized.
I am developing, in VB.Net, an application that reads from text files using a FileStream Object. I do not use a StreamReader, since the buffering it does makes it impossible to use Seek.hose text files form a database, with both index and data files. In index files, all fields are fixed-length, which is not the case in data files.I've recently run into a problem. Since some of my files contain accents, the corresponding characters take more that 1 Byte. Therefore, when I seek in the index file, and offset appears the rest of my index file is not read in the right way
I am trying to create and initialize an array of structures of a fixed size. Each struct will be populated when a button is clicked. Here is an example of my struct:
public structure buttonStruct dim x() as Boolean dim y() as Boolean
[code]....
In my form_load function I am declaring the array of structs and:
Dim BtnStruct(15) As ButtonStruct BtnStruct(0).Initialize()
[code]....
Whenever a specific button is clicked, I am trying to collect data and store it in the respective struct and so for example, if button 1 is clicked then I will store the data associated with button 1 into BtnStruct(0). The position of the button is stored in a public variable called BtnNum. If I attempt to store information in the struct inside another function as follows, I receive an error
BtnStruct(BtnNum).x(pos - 1) = temp "btnstruct is not declared. it may not be inaccessible due to its protection level"
I would like to take print on pre-printed stationery where I need to fixed up my data in very particular place. Also the paper size is 10 inch by width and 6 inch by height and it is continuous paper which need to be take print from dot matrix printer.
I need to limit a Textbox and DataGridView to only enter text in the fixed size of the cell/textbox on the screen. So I have limited the cell/textbox so user can not change it size. Both allow multiline and wordwrap. cell/textbox is sized to accept 5 lines of data (wordwrap or enters) This is like an online form.So the text enter will be printed so I can not allow scrolling in the cell/textbox.
How can I stop the scrolling of the text inside the cell/textbox.
Also : if the user Paste into the cell/textbox how to truncate text if larger than display area.
I've a text file which has some data written. Records have Starting character as "#2" and Ending character as "#3" in ASCII respectively and the file includes series of records, but not written as Line by Line. The difficulty I'm having is, to how to transfer those data's into a database. The File comes a 7mb file and looping character by character then noting down the Record Starting Character and Record ending Character, and finally substring them is not feasible as it take more time and makes the computer slower. I would like to know is there any easy way to transfer them?
I'm using vb6 to read lines of txt files, using the code posted in ream.In.Code "Reading a Text file Line by Line". My question is how can I real a line with fixed column width, for example:
The objective is to read each part of the row. In Visual Studio 2010 Beta version the code I present below that is actually working but it doesn't work in VB6.
Using Reader As New Microsoft.VisualBasic.FileIO.TextFieldParser("C:\teste.txt")Reader.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.FixedWidthReader.SetFieldWidths(8, 30, 25, 45, 57)
I have a list box on the form which functions as a copy/paste. When you copy something, it is automatically added to the list box as a "clipboard helper". Here is the problem,however: if the text is more than 1 line, the list box does not show all the text.It ends up looking messy.So getting back to my question, is it possible to make the list box item height for an item depending on the amount of lines that item contains?This is a one line sentence in the list box and should take up one line.This is a multi line sentence in the list box and should take up two lines for item height.
I'm new to VB in Visual Studio 2008 and am just trying out some simple test.I just want to change the Font & Boldness of some text but get the following errorProperty 'Size' is Read onlyI have been browsing the forums and it seems that changing the font size etc isn't as simple as
I need to write an application that does the following, and I figured it was a good opportunity to write my first VB.Net application:
1. Get the list of fixed disks in the computer 2. For each disk, recurse through all its directories and sub-directories looking for filenames that match a given regex (eg. MyFile.d{3}) 3. If found, hash this file to get a unique ID, eg. MD5 (just to check if this file already exists elsewhere) 4. If this file hasn't already been seen elsewhere on the disk, copy it to a central directory
I have been a VB user for quite a long time starting from dos-basic types. But only now I encountered with a quite a newb problem :) I tried to search MSDN for it for about a few days and at the end I have to ask this question here because I could not find anything about it.
From time to time I use functions or subs where one parameter is a word from a defined list.
E.g.
private function my_function(byval THE_PARAM as string) as ..........
where THE_PARAM could be "work", "home", "bus", etc. 5 words all together.
How can I define a function so that when I use it on the text of the program I had a hint not just like "THE_PARAM is a string", but I had a choice of those pre-defined words, so I could choose a word from that list.
I am learning to use TextFieldParser to read a fixed width text data file. It works great. I copied code below. Question: How to stop at the end of each line because I need to add some code?
Using tf As New TextFieldParser(fileName) tf.TextFieldType = FileIO.FieldType.FixedWidth tf.SetFieldWidths(60, 30, 20) //three columns
I am used to C like languages such as C#. I added a list box with a list of names. In the code behind I added the below code. When I run the code I am getting the MessageBox but it will state "UserName favorite color is " but does not show the color. I thought it might be misspelled or non-matching names but this is not the issue due to the names being correct.
Public Class Form1
Private Sub lstData_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lstData.SelectedIndexChanged
when I click the Open button a file is opened and its items are sorted alphabetically. to do this I have doubled the size of my list. However, when I click the button again to reopen the same file, the items will ADD ON to the previous open-file event even though I have this piece of lstListboxTwo.Items.Clear()(the correct thing is to clear the previous items and add the new ones)So I think this has to do with the new size of my list..I think that I have to set the list size back to its normal size when re-clicking on the button.
Public Class frmForm Dim List() As String = {""} Dim count As Integer
Having some issues with creating a simple control in vb.net.
I create a control with a single label in, I don't change anything except the colour of the control and the label and also making the label anchor to the edges ( with a small border around the edge)
When i then build it and add this control to a form. Some of the edges are cut off and it isn't anchored the way it was in the control.[url]...
as you can see in the second image the control has lost its white border at the right and bottom.
