I am getting an unexpected result parsing a string into a date string. Here is the code snippet I'm using to test: Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
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Quick question: I'm trying to parse dates in the following format to their equivalent DateTime data type, but for some reason it's failing. The string format is: 28/May/2009:17:43:04 +0000Or: dd/MMM/yyyy:hh:mm:ss zz00Here's the code I'm using:Dim provider As New CultureInfo("en-US")Dim d As DateTime = DateTime.ParseExact(value, "dd/MMM/yyyy:hh:mm:ss zz00", provider)
View 2 RepliesI get unexpected results when I use DateTime.ParseExact.
Here's my test code:
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It looks like it's because the day is systematically added by ParseExact even though I only specify the time in the format. My question is: How can I read just the time with DateTime.ParseExact?
I have a text string like this which I will need to parse: FriMar1200:00:00EST2010 And I used the following Date.ParseExact("FriMar1200:00:00EST2010", "dddMMMddHH:mm:sszzzyyyy", Nothing) And it is giving me a A first chance exception of type 'System.FormatException' occurred in mscorlib.dll error.
View 2 RepliesI'm trying to add the date and time of Today into a Sql-database-field that has the datetype datetime.
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the msgbox gives me the following result: 29/01/2011 18:49:21 my sqlException gives me the following error: 102 - Incorrect syntax near '18'. Is it better that i set the datatype to char in my sql database? It's maybe a bit easier? When I do that, can I calculate with these date?
For a project I need to convert a date field in my SQL Server 2008 Database into a VB.net ListOf. Most of the records in StartDate field are NULL. VB.net doesn't recognize null values for DateTime.I need the NULL values to be dismissed, as they will be returned in a ListOf for a web service that I'm creating.
Here is my syntax and a sample of the current returned values in the XML message of the ListOf:
Class Property StartDate() As System.Nullable(Of DateTime) = Nothing
asmx.vb myUserRoleAppInfo.StartDate = myPermissionUser.StartDate
XML Message (Listof)
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I am using the WebBrowser control with VB.Net (2010 Express) to get exchange rates from ft.com. (Note: I realise that there are simpler ways of getting exchange rates, but it is a learning exercise as much as anything else). I am navigating to a webpage, setting the values of a textbox and two listboxes, and then trying to get the resulting exchange rate which will be displayed as text. Trouble is, the result is not being displayed. I probably need to trigger an event to force the page to update, but I have tried this and it hasn't worked. [code] The 'onchange' event is intended to trigger an update, but it doesn't. I have tried a few variations without success (including "invokeMember"). So at the moment the amount and the to/from currencies are correctly set on the page, but the resulting rate is not shown.
View 2 RepliesI am currently having a headache on how to solve this problem that i am facing. here is the situation: I have a combobox and a list box on the main form. The combobox will get the data from the ms access database. In the database, i have the details of a person's IC, Name and DOB say for eg on one entry I have D215311523C,SHAWN,13/04/1987 So now, my combobox on form load will show the list of dates in the database to allow the user to search base on the date itself by clicking on the selected date. So when the user clicks on the particular date say 13/04/1987, people in the database whose birthday is 13/04/1987 will be shown on the listbox.Meaning to say if i have 3 entries whose dates are the same 13/04/1987, 3 entries will appear. If there is only two entry, then two results will be shown. But now, when i do a single click on the date, one result will be shown. That is correct. But the problem is when i click on the same date again, three of the same results will be shown on the list box. that is it will display : 13/04/1987 13/04/1987 13/04/1987 which is not the case. Then it will show more duplicates of the same results if i click more times on the same date which should not be the case.
Dim n As Integer
Dim numbers() As Integer
Dim StartFrom As Integer
Dim EndAt As Integer
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I am using a datagrid in my where i am having four columns. In first column the parameter values are entered and in the second column measured value is entered and in third column the nominal value is entered.Inthe fourth column the result is displayed by subtracting the measured value and nominal values. I am doing this calculation in Datagrid cell validated event. What i want is,there will be many rows in the grid,when typing the value in the third column the corresponding result will be displayedin the rowof theresult column,save button will be displayed while the form loads,when the calculate part is completed that is there should not any cell of the resut column empty then i should enable the save butto.
View 2 RepliesI am encountering the following issue So i have a device that sends stuff at the serial port, i then parse it and put it into an array of bytes like that:
Dim HCI_Command_Rcvd_Byte() As Byte All good till here What i wanna do is make an array and put this result every time the serial port gives me a new result, for example:
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Basically what i wanna do is let the port parse the messages, fill in the array with the result at an empty spot in this array and then i will have a separate thread that will look in into this array in each non empty space and after it looks into the non empty space it will use or discard the info and also mark this space as empty (after it checked)
I'm trying to load a datable into a datagridview, but column1 ("date") should be converted to a datetime, so I can sort it when I click on the datagridview header. I tried this, but it gives me that there is no column 0 or one. I have 2 columns: "ID" and "DateStart"
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I've got a datatable with a DateTime field that I want to sort using a DataView. I only need the Time part of the column though, and not the date. I can't get it to show just the time and not the date as long as its a DateTime column. I know I could convert it to a string to get the time, but then it wont sort correctly.
View 1 RepliesI am having a major issue understanding why this code runs fine once and then when run a second time causes the "String was not recognized as a valid DateTime." exception. This program loops through folders and subdirectorys and retrieves the file dates from the last modified date of the file , Its only when i click New Report to reset all the values in the settings which clears all object lists and resets all the other values that this issue occurs.
This is the value being passed to this function:
#6/14/2011 4:46:51 PM# (The file inside the subdirectory,s last modified date.)
The function is
Public Sub setFileDate(ByVal fileDate As DateTime)
'Format the datetime from the filedate to a UK culture.
Dim myDateTime As DateTime = DateTime.Parse(fileDate, ukCulture.DateTimeFormat)
'Set the current files date.
dFileDate = myDateTime.Date
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I am working on a program. I've got the following
Private Sub frmTabel_Activated(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Activated
Dim strHoofding As String
strHoofding = "Geleend bedrag : " & _
strRechtsUitgelijnd(Format(glngBedrag, "‚¬ #,##.00"), 15) & vbCrLf & _
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What it should do is placing the four formats but I am only getting result from glngBedrag'
Like this: [URL]
I have the following code which returns a single row and column of an MS Access database. My goal is to put it into the Text property of a textbox. Can please someone explain me how to do it?
Dim cmd1 As New OleDbCommand("SELECT NOME From FORN_NIB Where NUMERO = ?", cn)
Dim P2 As New OleDbParameter
cmd1.Parameters.AddWithValue("P2", ComboBox1.Text)
Dim Reader1 As OleDbDataReader = cmd1.ExecuteReader()
Dim dt1 As New DataTable
dt1.Load(Reader1)
i've been working on a project that works with a MySQL DB, and every time the SQL executes and adds the listbox items it wont show the first result i have no idea what i am doing wrong here.
vb.net
Dim NwConn As MySqlConnection NwConn = New MySqlConnection NwConn.ConnectionString = "server=XX.XXX.XX.XX; user id=XXXXX; password=******; database=*****;" Try NwConn.Open()
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hope someone can give me a solution or if someone can tell me what i have been doing wrong.
I'm just converting a date to a string but I'm getting this error. It's not listed as one of the normal exceptions to the datetime.tostring method. Googling around, it looks like it's an actual bug where it thinks StartDate is an int--but that's no help to me, as I just need to convert the date.
dim StartDate as nullable(of date)
dim Date1 as string
if not StartDate is nothing then
Date1 = StartDate.tostring("yyyy-mm-dd")
end if
how to convert string to datetime and calculate date
View 3 RepliesI'm trying to match a certain DateTime value with the current system DateTime. I have a timer and a label on a form. Timer interval is set to 1000. When the form loads, the timer starts ticking. As soon as the current DateTime matches the value of the variable, it shows a message in the label. When I'm writing the following code, the values don't match even if the current system DateTime is equal to the variable. Label1 isn't showing 'Times Matched':[code]The default format of 'Now' is the same as I have stored in dtmVar variable. So there's no question of format mismatch. Does that mean 'Now' is not actually a DateTime property? Provided, my O.S. is Windows Vista Ultimate and all date/time settings are set to default.
View 1 RepliesI'm trying to match a certain DateTime value with the current system DateTime. I have a timer and a label on a form. Timer interval is set to 1000. When the form loads, the timer starts ticking. As soon as the current DateTime matches the value of the variable, it shows a message in the label.
When I'm writing the following code, the values don't match even if the current system DateTime is equal to the variable. Label1 isn't showing 'Times Matched':
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
Dim dtmNow As DateTime
[Code]....
Why is it so? The default format of 'Now' is the same as I have stored in dtmVar variable. So there's no question of format mismatch. Does that mean 'Now' is not actually a DateTime property? Provided, my O.S. is Windows Vista Ultimate and all date/time settings are set to default.
datetime1 and datetime2now two fields are have data ( date )in table recordi want to update only datetime2 is an emptyi am using visual basic 2010 ( visual studio 2010
View 1 RepliesI am using an Access database to store (filepaths to) pictures as well as comments people can leave on them. One picture can have multiple comments, so the tables look like this:
_____________ _____________
|Photos | |Comments |
|------------| |-------------|
|Id (PK) | |Id (PK) |
|PhotoPath | |PhotoId (FK) |
|Description | |Comment |
|____________| |_____________|
What I need to do now is retrieve a list of all Photos along with their Comments. So I have a class Photo with a collection of Comments:
vb.net
Public Class Photo
Public Property Id As Integer
Public Property PhotoPath As String
Public Property Description As String
Public Property Comments As List(Of Comment) End Class Public Class Comment
Public Property Id As Integer
Public Property PhotoId As Integer
Public Property Comment As String
End Class
I can retrieve the records using an INNER JOIN query (right?), as such;
SELECT Photos.*, Comments.*
FROM (Photos INNER JOIN Comments ON Photos.Id = Comments.PhotoId)
From the result of that, for each row in the result I can create a new Photo instance, set its properties and put it in a List(Of Photo) for further processing (displaying). However, how do I handle the Comments? With this query I would get a lot of duplicate Photos. I'd get a row for each comment, but most of these rows will represent the same photos... How do I handle this the best way? I have used inner join queries before, but only for a one-to-one relationship so I never had this problem before. Now when I finally need a one-to-many relationship I realize I've no idea how to handle this appropriately...
There must be some standard way of handling this? When I previously handled cases like this I didn't use an inner join, I just retrieved all Photos first, then iterate through them and run another query to retrieve the Comments that belong to that Photo (SELECT * FROM Comments WHERE PhotoId = ?). That works fine, but when the tables are getting larger it is getting noticeably slower. So I want to do it in a single query, I definitely want to avoid running hundreds of queries if I can.
Currently I'm doing a resistance calculator. If i got 3 combo boxes which let user to choose the color code of a resistor, how to make the resistance of the resistor(resistance after count according to the color code choose by the user) go into a listbox after click "Enter" button? And also initialise the color code choose by user just now and the resistance after count.
View 2 RepliesI have a DataTable with two DateTime columns: "start_time" and "end_time".Now, I want to add a third column that calculates the difference between the two DateTimes. But I can't seem to figure out how. I've tried to set the .Expression-value to "start_time - end_time", but it says that "-"-operator is not allowed on DateTime.
View 4 RepliesI am extracting datas from the table to display in datagridview1 as shown in image1.
Now I want to search the datagridview1 and display the result in datagridview2 as shown in image2.
Please do refer the attached images.I am using Visual basic 2010 for this.
I am extracting datas from the table to display in datagridview1 as shown in image1. Now I want to search the datagridview1 and display the result in datagridview2 as shown in image2.
I am using Visual basic 2010 for this.
I want to create a LINQ to entities query getting data(join) out of two tables and bind the result as datasource to a datagridview.
Unfortunately I seem to stumble upon a syntax issue.
Table 1 : dcpricing.tblpricing
Table 2 : dcpropertydetail.tblpropertydetail
Grid: grdpricing
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I just read about DataSet in VB.NET, it uses disconnected concept. My question is: if my apps has "List All" button that query data from 1 table in the database, and that table has "very very very" many rows, so my DataSet will be filled with those data and eat up memory. Can I limit the data that being put to the DataSet from that query? But I want to be able to retrieve the next data from the same query if the user want to see it?
For example:
I have 1000 rows in my database, and i query all of them. But I just want 200 rows being inserted to my DataSet, but if the user want to see rows number 201 and so on, I want to be able to retrieve the next 200 rows, and so on. So it just like cutting those data into a group of 200 rows. Can I do this with the concept of "disconnected" of the DataSet?
I have set up text boxes for user to pick a number 1-20 and to enter a word as well. Then, press submit button. What's supposed to display in result textbox is the word that many number of times. For example if the number is 5 and the word is hello, then "hellohellohellohellohello" should appear. I don't know how to complete my For...Next function to append the word to the result.
Public Class Ch6ex1
Private Sub btnsubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnsubmit.Click
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I try to compare Datetime.Now with a Datetime variable I set, using the Datetime.CompareTo() method. I use a timer to compare these every second and display the result, but as the current time approaches the time I set, the result changes from 1 to -1, but never 0, which means these two are never equal. I'm suspecting the Datetime structure contains milliseconds?
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