I am taking a business application development class right now and am learning Visual Basic. One of my homework assignments is to calculate the grade needed on the final exam to get an A in the class depending on the midterm score entered by the user. My question is how do I display an error if the value entered is a letter instead of an integer?
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim intMidterm, intFinal As Integer
intMidterm = CInt(TextBox1.Text)
I'm trying to create a linked list of an array of integers. Why is the following implicit conversion required?
When I run the code that contains that conversion, I get the following error.
As a real-time data acquisition user control data (a packet of an array of bytes) arrives every second, is converted into an integer array and inserted into a linked list.
The most recently arrived data is painted as coordinates on a grid at the right of a PictureBox using Graphics.DrawLine (pen,X1,Y1,X2,Y2).
The oldest data (arriving 120 seconds ago) will be drawn at the leftmost portion of the Picturebox.
Why a linked list rather than a list? To display 120 views of time sequence data, the draw routine the most recently inserted node to a node that points to Nothing. How do I limit the length of the linked list to 120 nodes and always ensure that the last node points to Nothing?
Do While Not item Is Nothing item = item.NextItem Loop
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
[Code]...
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 am working on a program where a user either enters "small" or "large" and then the number of toppings. Once the user has done that my program outputs the total cost of a pizza based on user input. If they enter something else besides a number in the txtNumberOfToppings I am trying to show they message box that says "Re-Enter a valid number!" Likewise I am trying to display the error message "Re-enter a number that is 0 or greater!" If they enter a negative number into the textbox. However they do not display when I do enter invalid input.
My Code Author: Adam Fandre Description: User enters the words "SMALL" or "LARGE" and then the number of toppings And program then displays cost based on user input. Comments: Finished Option Explicit On Option Strict On [Code] .....
I am working with a future value application and I am trying to display the calculated future values in a listbox. For instance, I input the monthly investment, the yearly interest rate and the number of years into textboxes and I want the application to list out the future value for each year until the number of years in which I entered is reached. I cannot figure out how to get the code to display the value after each year. I am trying to use the "mod" operator to display the value each time the 12th month comes around.[code]...
I'm just wondering if it's possible to display a string in a integer column in a DataGridView? The reason I'm asking is that I have a column wich displays the place for each runner (it's a sports application). And if the runner is disqualified, it will display "DSQ" instead of the place.
Now, if I want to sort by clicking the column header, there's a problem if there are more than 10 runners. If there are like 12 runners, the sorting will be like this:
Dim asInteger As Integer = 42 Dim aSingle As Single = 39.345677653 Dim Astring As String = "I like Candy" Dim aBoolean As Boolean = True
[code]....
and im getting an error saying anInteger is not declared. Could anyone give me some help to why this is happening and also how it is fixed and give me some information so i can understand why it is not working so i no for future reference. Just reading back over my code i have realized i put
Dim asInteger As Integer = 42 instead of Dim anInteger As Integer = 42
{"Value cannot be null. Parameter name: collection"} Dim Data() As Integer Dim SignalData As New LinkedList(Of Integer())(Data) ' <-- error thrown here
{"Value cannot be null. Parameter name: collection"} Dim Data() As Integer Dim SignalData As New LinkedList(Of Integer())(Data) ' <-- error thrown here
I have a problem, I cannot converted the value of Integer type, which it cannot converted to 'System.Drawing.Point' and 'System.Windows.Forms.Control' .
If I want to populate an ArrayList with values 1 and 2 it works.[code]I found here a link about string to integer conversion in visual basic but I don't know how to deal it to my problem.
I am getting a conversion type error on the red line? Private Function GetGap() As Integer Dim VowelNumG As Integer Dm Vowels as string = "AEIOU" Dim VowelIndexG as integer For VowelIndexG = RandomStr.Length - 1 To 0 Step -1 [Code] .....
I have an unbound datagrid of which I load a csv into it.I then add an additional column and populare it with row numbers:
Private Function AutoNumberedTable(ByVal SourceTable As DataTable) As DataTable Dim ResultTable As New DataTable() Dim AutoNumberColumn As New DataColumn()
Migrated application from vb6 to vb.net. application calling VC++ method. whoes parameter is int/long which is pointer of method
which is passing from vb6 like
VcMethod(addressof vb6Method)
I am getting error ddressOf expression cannot be converted to integer.I know addressof working different in vb6 it givie value in int which is function pointer. Please suggest how can I get value of fuction pointer in vb.net or any other solution in this situation.
Here is my code so far trying to sort the array. The only problem is with Option Strict On, it throws errors on sortedarray(i), and all of the j-1's, j's.Error is dissallows conversions from long to integer
I ran into a strange issue over the weekend while I was working on an asp.net mvc project in vb.net. I created an extension method to convert an integer to the corresponding month it is associated with. I tested the extension method in a console application so I know it is working. In my asp.net mvc project I have a view and want to call the extension method but I get an error that the extension method is not recognized. I imported the namespace it was contained in and still couldn't shake the error. Any idea what's going on? The code is below.
I'm using visual basic to code a program to help with weights and center of balance on aircrafts, as I'm my unit's new air load planner. The math isn't hard to do, it's just that much of it is trial and error, and redoing all the arithmetic over and over again until the aircraft's C/B is in acceptable limits can eat some time up. So, since i'm trying to learn programming I thought this might be a good way to use it for a real-world scenario.
I designed a payroll application and I keep getting the error conversion from string to type Integer is not valid.Also when I enter the name in one of the textboxes it reads form and not my name.[code]
Private Declare Sub Keyboard_Event Lib "user32" (ByVal bVk As Byte, ByVal bScan As Byte, ByVal dwFlags As Long, ByVal dwExtraInfo As Long) [Code] I know the KeyCode when i call this function. Example 13 is the keycode for "Enter". But it says that theres an error on syntax cause KeyCode is an integer not Byte. What kind of variable does it need there? I mean does it need the keycode (which is a number) or a character e.g. "a"? [Code]
this code below it gives me this error "error: Incorrect integer value: '' for column 'MPotProspect' at row 1"
[code]...
this give me another error "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 1/" another way i tried when i highlight the myDatarow.Item(8).tostring and see what is inside there no data found.. but the other from mydatarow 7 to 1 there is data.. but in the database all of the fields including mydatarow(8) has data inside... why in mydatarow(8) when the program run it turn to null... may be the will cause the error...
I used error provider tool to display the error when the textbox is empty. when the error message is displayed immediately it is inserting the record into the database.I want to clear the error and then insert. how to take the control to textbox?
I used error provider tool to display the error when the textbox is empty. when the error message is displayed immediately it is inserting the record into the database.I want to clear the error and then insert. how to take the control to textbox?..Imports System.Data.OleDb
Public Class Form1 Dim myConnection As OleDbConnection Dim myCommand As OleDbCommand
trying to get my hands wet on vs 2010 and i downloaded samples from ms site but when i tried to run some of the DB samples i received this sql error: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) any ideas how to get around on this?
I know it's possible in asp.net to create a custom error page in a web app, by putting the following line in the web.config: <customErrors mode="RemoteOnly" defaultRedirect="frmErrorPage.aspx" />
I have had to do this for my web app, since it is clearly much tidier than letting the program bomb out with it's ugly default error page. My custom error page just has the customer's logo and a brief message saying "Error has occurred. Please return to homepage"The trouble now is that I have no way of knowing what caused the error, when a customer reports it.
Is there a way to make the actual error message appear on this custom error page too?
I'm populating a checkedlistbox with this loop. Dim week As Integer For week = 1 To 51 Step 2 CheckedListBox1.Items.Add(week) Next And get this result 1 3 5 7 9 11 13 etc. This is how I want it 01 03 05 07 09 11 13 etc.
