I'm trying to create an expiration date using values selected from drop down lists on my web form, however I am unable to concatenate the Month variable value and Year variable value. I get the error: Error Operator '&' is not defined for types 'String' and System.Web.UI.WebControls.ListItem'. I have tried to use the "+" also but get the same error.
Here is the code I have:
Dim Month = monthDropDownList.SelectedValue
Dim Year = yearDropDownList.SelectedItem
Dim MonthYear = Month & Year
Dim ExpirationDate As Date = MonthYear
Any help would be greatly appreciated.
You don't want SelectedItem. You want SelectedValue. You should also explicitly declare your variables. You also can't create a Date in this manner. You need to use integers.
Dim Month As Integer= Convert.ToInt32(monthDropDownList.SelectedValue)
Dim Year as Integer = Convert.ToInt32(yearDropDownList.SelectedValue)
Dim ExpirationDate As Date = New Date(Year, Month, 1)
As a slight "cleaner" way to do this I would use:
Dim Month as Integer
Dim Year As Integer
Dim ExpirationDate As Date
Integer.TryParse(monthDropDownList.SelectedValue, Month)
Integer.TryParse(yearDropDownList.SelectedValue, Year)
If (Month > 0 AndAlso Year > 0) Then
ExpirationDate = New Date(Year, Month, 1)
End If
Related
Good afternoon, I'm new to programming and I'm working with VB.NET.
I need to get the difference between two dates and then list all the intermediate dates in listbox1. I tried the following code but it doesn't work.
Private Sub breaks()
Dim date1 As Date = DateTimePicker1.Value.ToString("dd/MM/yyyy")
Dim date2 As Date = DateTimePicker2.Value.ToString("dd/MM/yyyy")
While date1 <= date2
Dim result = date1
ListBox1.Items.Add(result)
Dim term = 1
date1 = DateTimePicker1.Value.AddDays(term)
End While
End Sub
The function is called within a button. When executed it only shows the sidebars but is blank.
The image shows start date 03/10/2020 and end date 03/16/2020, however the result (listbox) does not return anything.
I expected my result to come:
03/10/2020
03/11/2020
03/12/2020
03/14/2020
03/15/2020
03/16/2020
the interval between them.
Can anyone tell me what's wrong?
You can use some linq for a simple solution
ListBox1.DataSource =
Enumerable.Range(0, 2 + DateTimePicker2.Value.Subtract(DateTimePicker1.Value).Days).
Select(Function(offset) DateTimePicker1.Value.AddDays(offset)).
ToList()
It generates a list of numbers to act as the offset from the initial date, then adds them the specified number of times (different between the dates in days) to create all the dates. No loop required.
Credit to this answer
Edit:
This can also be similarly applied to a DataGridView, but in order to make a single column, we would need to select an anonymous type.
DataGridView1.DataSource =
Enumerable.Range(0, 2 + DateTimePicker2.Value.Subtract(DateTimePicker1.Value).Days).
Select(Function(offset) New With {.Date = DateTimePicker1.Value.AddDays(offset)}).
ToList()
You should avoid using strings for datetimes until they need to be text.
The variable date1 can be used for all the dates, like this:
Dim date1 As Date = DateTimePicker1.Value
Dim date2 As Date = DateTimePicker2.Value
While date1 <= date2
ListBox1.Items.Add(date1.ToString("MM/dd/yyyy"))
Dim term = 1
date1 = date1.AddDays(term)
End While
Also, you should make sure to set Option Strict On as the default for new projects, and set it for the current project.
I have one excel page and I store date type datas. This datas extra workdays and plus holidays in every year. Other table in this page has start and end date. I would like to show some interval the employees work days. I would like to use the VBA. How to solved this problem?
Use NETWORKDAYS.INTL()
=NETWORKDAYS.INTL(E2,F2,1,A2:A3)
This pictures the Excel table and my code:
Dim startDate As Date
Dim endDate As Date
Dim retValue As Integer
Dim days As Variant
Dim dates As Variant
days = Worksheets("Tényleges munkanapok").ListObjects("TáblázatKorrekciósNapok").DataBodyRange.Value
dates = Worksheets("Tényleges munkanapok").ListObjects("TáblázatSzámoló").DataBodyRange.Value
Dim i As Integer
Dim actualDate As Date
startDate = days(1, 1)
actualDate = dates(1, 1)
Dim CountVariant As Integer
CountVariant = UBound(days)
i = 0
Do While i <= CountVariant
If startDate < actualDate Then
i = i + 1
End If
Loop
I want to get the last day of the month.
This is my code. If I want to debug it and compile it to the database it says it has an error in the syntax.
Public Function GetNowLast() As Date
Dim asdfh As Date
asdfh = DateValue("1." _
& IIf(Month(Date) + 1) > 12, Month(Date) + 1 - 12, Month(Date) + 1) _
&"."&IIf(Month(Date)+1)>12 , Year(Date)+1,Year(Date))
asdf = DateAdd("d", -1, asdf)
GetNowLast = asdf
End Function
GD Linuxman,
Let's focus on obtaining the result...:-)
See also: here
The comment by #Scott Craner is spot on ! Though strictly speaking there is no need to use the formatting. (Assuming you want to work with the 'Date' object)
To achieve what you want, setup the function as per below:
Function GetNowLast() as Date
dYear = Year(Now)
dMonth = Month(Now)
getDate = DateSerial(dYear, dMonth + 1, 0)
GetNowLast = getDate
End Function
You can call the function in your code as:
Sub findLastDayOfMonth()
lastDay = GetNowLast()
End Sub
Alternatively, and neater is likely:
Function GetNowLast(inputDate as Date) as Date
dYear = Year(inputDate)
dMonth = Month(inputDate)
getDate = DateSerial(dYear, dMonth + 1, 0)
GetNowLast = getDate
End Function
You can call that function and pass it an input parameter.
Sub findLastDayOfMonth()
lastDay = GetNowLast(Now()) 'Or any other date you would like to know the last day of the month of.
End Sub
See also this neat solution by #KekuSemau
Sub Worksheet_SelectionChange(ByVal Target As Range)
Dim d1 As String
Set Rng = Range("A2")
d1 = Range("a2").Value2 'put a date in A2 Formatted as date(cell format)
Dim years
Dim months
Dim end_month
years = year(d1)
months = month(d1)
end_month = Day(DateSerial(years, months + 1, 1 - 1)) 'add one month and subtract one day from the first day of that month
MsgBox CStr(end_month), vbOKOnly, "Last day of the month"
End Sub
I realize this is a bit late into the conversation, but there is an already available worksheet function that gives the end of month date, EoMonth().
Pasting into the Immediate Window:
?Format(CDate(WorksheetFunction.EoMonth(Date, 0)), "dd")
Will return the last day of the month based on current date.
As a UDF, it makes sense to give it a default Argument:
Function LastDay(Optional DateUsed As Date) As String
If DateUsed = Null Then DateUsed = Date
LastDay = Format(CDate(WorksheetFunction.EoMonth(DateUsed, 0)), "dd")
Debug.Print LastDay
End Function
If you feed it Arguments, be sure that they are Date Literals (i.e. Enclosed with #s)
LastDay(#3/10#)
Result: 31
LastDay #2/11/2012#
Result: 29 '(A leap Year)
Note the output Data Type is String (not Date) and that the format of the date can be adjusted as needed (Ex: "mm/dd/yyyy" instead of "dd").
If the Date Data Type is needed, use:
Function LastDay(Optional DateUsed As Date) As Date
If DateUsed = 0 Then DateUsed = Date
LastDay = WorksheetFunction.EoMonth(DateUsed, 0)
Debug.Print CDate(LastDay)
End Function
I hope that helps someone.
In short, a great and straightforward approach is to find the first day of the following month and then move backward one day.
Make yourself a little function that does something like this:
Obtain the month and year in question (the one where you want the last day)
Use DateSerial to combine the month and the year, along with the day "1" to get the first day of the month in question.
Use DateAdd to add one month. This will get you the first day of the next month (which is one day after the date you really want).
Use DateAdd again to subtract (move back) one day. This will give you the last day of the month where you started.
Function eom(ByVal input_date As Date) As Date
' take the first day of the month from the input date, add one month,
' then back up one day
eom = DateAdd("d", -1, DateAdd("m", 1, DateSerial(Year(input_date), Month(input_date), 1)))
End Function
In Access VBA, you can call Excel's EOMonth worksheet function (or almost any of Excel's worksheet methods) is by binding to an Excel application object and a WorksheetFunction object, which can be accomplished in a few ways.
Calling Excel functions with an Late Bound object
The shortest method from Access VBA is with a single line of code using a late-bound object. This example returns the date of the last day of the current month:
MsgBox CreateObject("Excel.Application").WorksheetFunction.EOMonth(Now(), 0)
A more verbose method, as a function:
Function eoMonth_LateBound(dt As Date) As Date
Dim xl As Object
Set xl = CreateObject("Excel.Application")
eoMonth_LateBound = xl.WorksheetFunction.eomonth(dt, 0)
Set xl = Nothing
End Function
An issue with late-bound references is that VBA takes a second to bind the object each time the function is called. This can be avoided by using early binding.
Calling Excel functions with an Early Bound object
If the function is to be used repeatedly, it's more efficient to go with Early Binding and retain the object between calls, for example:
Go Tools > References and add a reference to "Microsoft Excel x.xx Object Library" (use whatever the newest version number is that you have installed).
Add this code in a new module:
Option Compare Database
Option Explicit
Dim xl As Excel.Application
Function eoMonth_EarlyBound(dt As Date) As Date
If xl Is Nothing Then Set xl = New Excel.Application
eoMonth_EarlyBound = xl.WorksheetFunction.eomonth(dt, 0)
End Function
Sub demo()
MsgBox eoMonth_EarlyBound(Now())
MsgBox eoMonth_EarlyBound("4/20/2001")
End Sub
Creating a WorksheetFunction object
If Excel's worksheet functions are to be used lots throughout your code, you could even create a WorksheetFunction object to simplify the calls. For example, this could be a simple way to join multiple strings with TEXTJOIN, or get a response from an API with WEBSERVICE:
Sub Examples()
'requires reference: "Microsoft Excel x.xx Object Library"
Dim xl As Excel.Application, wsf As Excel.WorksheetFunction
Set xl = New Excel.Application
Set wsf = xl.WorksheetFunction
'use EOMONTH to return last date of current month
Debug.Print CDate(wsf.eomonth(Now(), 0))
'use WEBSERVICE return your current IP address from a free JSON API
Debug.Print wsf.WebService("https://api.ipify.org")
'use TEXTJOIN to implode a bunch of values
Debug.Print wsf.TextJoin(" & ", True, "join", "this", , "and", , "that", "too")
'always tidy up your mess when finished playing with objects!
Set wsf = Nothing
Set xl = Nothing
End Sub
Note that these functions may require Excel 2016+ or Excel 365 (aka: Object Library 16.0+.)
Another method I used was:
nMonth = 2
nYear = 2021
lastDayOfMonth = DateSerial(nYear, nMonth + 1, 0)
I have a DateTimePicker named dtpDateSelection. When I select a date I need to break the date down into two variables. I need Quarter to equal the quarter that the date is in. And I need Year to equal the year that the date is in. I thought I knew how to do this but I'm having trouble. Here is the code I've tried:
Dim Year As String = DatePart("yyyy", dtpDateSelection)
Dim Quarter As String = DatePart("q", dtpDateSelection)
And this is the error I get:
Additional information: Argument 'DateValue' cannot be converted to type 'Date'.
A simple solution:
Dim year As Integer = DateTimePicker.Value.Year
Dim quarter As Integer = ((DateTimePicker.Value.Month - 1) \ 3) + 1
So you have the DateTime value from the DateTimePicker.Value property.
Using that you can retrieve the year of the date, like this:
Dim year As Integer = DateTimePicker.Value.Year
For determining the quarter the date is within, try this:
Public Shared Function DetermineQuarter(dateTime As DateTime) As Integer
If dateTime.Month <= 3 Then
Return 1
End If
If dateTime.Month <= 6 Then
Return 2
End If
If dateTime.Month <= 9 Then
Return 3
End If
Return 4
End Function
Now you can get the quarter value, like this:
Dim quarter As Integer = DetermineQuarter(DateTimePicker.Value)
As others pointed out, a DateTime value has a .Month member. For the quarter, I have always used a simple Choose function
Dim quarter As Integer = Choose(DateTimePicker1.Value.Month, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4)
Beyond that, your two lines of code work, but you need to add the .Value to the end of dtpDateSelection. The DatePart function 2nd parameter has an Object type, so it will allow you to pass in a control (which is what you are doing), but the end result will be an error. The .Value changes it to the date selected in the picker.
Dim Year As String = DatePart("yyyy", dtpDateSelection.Value)
Dim Quarter As String = DatePart("q", dtpDateSelection.Value)
I am using the following code in my project. I want to find the number of days by given the last date and now.
Dim BorrowDate As Date
Dim i As Integer
BorrowDate = Date.Parse(txtBorrowDate.Text)
i = DateDiff(DateInterval.Day, BorrowDate, DateTime.Now)
for example, when BorrowDate is "01/Jul/2011" then the result is 7 days which it should be 10 to now. Please help
Since you are using .Net you might try this
Dim BorrowDate As Date = Date.Parse(txtBorrowDate.Text)
Debug.WriteLine(BorrowDate.ToString)
Debug.WriteLine(DateTime.Now.ToString)
Dim ts As TimeSpan = DateTime.Now - BorrowDate
Dim numdays As Integer = CInt(ts.TotalDays)
Debug.WriteLine(numdays.ToString("n0"))
edit: Init the variables and show the dates.