If I delete the top row of my datagrid, or load a page without any data in the datagrid, I get a NullRefrenceException error. "Object reference not set to an instance of an object."suggest a way for it to only run the default values needed sub if a row exists in my datagrid, else ignore it?
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I have a d.g.v. with two columns. One is set as date and the other is set as decimal. If there is a row and a number is typed in the decimal column, you can delete it and leave the cell empty. However, the program will not let me delete the contents of a date cell and leave it empty. It just gives me the default error dialog saying that I need to put the contents in proper date form and it doesn't let me leave it blank.
How can I make it so that it allows me to leave the cell blank?
I am still trying to accomplish a tiny flatfile based database. So far everything works fine except for the fact that 'data records' are not sorted alphabetically. My 'data records' are saved in files and their filenames are used as ID. Now all the data are stored iin the files, so, my application reads out the values and adds them to the 'database'. Unfortunately, I couldn't find any way to sort this added data alphabetically by name - everything else works perfectly and I am almost finished, except for the sorting.
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By default, the DataGridView padding (.ColumnHeadersDefaultCellStyle.Padding and .DefaultCellStyle.Padding) is set to 0 (zero). However, when you run the application and look at what's in the DataGridView control, there is default padding of 3 pixels (Left) in the data cells and a default padding of 7 pixels (also Left) in the header cells. I don't seem to have any control over these 3 and 7 pixel offsets. For Top, Bottom, and Right, there are similar or greater pixel offsets that I also don't seem to have access to. I want to be able to specify exactly the pixel offset I want, assuming a default pixel offset of 0 (not 3 and 7).
View 2 RepliesObviously error handling is a major factor in making a good application. If a error happens letting a user know what has gone wrong.But some times error handling may(i think) not be needed. Example.
Private Sub RemoveCheckedl()
Try
For Each Item As ListViewItem In lst.CheckedItems[code]....
also when error handling it's could to think about what type of errors could be made.
Catch ex As Exception
MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
even though this catches the error and displays a msg, it may not be a great message for the user so he/she can understand.
In a new program I'm including a button so the user can send en email with feedback.
The problem: On Windows Vista & Windows 7, an error pops up with the following message:
[Code].....
I am receiving the same error. However, on Windows XP, both of these codes are working fine. Email client used (as default) is Outlook 2007.
I want to get the value of the selected item for example I want to get the first cell which is the quantity and store it in a textbox which I will select in the datagrid. How can I do that I am new with datagrid.
View 19 RepliesOn my emailer program ive created a messagebox to appear if any of the textboxes are empty when i clcik send, its works fine (first time) but if i leave a textbox empty for the second time and click send i get an error.[code]
View 20 RepliesI'm looking at a project that will use the speech recognition stuff provided with .NET, but need a tutorial or two to introduce me to it.
View 2 RepliesI have a combobox which contains a sample of names selected from a table.Currently the default name displayed in the box is the 1st name found in the table. What I would like to do is display the name of the person who is doing the selection as the default. The name is stored in a public variable 'PubName' and I do not want the user to be able to type into the combobox themselves.Is this possible?
View 2 RepliesI am creating a program in VS 2010 which obviously uses Framework 4.1 However now that I am trying to test the program I am realizing usually only developers like us have this version.. Is there any way to downgrade the needed version of the framework for my program Currently I run it on my test computer and it asks me to download 4.1 version.
View 4 Repliesi'm coding a small app.i need to use regular expressions.I've got a huge string. and i need to find some substrings and put them into variables.for instance:<span class="(some constant class)">sb's Name</span> I need to cut "sb's Name" and put it into variable.how to do this using regular expressions?I know, that I can use webbrowser and whole DOM structure connected with it. But I can't, so I must use RegExp.
View 1 RepliesHow can I tell what the size of my program is and how much disk space is needed to install. When I publish the program and install it on another machine it will show up in the control panel but does not show what size the program is?Also when I publish updates with it says something like installing 10mb. Is this an additional 10 mb everytime, I guess not, but can someone explain what it all means?
View 10 RepliesI'm using visual basic 2010 and i am able to import the raw data from excel and into my datagirdview but i am unable to get the code to add the values of raw data in column 2 and 3 and show the answer in column 5. Do i need to loop it?
The entire project is in the attachment take a look at it.
This is the entire code i have now:
Imports System.Data.SqlClient
Imports System.IO
Imports System
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I'm trying to fill a ComboBox with values from a column in a database...I'm trying to use code I found in jmcilhinney's CodeBank post at url. credits to him since it's basically 100% his code in my image below.I've tried 4 methods before this, and I've been receiving the same error, so it must be my fault... the image below shows the code and the problem.
View 1 RepliesI am unable to load the dat into the data Grid. Here is where I keep getting stuck.
dgvOleDb1 = table.Select
dgvOleDb1.DataSource = DataGridViewEditMode.EditProgrammatically
dgvOleDb1.DataSource = ds.Tables(0)
I am confused; I am using VB2010, IBM.iSeries.DB2 on an as400 V5R4. I am trying to establish an OLEDB connection, and return the values from the selected table to a DataGridView. I had one of the admin's make me file named GARBAGE, in the Rprtaccess catalog. In the past, I have been able to connect via access and an ODBC connection. My project is too big for access, and the SQL middleware we have is clunky and not user friendly. This is a program that will generate the SQL statements, specifically the WHERE: clause and populate the datagrid with the selected criteria. In essence I am making a user friendly striped down program, that has variables that are manipulated by the end user, and the rest, referenced tables and libraries are coded.
Imports System.Data.OleDb
Imports System.Exception
Public Class Form11
[code]....
i have this code i want to populate datatable with datagrid. . . .but this is error in column name i dont know why. . . .
Dim dt As New DataTable
Dim rptdoc As ReportDocument
With dt
[code]....
I am populating my datagridview as such: Private Sub LoadDatagridview()
Dim lf As New IO_LogFile
If Not lf.DataFileExists Then
WriteLogInfo("Utilities.DisplayUserlog.LoadDatagridview", "Log files does not exist for " & combobox_CompanyId.Text & ". Please select another company.", True, MsgBoxStyle.Critical)
Exit Sub
End If
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My data displays without using everything in the 'with datagridview_Userfile' but I need to format the screen. I used this code in another program and it's identical and has no problems so I am bewildered.
i would like to know whether is there any ways of setting a masked value of "0.00" to a textbox? So when user input a value, let's say "200". The textbox will interpret it as "2.00". Similarly, if user enters "1000" it will display as "10.00".
View 4 Repliesi am developing vb.net windows application. i have a combobox. In that i added items in its properties as follows
<- - - select- - - >
school
hospital
office
others
when i run my application i need to display the selected item as "<- - - select- - - >" but it display empty.....
I've been getting "Connection forcibly closed" errors and in researching a resolution, I have seen suggestions to money with the following web.config options, which currently are not set in my web app. Before I change them, I'd like to know what they are currently set to. Can someone tell me how to read these values from .NET code, preferably VB.NET, though C# is fine.
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A Windows service written in VB.NET is using the My.Settings namespace for simplicity. There are only three settings to read, and these are read within the constructor of the ServiceLauncher.
I am attempting to install the service as such:
installutil GID.ServiceLauncher.exe
And this is successful, however the config settings it is using are not the ones within the GID.ServiceLauncher.exe.config file, instead it is using the ones baked into the app as Default Settings within Settings.Designer.vb (marked with DefaultSettingValueAttribute). [The questionable wisdom of Microsoft not allowing a developer to ignore default settings is another question entirely].
How can I further diagnose this issue, and maybe force a reload of settings? I tried calling My.Settings.Default.Reload, however this did nothing. All settings are application settings, and only differ by "value" from those in the auto generated file.
I have successfully attached the debugger using System.Diagnostics.Debugger.Launch() and true enough, the settings are still the default settings.
In anticipation of the question, the background: The reason for requiring configuration settings is because this is a very straightforward service that simply executes an exe; and this exe is in configurable location. There are other reasons also, such as I wish to have the service name configurable without recompiling.
What is the difference between these two methods for defining property value defaults? [code] Is there a reason to use one method over the other for defining the default property values in a class?
View 24 RepliesI have a bounded datagridview and have some code in row validating event. When i add a new line by writing something in one of the cells of the new row, and if in the middle of the process i wish to cancel this new row, if i use the escape key i get an exception, something like, Index (number of the removed row) does not have a value. After the exception the exception the row it's removed...
How can i make the row validating to work correctly?I have this code in the start of rowValidating
vb.net If MyDataGridView.Rows(e.RowIndex) IsNot Nothing AndAlso Not MyDataGridView.Rows(e.RowIndex).IsNewRow Then
End If
I create a class "Planet" that can be inherited. One of the purposes of inheriting is to create a template with different default property values. Eg:
Public Sub New
MyBase.New
MyBase.ForeColor = Red
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Now, to stop the defaults serializing in the InitializeComponent method, there are 2 ways:If I've implemented the properties using the 'DefaultValue' attribute, and made them overridable, the attribute can be overriden with the new value.The problem with this is, there's no way to just make just the attributes overridable, as opposed to the whole property.I could implement every property with protected Reset'PropertyName' and ShouldSerialize'PropertyName' methods. However, this is a bit of a pain in the arse.Is it, generally, an important consideration to ensure that someone who overrides your base class has the ability to change the default values of a property?
I currently receive spreadsheets from clients which include several date fields. Since these are coming from many different sources, the date formats can vary widely (although they will all be US format). It could be "April 19, 2010", "4/19/2010", "2010-04-19", etc. I would very much like to use the DateTime.Parse function rather than having to write my own parsing function--I don't want to have to write out every possible combination of date strings.
The problem is, the DateTime.Parse function includes default values if all values are not supplied. So if the field comes in as "03/2009", since no day was specified, the function will return a datetime equivalent to "3/19/2009" (today's day along with the values given). I cannot use this. If a client provides a date that is incomplete, my program must produce an error, not fill in default values for them. Is there a way to tell DateTime.Parse not to use default values? Or perhaps there's another function that can parse multiple string formats into DateTime type without using defaults?
How do you read the default values from the appName.exe.config file? My application only reads these values on first installation. Subsequently, it reads the updated values sitting in the user.config file.
View 2 RepliesI need some help with coding that is attached to a reset button. I need it to reset the form's controls (textbox,combobox,etc.. to it's default values, but I can find what to use. I've found information on clearing the values which I don't want to do. I just want to reset them as if the form just loaded.
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I have in my database a table for Products with one field as Price. For each invoice i want to be able to change this default price, so in my table for Invoice Details I have made another field called Price1. When I am entering invoice details and i enter a product number i want my program to select the relevent default 'Price' and insert it into 'Price1' so that it will be editable and so it can be saved to my database.
View 2 RepliesLooking at the new VB 2010 features, I stumbled upon support for Auto-Implemented Properties.Since I'm working with C#, this seemed quite familiar, but I noticed that VB did add a feature I would love to have in C#: setting a arbitrary default value for the auto-implemented property:I really like the clean usage of auto-properties in C#. This would save us the effort of introducing a backing field and hooking it up to the property everytime we simply need a default value, thereby cluttering up the code unnecessarily.I was wondering why this wasn't introduced in C# as well? What could be the rationale for not doing this? Is a syntax discussion going on, or are there technical limitations to implementing this?
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