In my datagridview I have 3 columns, lets say Column1, 2, 3.
Column1 is Column2 / Column3.
Problem I have is I'm trying to prevent an error if the user types "0" into Column 2 or 3. I can prevent against it dividing by null or a letter by the following codes:
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i want prevent user order column.i have a datagridview , it has allowuserordercolumns properties and it is set to false. But i didnt see so. i still order column.how can i prevent user ordering column.
View 6 RepliesIf i type this in:
CODE:
I get an error: Error 1 Operator '=' is not defined for types 'System.Drawing.Image' and 'System.Drawing.Bitmap'.
I have also used 'is' instead of '=' but that doesn't work either.
what is code i should use if i want to prevent user not to leave empty word in text box after user click save button. i am using visual studio 2005, database sql 2005.
View 2 RepliesI am trying use barcode for input but prevent user to modify the barcode they scan, user are not allow to input the barcode number by keyboard. i am using vs 2010 vb.net
View 11 RepliesI have an issue with Visual Studio's support for coloring User Types in VB.NET, I'm an C# developer that have been forced to code in Vb.NET by political rules in my organization, and I really misses the support for coloring user types in Vb.NET, I had hoped that this would be solved in Visual Studio 2010 and well in the beta they have added Vb.NET User Type coloring, but the coloring is the same for all user types I cant't have one color for interfaces and one for classes and so on.
View 3 RepliesI'm trying to save what the user types in the vb code Dim user as Inputbox("") for example in a .txt file i can save the textbox and listbox but i cnt figure out how to save the inputbox i really need this to be saved the most.
View 7 RepliesMy question is how best to avoid SQL Injection with the method I am currently using.EDIT (Reasoning): There are many of columns in a number of tables (a number which grows (only) and is maintained elsewhere). I need a method of allowing the user to decide which (predefined) column they want to query (and if necessary apply string functions to). The query itself is far too complex for the user to write themselves, nor do they have access to the db. There are 1000's of users with varying requirements and I need to remain as flexible as possible - I shouldn't have to revisit the code unless the main query needs to change - Also, there is no way of knowing what conditions the user will need to use
View 2 RepliesI'm trying to do something similar to what's described here, but with nullable types.
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int availableUnits = unitsInStock ?? 0;
In VB, it would be this:
Dim availableUnits As Int32 = If(unitsInStock, 0)
However I'm working with db columns, which could be DbNull, and nullable types, which can be Nothing (which is different to DbNull). If a column is DbNull, I want to return Nothing, otherwise return the value. For eg:
Dim availableUnits As Int32? = If(myDataReader("UnitsInStock").Value, Nothing)
The error I'm getting is "Specified cast is not valid" but I'm not sure why. I've tried this as well:
Dim availableUnits As Int32? = If(isDbNull(myDataReader("UnitsInStock").Value), myDataReader("UnitsInStock").Value, Nothing)
Which is messy and just results in the same error. The only thing that works is this:
Dim availableUnits As Int32?
If isDbNull(myDataReader("UnitsInStock").Value) Then
availableUnits = myDataReader("UnitsInStock").Value
Else
availableUnits = Nothing
End If
Which is just silly. Is there a better way of getting nullable db values into nullable variables that I'm not aware of?
I created a windows form which contains a datagridview. I named one of the columns in the grid 'location' which appears to have generated an error. The problem is I cannot load the form to remove the column as an error is generated and when I load the designer code it says do not modify with the code editor but use the windows form designer.
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I am using the following code to insert record into my database but I keep getting the "Error while inserting record on table...Invalid column name 'xxx'." but when I tried to issue the command in SQL server: INSERT Movie_Table VALUES(100, 'Avatar');
Private Sub store_Data()
Dim con As New SqlConnection
Dim cmd As New SqlCommand
Dim iCounter As Integer
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I am having a problem on setting the SQL CE table column a field type. What field type does a column that only accepts only two inputs..
Example: If a table has a column named Gender..it should only accepts two types of input...like Make or Female.
This should be an easy one, looks like I got myself too confused.I get a table from a database, data ranges from varchar to int to Null values. Cheap and dirty way of converting this into a tab-delimited file that I already have is this (shrunken to preserve space, ugliness is kept on par with original):
da.Fill(dt)
' da - DataAdapter '
' dt - DataTable '
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I'm writing a program on CD Collection. My problem is write a code that prevents a user to enter a CD collection name that is already stored in the filename.txt.
The rest of my program is okay, but the only problem is something do with btnAdd control.
Here's my whole program:
Option Explicit On
Option Strict On
Option Infer Off
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i have a form that needs to be maximized in vb.net. i dont want the user to be able to change its size or move it around.
View 5 RepliesI am writing an application that needs to be running all the time and I don't want the user to be able to close it. I don't want to hide the process from Task Manager. All I need is that when the user tries to terminate the process, he has to enter a password.
View 9 RepliesI have the following settings:
ControlBox : False
WindowState: Maximized
Because I want the user to have a full screen application that they cannot close without using my Exit menu. The problem is, they can simply grab the title bar of the form and drag it, exposing the desktop!
I have a Textbox in which the user types in a name for a folder to be created. However, Windows does not allow the followin chars:
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can FileSystemWatcher prevent the user to delete a file ?
View 3 Repliesi have a datagridview with three columns. i set the first column to visible=false, so the user can only see two columns.when the user presses the tab key in the first visible column -- column(1), i want to ignore column(2) so that the user only tabs through the rows in column(1)i can't get it to work. it will always tabs through the rows in column(2) even if i use the column name.
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Well I had a thread going that branched out to this topic, so rather completely veering off the main topic there, I felt creating a new thread was adequate.So as the title says, I'm trying to create a user-defined type. It's not a simple type at that but a user here had showed me a way to fix all my problems. That was to create a type BigDecimal. Which my initial thought was to utilize the BigInteger type. Being that the Integer Part, and Fractional parts would be split off into two variables, both BigIntegers. Which would be combined at the end as a "decimal". However I have many many questions see that this is my first attempt at truly creating a type of my own. So as of right now I'm basically swinging in the dark here.
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In a VB.NET Web Site, the User Types syntax coloring doesn't work. What are potential causes of this? It seems to not understand the difference between a "User Type" and an "Identifier."
Note: C# works as expected.
Is there a way to make a listview select an item based on what a user types? for example, If i have a listview with a column (last name), and the Listview is in focus, I want the user to be able to start typing and have the row select move to the row that has the letters in that column
View 4 RepliesHow can I prevent a single user from logging in to my asp.net website from more than one computer at the same time?I have tried using the application server side state managenment but it is not work properly.
View 1 Replieswhat is code that prevent user to given number less than 8 in the text box. If the user give less then 8 number then message box box will appear which show Minimum Number is 8. Here is my code
Private Sub btnregister_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnregister.Click
If TELEPHONETextBox.Text.Trim.Length = 0 Then
MsgBox("Please Enter Phone Number", MsgBoxStyle.Question)
Me.TELEPHONETextBox.Focus()
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How do I prevent the user from resizing my program during run-time? I know how to disable the max and min buttons at the top, but I can still click the edge and drag it to resize my program. I want to be able to disable this feature so my program stays the same size the whole time.
View 2 RepliesPreferably without turning the "Enabled" property to false, because I still need to output text from it.
I made a custom control in which there is a textbox but I want it used only as an output control, for showing text and stuff. Problem is that as soon as my form opens up the focus is turned to the textbox and I cannot catch my keyboard events on the form anymore(since the other controls are pictureboxes). I need a way to make this box "unclickable" or any way in which it is impossible to attribute the focus.[url]...
I have developed an application in VB.NET. It has 20 forms. All 20 can be opened from a menu strip control. The user should be able to open only one form at a time. How might
View 3 RepliesHow do I prevent users from a inserting a duplicate value using SQL Query
datatype is VarChar(50)
e.g. the name field has already been defined as "Josh", I don't want it to be able to add another "Josh"
Private Sub lv_main_ItemCheck(ByVal sender As Object, ByVal e As System.Windows.Forms.ItemCheckEventArgs) Handles lv_main.ItemCheck
e.NewValue = e.CurrentValue
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