How To Handle Db Nulls
Oct 11, 2010I am retrieving a database object and trying to set the values of the object's fields to various textboxes in my vb.net page
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Allow Nulls When I Programmatically Bind A Textbox?
Jul 28, 2011I was thinking I should just change the value to "" when a null value has been read from the datasoure. But then I thought maybe there is a property that allows this. is there?
txtComments.DataBindings.Add("Text", rowEquipItem, "Comment")
Inserting Datetimepicker Value Into Database, 'does Not Allow Nulls'
Apr 24, 2007Here's a bit of code
Private Sub QhBindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles QhBindingNavigatorSaveItem.Click
Me.Validate()
[Code]......
Search A String Buffer With Nulls (chr(0))?
Sep 25, 2009I need to search a buffer for a string of characters.The buffer is essentially a binary file (it's an image) and contains lots of chr(0) characters.The string I need to locate also contains chr(0) characters. In fact it is the following string:
chr(100) & chr(0) & chr(0) & chr(163)
This is a marker in the image file for items I need to process.So I though I would do the following:
Dim sFileBuffer as String = system.io.file.readalltext("myimagefile")
Dim sLookFor as String = chr(100) & chr(0) & chr(0) & chr(163)
Dim iLocation as Integer = sFileBuffer.IndexOf(sLookFor)
The problem is that, although the characters in sLookFor definitely exist inside of sFileBuffer - IndexOf will always return -1 (not found).I tried the following:
Dim Marker() as Byte = {100, 0, 0 , 163}
Dim sLookFor as String = System.Text.Encoding.UTF8.GetString(Marker)
Dim sFileBuffer as String = system.io.file.readalltext("myimagefile", Encoding.UTF8)
Dim iLocation as Integer = sFileBuffer.IndexOf(sLookFor)
But this appears to only find occurrences of Chr(100) & Chr(0) - not the full 4 character sequence I desire. It appears to see the second Chr(0) as a termination of the search string.I think the sticking point here is the null. Yes - I can string.replace(chr(0), Chr(255)) in both the sLookFor and the sFileBuffer and adjust my search accordingly - but that seems like a mess to me.Is there not a way to search a buffer of binary data? I've tried working with byte arrays - but there appears to be no way to easily search for a sequence of byte values - just individual elements in the array.
Log4net Saving Errors To Db, Getting Nulls In Parameters?
Dec 14, 2011I am getting null values in Environment, ApplicationName, ApplicationPath, ExceptionData when inserting rows in a SQL Server 2005 DB. My log4net configuration is as follows :
<log4net>
<appender name="ADONetAppender_SqlServer" type="log4net.Appender.AdoNetAppender">
<bufferSize value="1" />
[code].....
MySQL Parameters / AddWithValue - How To Avoid To Check For Nulls
Sep 15, 2010Let's say I have a MySql stored procedure that inserts a record with some nullable CHAR fields. In VB.NET if I don't check for Nothing (or Null in other languages), I get an exception from the db driver, so I write:
command.CommandType = CommandType.StoredProcedure;
command.Parameters.AddWithValue("_name", if(name Is Nothing, "", name)).Direction = ParameterDirection.Input;
And this is the first thing I don't like; I'd like to pass Nothing and the driver knows it has to put NULL in the Db. But then, in the stored procedure, I have to check back the field if it is empty:
INSERT INTO mytable
(name, -- other 200 char fields)
VALUES
(NULLIF(_name, ''),
-- other 200 char fields
)
I have to check for nothingness/emptiness twice. Is there a better, more direct, way? Even worse, for non reference types (i.e: Integers) the check for nothingness makes no sense, since a primitive type can't be nothing (yes, I could set an Integer to a non meaningful value, say -1 for a positive id, but...).
Simplifying ElseIf Statement Nulls And Strings Involved?
Feb 1, 2010Is there an easier way to do this?
The .ColorReportedDate, .ColorTypeKey, .IsColorKeyNull, etc are from my strongly typed dataset row.
If .IsColorKeyNull Then
.ColorReportedDate = Now()
ElseIf cboColorType.SelectedValue <> .ColorTypeKey Then
.ColorReportedDate = Now()
End If
Joystick Handle - Use Only The Handle Of The Component?
Mar 23, 2009I wrote an application to handle a joystick with directinput. It works fine if it uses the handle of the main window but it doesnt happen the same if the handle is the one of the component that contains the joystick's operation.
I mean:
main form handle: 15
component handle (which is inside the window and the joystick needs the focus of this component to work): 25
It always work if the handle i initilizate the device is the main form (15).How can i use only the handle of the component?
DataGridView - Convert Nulls To Empty Strings And Display It In The Grid As Empty Strings
May 14, 2009I 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]...
Asp.net - Getting .NET To Handle CSS Files?
Jul 25, 2011Possible Duplicate: Can .NET intercept and change css files?
I have configured IIS6 to get .NET to handle css files.I did the following steps
Launch IIS Manager Right-click on Default Web Site Click on the Home Directory tab Under Application Settings click on Configuration.Add a new association for .css and map it to .NET executable:
C:WINDOWSMicrosoft.NETFrameworkv2.0.50727aspnet_isapi.dll
How can I check if this is working, i.e. I want to change the default style of a page depending on the url, i.e. if the referer url is http://intranet, it should continue to use the old existing style style1.css, if the referer url is http://intranetv2, it should use the new style style2.css.
Can't Get A Handle On The Syntax?
Aug 6, 2009I can't get a handle on the syntax. Can anyone give me a simple demo?
View 3 RepliesGet A Handle On The Correct Way?
Jul 2, 2009I am trying to get a handle on the correct way and easiest way to do things. By easiest I am not talking about being lazy just accessing and modifying later on. I have started using my own classes and such but I have a few questions. Sometimes I want to create a control on the fly through code instead of using the designer. Should I create this control in the main form file or in a separate class? If I make it in another class it seems harder to access later on. Then again if I dont know that the control is going to be created(user clicks a button to add a control) how can I access it? Also it seems alot harder to access certain things when it is in another class. For example if I create a new window in a class and then want to check if it is there or not it is alot harder to do.
View 5 RepliesGet Handle Of A Combobox By API?
Feb 13, 2012Are there anyone know how to get the handle of a standard Combobox using API?
View 3 RepliesGet Handle Of NotifyIcon?
Dec 13, 2011How do i get the handle of a NotifyIcon?
View 4 RepliesGet The Handle From A Control?
May 8, 2009I need the intPtr for a form. Control.FromHandle(control) gives me the control from a handle, but I need the opposite--get the handle from a control. How do I do this?
View 2 RepliesGet The Handle Of A Control?
Apr 27, 2009I need to get the handle of a control as an IntPtr to pass to a screen capture class in vb.Net 3.0. Tried this but get an invalid handle exception.
Dim hwnd As IntPtr = Runtime.InteropServices.GCHandle.Alloc(CanvasMap)
Getting Handle Using Win32 Api?
Jan 24, 2012I am trying to create a small utility that tracks desktop usage in detail, to the level of individual text boxes etc.... in other applications. However, it is proving quite tricky. I thought I had it nailed using the Windows api. The below code is just a snipet of the code but essentially it provides me the handle of the control that the mouse is over. I thought from here, it would be easy to to the same thing but to provide the handle of the control that the cursor was actually clicked on, for example, if someone is filling in a text box in an application, they would not necessarily move the mouse to get to the text box, they may tab to it. Does anyone know if there is a way to get the handle of the control that is in use?
Private Sub Timer1_Tick(sender As Object, e As System.EventArgs) Handles Timer1.Tick
Dim ptx As Integer = Cursor.Position.X
Dim pty As Integer = Cursor.Position.Y
[code]....
Getting The Handle Of Another Application?
Apr 12, 2011I need to get the handle of a window with a specific name from my vb.net application. The form isn't actually from my application.
View 1 RepliesGetting The ProcessID From Handle?
Jun 23, 2009I am going mad about getting the process id for one existing handle on VB2008.I tried both GetWindowThreadProcessId(hwnd, pid) and GetProcessId(hwnd), while PID always returns 0, I tried the same things in VBA of Excel, it works perfect, so this is somewhat weird,
View 8 RepliesHandle A Event From DLL ?
Jun 22, 2010I have referred DLL in my project. I have to handle the event from DLL in VB.net code. I guess we can do using WithEvents. Can you give me complete picture?
View 2 RepliesHandle Results Of More Than 1 Row
May 6, 2009I am having a SP run in my VB application every 10 seconds to check for any new rows that have been inserted to the database since the last check. What is the best way to do this? Most likely it will be 0 or 1 rows, but I am afraid at random times it maybe more than 1 and so I thought I would fill it in a DataSet, but I came in here to see if there are any other better ways. If dataset is the best way, how do I do a For Each Row in the dataset to process some VB code for each row?
View 20 RepliesHandle SQL Null In .NET?
Jan 19, 2009I read stuff from a SQL DB (database) using a data set. Some of the columns in the DB may contain NULL. I want to go through the table in the dataset and print, or use in some other way, the data. But when I try to use a certain data that corresponds to a NULL in the DB my program crashes.How can I detect - in the dataset - that it has no value and that I shouldn't try to use it?
Private Sub Get�rendenLista(ByVal e As System.EventArgs)
'----------------------------------------------------------------------
' This function fetches a list of �rende from the table �rende
'----------------------------------------------------------------------
Dim cno As New SqlConnection
[code]....
How Does One Handle Handles
Sep 12, 2009The short program below runs just fine when it is the only item on a form. However, when I put it into the ItemInsertTemplate of a ListView control, I get the following message:
Handles clause requires a WithEvents variable defined in the containing type or one of its base types
Line 30: Protected Sub btnDate_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnDate.Click
The error message identifies Line 30 as the problem.I get the same message for Sub clnEvent_SelectionChanged How do I correct this?
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="clnControl.aspx.vb" Inherits="clnControl" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
[code].....
How To Get A Handle To A Printer
Nov 22, 2009Does anybody know if there is an API function that would let me cancel a print job.I already know how to get a handle to a printer and how to enumerate the print jobs using the printer handle.
View 1 RepliesHow To Handle Associated Files
Feb 25, 2009how to make VB handle my associated files.I made a program that opens fine when from the EXE file. But however, when I try to open it from the associated file, it behaves the same way as if opened from the EXE.So, where (in what method?) do I tell VB how to handle those files?
View 8 RepliesHow To Handle Database Changes
Jan 27, 2010I have several installations of my Linq-to-Sql app running in the field. Now I've created a new version, which adds a new column to a certain table. I've added this column in the dbml file. But when updating the installation, I want to preserve the existing database. How to handle this? Linq-to-SQL doesn't seem to like this inconsistency.Is there an easy way to update the existing database using my new dbml file?
View 1 RepliesHow To Handle Eject Key
Jul 27, 2010my computer model has an eject key on top of it (touch sensitive), this handles the CD ejecting. But Windows doesn't native support this button, and I have to use Dell QuickSet to use this button (otherwise it does nothing). I need to hook onto this key and eject the CD Drive when it is pressed (I already have the ejecting and the hooking done). But I have no idea how to detect this key? There is no key in the key list for VB.NET, and I don't know what the eject button sends (Numerical wise) so I can't handle it that way. Does anybody know how to handle the eject key?
View 2 RepliesHow To Handle Errors
Mar 10, 2010I am making a vb.net program that calls several other subprograms. None of them effect the other.If there is an error in 1 of them, how do you record the error but continue on to the next subprogram with out stopping everything ?
View 1 RepliesHow To Handle Inner Exception
Jun 22, 2010I was working on a project in my VB.NET Express and suddenly my code that was working fine and starting up as normal gave me this error:
{An error occurred creating the form. See Exception.InnerException for details. The error is: Corrupt .resources file. Got an unexpected EndOfStreamException while trying to read the ResourceReader header.}
When I'm trying to run my application, it doesn't open my main form.
How To Handle Input
Nov 23, 2009Ok, I'm not sure how to explain this, but I'll give it my best shot.I want my console application to be able to do one function I have when you click one option on the windows context menu, and another function when you click another option.
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