I define a new instance of a forms control collection, but at runtime, the collection is empty. It works for one load button on the form, but not another. The code is exactly the same, but one works, the other doesn't. Here is the relevant code:
Private Sub miFLoad_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles miFLoad.Click
Dim FilePath As String = "C:FListFList.flt"
[Code].....
I am trying to make a collection of controls that I can loop through. So I have this code in my form... Dim WizardFrameCollection As New Control.ControlCollection(Nothing)
I then try to add controls to the collection by I get a error "Object reference not set to an instance of an object." WizardFrameCollection.Add(Me.GroupBox1) I am not sure why I am getting this error. Groupbox1 is a groupbox that is on the form.
I have a DataGridView that has some columns with dates. It binds to an in-memory Datatable which gets loaded from an string array of data passed back from the backend Some of the rows returned have nulls for the date columns. Solution 1: If I define the Date column in the DataTable as "string" I can easily convert those nulls to empty strings and display it in the grid as empty strings (desired results). However, if the user clicks on the date column header to sort by date, it doesn't order the rows as you want. You get a purely string sort order. Not acceptable
[Code]...
This must've have been asked before but I couldn't locate it. In a mixed code project (VB and C#) we were debugging some old Visual Basic code where a statement as follows could be found:
If Request.Params("xxx") <> "" Then
'do something
I considered this a bug as Request.Params could be null, in which case the statement would've become false which wasn't the idea. So I thought. I just found out, -- probably for the tenth time and I will keep forgetting -- that the following two statements are not equal, while Nothing in VB should be equal to null in C# (thought I):
if(String.Empty == null) // always false
If String.Empty = Nothing Then ' always true
Should I dismiss this as a typical Microsoft backward compatibility effort, or should I consider this a huge error in the VB.NET compiler? Does anybody know the Microsoftean opinion on this oddity?
I have created multiple dropdown list at runtime and populated with data. I also have added an eventhandler to determine the selected value of the drop down list.
The code is as follows :
Dim tbl As New Table()
tbl.EnableViewState = "true"
[code].....
I have a Visual Basic 2005 program which runs fine if I execute the built Executable. However if I start the application in VS2005 debugger it gives a weird error
[Code]...
I have a array of strings and I am looping through them, but the string might be empty so I am trying this:
[Code]...
Soemone recently downloaded my software and they got this error: microsoft common languages runtime version 4.0.30319.0 how do i fix this
View 1 RepliesI'm building a data entry interface and have successfully bound the columns that have reference tables for their data using DropDownList so the user selects from the pre-configured values.
My problem now is that I don't want the first value to be selected by default, I need to force the user to select a value from the list to avoid errors where they didn't pick that field and by default a value was assigned.
Is there a more elegant way of doing this than to add code to include an empty value at the top of the list after I get it from the database and before i pass it to the SelectList constructor in my controller class?
I was wondering what is the best way to make sure a date is 'empty' so that, if it hasn't been set by the user, that situation is testable.
I've checked and found one way of approaching the issue:
[Code]....
Is the second one more of a stop-gap measure? Is the first way the sanctioned way (which hopefully doesn't entail a lot of complication with testing/setting the values of the date)?
I have been all over visual basic websites but I cannot find How to empty Recycle bin. I just want a simple button on my Form to "Empty Recycle Bin" and if possible to open Recycle Bin as well with a button.
View 4 RepliesIm trying to add a Xelement to an XElement. But when I tried to add this XElement to the empty XElement VB throws "Object reference not set to an instance of an object" The Bold line code throws the exception
here the sample code: Private Sub Button_OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_OK.Click
[Code]...
[code]......If someone leaves the txt2 empty.... and they click the button how can I pull up another inputbox like for <= 0?
View 3 RepliesI created a button in my form which is used to add a new textbox.But before that, the button should identify if all the textboxes that have been created are empty.If there is an empty one, it would not add a new one.[code]
View 2 RepliesI am having problems with optional parameters, I have declared a method as follows [code] This tells me that the value of "g" cannoy be empty.I put an if statement in there to see what is going on, OrganizationGuid is equal to nothing. How is that possible? I have declared it as a string and gve it value, when when it falls into the method it "is nothing". How can i make sure that it gets value?
View 6 RepliesA really boring question, sorry, but I really don't know that yet ;) I've tryed always string.empty, but with a decimal, there is an error.
View 3 RepliesI need some help with asp.net mvc
Controller:
<HandleError()> _
Public Class HomeController
Inherits System.Web.Mvc.Controller
Function Index() As ActionResult
[Code]...
I have a gridview control that i am manually binding the data in. When i edit a row and update it the values of the text boxes that are sent are always the Old Values. I've found a few threads on this but have not had any luck extracting the new values.
<asp:GridView ID="GridView1" runat="server">
<Columns>
<asp:CommandField ShowEditButton="True" />
[code]....
I've got a new instance of an object in a Linq DBML, but don't know of the test if the a date field is empty.I have tried:
If d Is Nothing OrElse IsDBNull(d) OrElse d <= Date.MinValue Then
TextValue = "nada"
Else
TextValue = FormatDateTime(d)
End If
But the result is "12:00:00 am"
edit: Changed variable name the d
edit: note that the SQL field is nullable
I have a webpage that has a Telerik RadComboBox on the page. One of the properties of this ComboBox is EmptyMessage, which fills the combobox with a message when an item is not selected. I am binding my combobox to a datasource at runtime and for some reason, it wipes this EmptyMessage away. Is there a way to keep my data items in tact and have the empty message there too?
View 5 RepliesI need to give the user an ability to add rows. i can't figure out what control to use to accomplish this. for example
first row with empty text boxes is always visible:
[first name] [last name] [middle name]
add more button
[code]......
How do i check if the dataset is empty? I wrote the following code:
[Code]...
i have a next button that is enabled only after a textbox is filled its working fine but the problem when a user fills the textbox it will be enabled then clears the textbox it will stay enabled and he can proceed how to stop that ?
View 6 RepliesI'm using VB's StringBuilder, and I was curious what is considered "best practice" for emptying the builder/setting it to a new string. Would it be something like this:[code]or is there a "Better" way?
View 2 RepliesI'm working on a program to delete files from a certain folder after they have aged a certain amount of time and either match via regex or extension. I'm running into an issue where files() could be:
files(0) = Nothing
files(1) = Nothing
files(2) = Nothing
etc....
Right now the way it is written, I could place
Else
log(1) = data(1)
log(3) = "Array field empty"
InsertLog(log)
And the program would log as many files as file(i) = Nothing holds. This would create redundant database records and is not wanted. Is there a way to figure out if ALL files(i) = Nothing and then place code in there to insert into the database?
'If log(3) is successful that means no files were old enough or deleted successfully
If log(3) = "Success" And IsArray(files) Then
For Each file In files
If Not file.IsNullOrEmpty(file) Then
'If files is actually something insert into the log
log(1) = file
[Code] .....
Possible Duplicate: In C#, should I use string.Empty or String.Empty or "" ? I just don't understand the benefits of using String.Empty over "". Aside it being strongly typed its longer.
View 2 RepliesSTEP 1: I backup the database using this code snippet (It works fine)
Public Shared Sub BackupDatabase()
Dim sConnect As String = My.Settings.LICConnectionString
Dim dbName As String
[code].....
I'm trying to track down the cause of an annoying interface bug in an app that was ecently upgraded from VS2003 to VS2008 (the bug did not exist pre-migration).What happens is this :1) User clicks in textbox containing a date.2) User clears date3) User tries to move to another field, but can't. No error messages appear - it's as if the validation failed.Further info :1) The textbox's Text property is bound to a dataview which uses a datatable as its source. The bound field is a nullable datetime field with no constraints or default.2) The Validating event fires and the CancelEventArgs property is not set to Cancel. The Validated, LostFocus and Leave events all fire as well, going LostFocus > Leave > Validating3) I can't see any code changes relating to the control or the datasource with a couple of exceptions. The first is that this :
Me.txtRangeEnd.DataBindings.Add(New System.Windows.Forms.Binding("Text", Me.dvClientNos, "RangeEnd"))
has now changed to this :
[code].....
I have a datatable dimensioned as new.I add the columns that I need (during the form's load) I have a datagridview as on object on my form and set the datatable as its source.The table is loaded with values and they display properly.The User closes the form and returns to the 'Main' form. At this point no problems, everything is working great. NOW...The user re-opens the form containing the datagridview It has the values from the previous time it was open, plus the new values ! I have tried several things so when the user goes back into the form it only has the new values, but it always keeps the previous values and appends the new values to it. I have attempted to clear it by adding a line: datatable.rows.clear(); I have activily gone through the datagridview one row at a time and use a statement to clear the cells;
For Each DGVRow As DataGridViewRow In Me.DataGridViewErrorList.Rows
DGVRow.Cells.Clear()
Next
so far no luck.
I have lines like this in my text file
SP-J1-B 203101 Black 99.0 28 0 0
SP-J2-B 203102 Black 99.0 28 0 0
SP-J3-B 20303 Black 99.0 28 0 0
SP-J4-B 20377 Black 99.0 28 0 0
SP-J5-B 203104 Black 99.0 28 0 0
i want to change the value of column two with my own value so i split the string like this
Dim FileContents() As String = IO.File.ReadAllLines("C:\switchoutputA.txt")
For Y As Integer = 0 To FileContents.GetUpperBound(0)
Dim blah() As String = FileContents(Y).Split(New String() {" "},
[Code]....
but some times it dont want to remove empty entries and i get blah(1)="" without any value. how to remove the empty entries?