Im exporting a datagridview to excel but i want to check if this datagridview has any data before i allow the user to export.Heres some code,
data=datagridview, con.ejecutasql=oledb returns datatable.dt = con.ejecutaSql("SELECT * FROM sistema")data.DataSource = dtPrivate Sub print_excel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[code].....
[code]... Check Datagrid Is Empty?
View 1 RepliesIm using this code to populate a datagridview:
Private Sub PopGrid(ByVal Filename As String)
Dim ConnectionString As String = "Driver={Microsoft Excel Driver (*.xls)};READONLY=FALSE;DriverId=790;Dbq=" & Filename & ";"
Dim Con As New OdbcConnection(ConnectionString)
[code]....
But when i look at the grid, there is alot of empty cells that is NOT empty in the excelsheet.
I'm extracting data form a mysql using a huge query made up of three unions to searc on different tables for a telephone number. e.g. contacts, leads, etc.Iy workd perfectly in a sql tool and is well tested.When I run the query in visual studio, I get a result, two columns contaon the same image you get when a webpage image link is boken. These columns should contain a mobile phone number and an ID.Both are stored on mysql as varchars.No data is presented for these columns even though it exists with gaps
View 3 Repliesmy program crashes when my datagrid view is empty.
It crashes at this
M = Allow_grid.SelectedCells(1).Value
I know its because the grid is empty. when the grid is empty it has a "-1" as the selected value index right?
Is ther a way to test if the index is "-1".
if grid_selected index <> "-1" then
M = Allow_grid.SelectedCells(1).Value
else
[Code]....
I think we can just draw an image that resemble the grid using this article : drawing in a datagridview Currently creating a way to make the image drawn in tile mode. Each time I develop a datacentric application using VB.NET regardless of how much the data displayed in the datagrid, I always want the grid to display full row of empty data, not just blank panel. Can we achieve this using VB.NET design time property? And also, we must not trigger the display of vertical scrollbar this way..
View 1 RepliesI get an empty string when calling the .Text property. Refer below for snippet:[code]The internet search advises to use Items(col).Cells(2).FindControl(..), the problem with that is FindControl finds the control by ID, BoundColumn doesn't allow you to insert an ID for it.
View 1 RepliesI am wondering if data grid automatically shows a first column (empty) before the others, if that can be edited out.
View 14 RepliesThe problem is that if you never enter anything into a cell for a new row then that cell is never validated. This is a problem because I have columns that should not be null. I am doing the check in the row level validation and storing the information about which cells are empty that should not be empty. The row level validation works fine and the row level validation error indicator goes on,(red exclamation mark at the beginning of the row) but I also need a visual indicator on the individual cells that are in error.
I am thinking that setting the HasError property for the cells that are in error should cause them to display n error style (the default red border). Is there a way to this this either from XAML (perferably) or from code?Alternatively I could cause those cells to re-validate when the row editing is finished. Does anyone know how to do this?
I have a datagrid that will be accepting data from an external measuring device via the serial port. The grid is also open to editing records as well. Part of the process of making this grid user friendly is to intercept the "enter" key and move to the next cell until there is a value in the cell. This is only for some cells, other cells can be blank. I have worked out how to intercept the "enter" key from another post on this forum. Here is the code:
[Code]...
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]...
I've created a little procedure that I use to verify if a value does actually exist. I'm currently using this all throughout my application for things such as verifying if a control's EditValue actually has a value. I was wondering if I have missed any scenarios where a value would not be available, missing, non-existent, blank, etc., and how would I incorporate in my procedure.
Public Function ValueExist(ByRef CheckValue As Object) As Boolean
Try
ValueExist = True
If IsDBNull(CheckValue) Then
ValueExist = False
[Code] .....
I am working on an app and cannot remember how to verify that the first three characters in a zip code are a specific number.
View 1 RepliesThis 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 not been able to successfully verify a user with LDAP for an ASP.NET web application. I have done so on our own network against Active Directory, but this is against a server outside of our network that is OID (Oracle Internet Directory).Usually, I use the following code with no problem.
Dim myDirectoryEntry As New System.DirectoryServices.DirectoryEntry("LDAP://1.2.3.4:999/OU=SomeOU,DC=Something,DC=com")
myDirectoryEntry.AuthenticationType = System.DirectoryServices.AuthenticationTypes.Sealing
myDirectoryEntry.AuthenticationType = System.DirectoryServices.AuthenticationTypes.Secure
Try
[Code]...
After that, I haven't been able to find a method to verify a user's log in information with their password and then pull back some information.
I know this is a stretch, but I am looking for some .NET help with checking Joomla passwords.For those not familiar with Joomla password scheme, it looks like this: {MD5Hash}:{SALT}HEre is the code I am using:Joomla password:
9322a02004887255b76a6a8e8971aea7:5JTTaPQjA88247nCKkTILtv8TXFtZCED
User submitted password: 123456
Dim m5t() As String = dr("password").split(":") // splict Joomla password
[code].....
What is the easiest way to verify if a number is odd or even?I'm setting up a program, and it is checking if a user input number is even or odd, if its odd, it runs this, if even, it runs this.Its a simple if/then, else statement.
View 2 RepliesHow would you verify if an IP address resolves to a computer name correctly from a textbox?
View 6 RepliesI have a dll installed on my machine and want to find a way to verify this programatically with VB.Net. I have been trying to use LoadLibrary but it always returns a zero. Can someone provide a code snippet of how I might do this?
Also, if there is another way to verify that a dll is installed, without having to supply a full path, please let me know.
I have bulk email id in database. I need to verify whether email id is existing or not before sending a mail in asp.net.
View 1 RepliesThere is a situation that I couldnt handle, I have 4 TextBox's and I am assigning the text to variable after loosing focus for 4 TextBox's as below;
(Variables assigned under class Form1)
Private Sub TextBox1_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.LostFocus
[code]....
what I have to do is a magicbox, i need to put 9 numbers in 9 text boxes, and verify that they r not the same, im doing it trough the TextChanged event. i do have some code, but is incomplete... and doesn't really work
Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
TextBox1.TextChanged,
TextBox2.TextChanged,
TextBox2.TextChanged,
[code]...
[code] this code need to verify the level of login, i mean if the user is admin then proceed to the next form with privileges but if is a visitor then proceed to the next form but without privileges.
View 1 RepliesI've got records that I am adding to the database but I wanted to know how I can verify if the record has been inserted into the database. Below is the code that I am using
Imports Microsoft.Office.Interop.Access.Dao
Public DatabasePath As String = "C:WB2020WB2020WB2020inDebugWBS3000A.ACCDB"
Dim AccessEngine As New DBEngine[code]......
I am trying to verify that a string contains nothing but known values. In this case, I need to make sure it contains only "Shift", "Control", or "Alt", but not necessarily all of those. For example, these should be true: "Shift + P", "Shift + Control + H", "Alt + U; but these should not: "Other + P", "Shift + Fake + Y", "Unknown + Shift + E" etc.This is the code I tried to use:
If Not shortcut.Contains("Shift") Or Not shortcut.Contains("Control") Or Not shortcut.Contains("Alt") Then
MessageBox.Show("Invalid")
End If
I'm having difficulty wrapping my head around the needed logic to do this. I'm assuming there's a logic operator that can do this?
I am attempting to compare a bitwise clone object to its parent to check for changes using:
If Not objCP.Equals(objCPClone) Then
'do something
End If
and it always compares as not equal even immediately after creating the clone. How should they be compared to check for changes?
I am writing an Excel addin to read/insert/update/delete SQL data. I am looking for tips or code samples to check if the user running the addin has select/insert/update/delete permissions. this would work on SQL 2000, 2005 and 2008. I have found the following which works for SQL 2005 (and likely 2008, though I have not tested).
Use AdventureWorks
Go
SELECT * FROM fn_my_permissions('Sales.vIndividualCustomer', 'OBJECT');
Go
[code]....
I need to create a function that will verify a password.The function will be named IsValid.
View 1 RepliesPrivate Sub frmRegistration_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
cn.Open()
cmd.Connection = cn
cmd.CommandText = "Select * from Registration"
[Code] .....
How can I decrypt a file encrypted in vb.net? Is there a possibility here?
View 2 Replies