I want fill my combobox with time values like (08:00, 08:10, 08:20 until 09:50) step=10 minutes but the result is like (8:00, 8:10, 8:20, 8:30, 9:-20,9:-10, 9:00, 9:10, 9:20).
My code doesn't show the value like 8:40, 8:50 and he also show negative value like 9:-20, 9:-10).
So please how can I resolve this problem?
Heure_rdv.Items.Clear()
Dim nbr_minute2 As String
For i = 480 To 590 Step 10
Dim nbr_heure As Integer = cint(i / 60)
Dim nbr_minute As Integer = (i - (nbr_heure * 60))
nbr_minute2 = CStr(nbr_minute) + "0"
If ((i - (nbr_heure * 60)) = 0) Then
Heure_rdv.Items.Add(CStr(nbr_heure) + ":" + nbr_minute2)
Else
Heure_rdv.Items.Add(CStr(nbr_heure) + ":" + CStr(nbr_minute))
End If
Next
This is how I should do try it in VBA.
Should be similar in VB.NET
DIM i As Integer 'Counter 1
Dim ii As Integer 'Counter 2
' make 1st loop for hours
for i = 8 To 9
' mkae 2nd loop for minutes
for ii = 0 To 50 Step 10
'
Heure_rdv.Items.Add(i & ":" & ii)
next
next
This could be done with fewer lines of code using linq
Dim steps = Enumerable.Range(0,6)
Dim items as List(Of String) = new List(Of String)()
items.AddRange(steps.Select(Function(x) "08:" & (x * 10).ToString("D2")))
items.AddRange(steps.Select(Function(x) "09:" & (x * 10).ToString("D2")))
Heure_rdv.DataSource = items
First we create a list of integers from 0 to 5 (6 elements), then using these elements we create the strings required multiplying each element of the integer list by ten and converting the result to a two digit string. We do this one time for the 8 hour and one time for the 9. Finally we could set the combo datasource to the resulting list of strings.
Related
The following is an exercise I am having trouble with.
The button’s Click event procedure should display the number of integers from 14 to 23 in one of the labels and the sum of those integers in the other label. Code the procedure using the For…Next statement. Save the solution and then start and test the application. (The procedure should display the numbers 10 and 185.)
I'm able to display the sum 185 but not understanding how to display the amount of numbers (10) between 14 to 23. Any help is appreciated.
Public Class frmMain
Private Sub btnShow_Click(sender As Object, e As EventArgs) Handles btnShow.Click
Dim intSum As Integer
For intNum As Integer = 14 To 23
lblShow.Text = lblShow.Text & intNum.ToString & " "
intSum += intNum
lblSum.Text = intSum.ToString
Next
End Sub
End Class
Just declare sum and count local variables and increment them appropriately in the For. You need only update the Label.Text once after the calculations have been done
Dim intSum As Integer
Dim intCount As Integer
For intNum As Integer = 14 To 23
intSum += intNum
intCount += 1
Next
lblSum.Text = intSum.ToString()
lblShow.Text = intCount.ToString()
I understand your homework has the For requirement, but .NET has some functionality built in which can produce a list of numbers, sum them, and count them.
Dim start = 14
Dim finish = 23
Dim numbers = Enumerable.Range(start, finish - start + 1)
lblSum.Text = numbers.Sum().ToString()
lblShow.Text = numbers.Count().ToString()
Both methods produce your required output
display the number of integers from 14 to 23
This can be interpreted in a couple of ways:
Display the count of integers between the two numbers (e.g. 23 - 14)
Display each individual integer between the two numbers (e.g. 14, 15, 16, etc.)
If it is the former, then simply subtract the larger number from the smaller number and display that value in a label:
LabelIntegerCount.Text = (23 - 147).ToString()
If it is the latter, then inside of your For/Next loop append the currently iterated counter to the label:
For intNum As Integer = 14 To 23
LabelIntegerCount.Text &= intNum.ToString() & Environment.NewLine
' ...
Next
I want to do the following thing: if I have a Textbox1.Lines:
2
5
15
21
45
and I want to for example get the number left 15 and get the number right 15.
Output: Textbox2.Lines 15 21
5 15
How should I do this? example for the number 2 want substring 2 5
Module Module1
Public Function FirstWords(input As String,
count As Integer) As String
Dim words = count
For i As Integer = 0 To input.Length - 1
' Decrement word count when we reach a space.
If input(i) = " " Then
words -= 1
End If
' When no words remaining, return a substring to this point.
If words = 0 Then
Return input.Substring(0, i)
End If
Next
Return ""
End Function
how should i do this to work?
You can separate them into an array of strings with the Split function, like in this example:
Dim input as String = "2 5 15 21 45"
Dim numbers as String() = input.Split(" ")
For Each s as String In numbers
Console.WriteLine(s)
Next
You just have to figure out how to extract the numbers you want from the lot. Have fun!
I am developing an application using Visual Basic 2010 for hydraulic calculations of a pipe network.
This application uses a lot of iterations and loops, depending on the user input and size of network. Most of the results have to be saved temporarily to be used for the next step of calculations.
Firstly, I used a DataGridView to save the results but as the number of iterations increased, the application became very slow.
Now I am trying to create a DataTable, then populate it with some initial results (this part was successful). The obtained DataTable has some columns that are not populated like so:
22 24 10
3 16 22 9 15
16 12 24 13
14 21 10 23 12 1
24 18 23 2 1
Other calculations are performed and a certain value (X) is obtained.
Now I am trying to loop through the columns of a specific row to check if the calculated value (X) equals to one of the values in those columns.
My question is: How can I loop through only the columns that have values (avoiding the columns containing NULL values) for a specific row?
I am a beginner in VB.net. I hope my question is clear as I didn't provide any code.
Thanks in advance for you help.
This is the initial code I used:
Results.DGVInitial.Rows.Clear()
Results.DGVFinal.Rows.Clear()
For m As Integer = 0 To NetworkLayout.DGVNetworkLayout.Rows.Count - 1
Results.DGVInitial.Rows.Add()
Next
Dim I As Integer = NetworkLayout.DGVNetworkLayout.Rows.Count - 1
Dim Sec(I), Ini(I) As Integer
Dim Hyd(I), Dia(I), Len(I) As Single
Dim Qsec(I), Qini(I), Vsec(I) As Single
Dim U(I), Y(I) As Single
Do
I = I - 1
Sec(I) = NetworkLayout.DGVNetworkLayout.Rows(I).Cells(0).Value
Ini(I) = NetworkLayout.DGVNetworkLayout.Rows(I).Cells(1).Value
Hyd(I) = NetworkLayout.DGVNetworkLayout.Rows(I).Cells(6).Value
Dia(I) = NetworkLayout.DGVNetworkLayout.Rows(I).Cells(4).Value
Len(I) = NetworkLayout.DGVNetworkLayout.Rows(I).Cells(3).Value
Dim V As Integer
V = Results.DGVRandomGen.Rows(TotalNum_Runs - 1).Cells(I).Value
Qsec(I) = 0
Dim q As Single = 0
For n As Integer = 0 To Results.DGVInitial.Rows.Count - 1
If Results.DGVInitial.Rows(n).Cells(1).Value = Sec(I) Then
q = Results.DGVInitial.Rows(n).Cells(0).Value
Qsec(I) = Qsec(I) + q
Else
Qsec(I) = Qsec(I)
End If
Next
If V = 1 Then ' if the hydrant is open
Qini(I) = Hyd(I) + Qsec(I)
Else ' if the hydrant is close
Qini(I) = Qsec(I)
End If
Results.DGVInitial.Rows(I).Cells(0).Value = Qini(I)
Results.DGVInitial.Rows(I).Cells(1).Value = Ini(I)
Results.DGVSectionDischarges.Rows(TotalNum_Runs - 1).Cells(I).Value = ini(I).ToString("F2")
Now instead of using
V = Results.DGVRandomGen.Rows(TotalNum_Runs - 1).Cells(I).Value
I would like to replace the "DGVRandomGen" with a DataTable called "DT_Random"
Like I said I am a beginner so I am not sure how to code it but it will be something like this:
For DT_Random.Rows (TotalNum_Runs - 1)
For Each col As DataColumn In DT_Random.Columns
If DT_Random.Rows(TotalNum_Runs - 1).Item(col) = I Then
Qini(I) = Hyd(I) + Qsec(I)
Else
Qini(I) = Qsec(I)
End If
Next
But I want to avoid Null values as not all columns are populated
Thanks
Maybe this will help you:
Dim myXvalue = 24
Dim myDataTable As New DataTable
myDataTable.Columns.Add("Col1")
myDataTable.Columns.Add("Col2")
myDataTable.Columns.Add("Col3")
myDataTable.Columns.Add("Col4")
myDataTable.Rows.Add(22, 24, 10, DBNull.Value)
myDataTable.Rows.Add(3, 16, 22, DBNull.Value)
myDataTable.Rows.Add(24, 18, DBNull.Value, 24)
For Each column As DataColumn In myDataTable.Columns
If IsDBNull(myDataTable.Rows(0).Item(column)) Then
MsgBox("DB Null Found At: " & column.ColumnName)
Continue For
End If
If myDataTable.Rows(0).Item(column) = myXvalue Then
MsgBox("Match: " & myDataTable.Rows(0).Item(column) & " found at " & column.ColumnName)
End If
Next column
Just a quick example, you may need to restructure it a bit, but at least it shows you how to access the values in your datatable by columns. I would do a function that passes a row index as a parameter and returns a boolean. Create two booleans inside the sub, one for dbnull existing in the row, and one for finding a matching value. If dbnull bool is false, and match value is true, then return true. Just make sure you loop all the columns and dont exit early.
If you need me to elaborate let me know.
With reference to this question,
Changing Row Colour according to condition
I got familiar with Conditional formatting. However I still face this problem.
I am using this code to convert time into Time in Minutes.
Dim TestString As String
TestString = Me.Duration
Dim TestArray() As String
TestArray = Split(TestString, ":")
Dim Hours As String
Dim Minutes As String
Dim Seconds As String
Dim HoursMinutes As Integer
Dim MinutesMinutes As Integer
Dim SecondsMinutes As Integer
Hours = TestArray(0)
Minutes = TestArray(1)
Seconds = TestArray(2)
HoursMinutes = CInt(TestArray(0)) * 60
MinutesMinutes = CInt(TestArray(1))
SecondsMinutes = CInt(TestArray(2)) / 60
Dim TimeInMinutes As Integer
TimeInMinutes = HoursMinutes + MinutesMinutes + SecondsMinutes
Me.Duration = TimeInMinutes
However, for some reason this is not working.
Have you any ideas how can I do this for seperate rows?
Thanks in advance
ADD:
I tried creating a field for Minutes, the problem is that they will get all the same number.
the below code has a String variable called dateTime which stores the current date and time in this format: 27/08/2013 10:55:52
The dateTime String is getting split into a Variant arr array
Split(dateTime, Chr(32))(1) returns the time 10:55:52 part of the dateTime variable
then Split(Split(dateTime, Chr(32))(1), ":") splits the time into 3 numbers using : (colon) as delimiter
So you end up with with arr holding # of hrs, # of minutes, # of seconds.
The CLng((arr(0) * 60) + arr(1) + (arr(2) / 60)) returns an Integer/Long representation of the calculated time value
Stick the below sub in a fresh module and run it
Sub Convert()
Dim dateTime As String
dateTime = now
Dim arr
arr = Split(Split(dateTime, Chr(32))(1), ":")
MsgBox "The time " & Split(dateTime, Chr(32))(1) & vbCrLf & _
" as Integer is equal to " & CLng((arr(0) * 60) + arr(1) + (arr(2) / 60))
End Sub
I'm trying to randomize an array from numbers 0 to 51 using loops but I just cannot seem to pull it off. My idea was that
Generate a Random Number
Check if this random number has been used by storing the previous in an array
If this random number has been used, generate new random number until it is not a duplicate
If it's not a duplicate, store it
My attempt:
Dim list(51) As Integer
Dim templist(51) As Integer
For i As Integer = 0 To 51 Step 1
list(i) = i
Next i
Do While counter <= 51
p = rand.Next(0, 52)
templist(counter) = p
For n As Integer = 0 To 51 Step 1
p = rand.Next(0, 52)
If templist(n) = p Then
Do While templist(n) = p
p = rand.Next(0, 52)
Loop
templist(n) = p
Else
templist(n) = p
End If
Next
counter += 1
Loop
For n As Integer = 0 To 51 Step 1
ListBox1.Items.Add(templist(n))
Next
It will be a lot easier if you just have a list of all of the possible numbers (0 to 51 in your case), then remove the number from the list so it can't be picked again. Try something like this:
Dim allNumbers As New List (Of Integer)
Dim randomNumbers As New List (Of Integer)
Dim rand as New Random
' Fill the list of all numbers
For i As Integer = 0 To 51 Step 1
allNumbers.Add(i)
Next i
' Grab a random entry from the list of all numbers
For i As Integer = 0 To 51 Step 1
Dim selectedIndex as Integer = rand.Next(0, (allNumbers.Count - 1) )
Dim selectedNumber as Integer = allNumbers(selectedIndex)
randomNumbers.Add(selectedNumber)
allNumbers.Remove(selectedNumber)
' Might as well just add the number to ListBox1 here, too
ListBox1.Items.Add(selectedNumber)
Next i
If your goal is to get the numbers into ListBox1, then you don't even need the "randomNumbers" list.
EDIT:
If you must have an array, try something like this:
Function RandomArray(min As Integer, max As Integer) As Integer()
If min >= max Then
Throw New Exception("Min. must be less than Max.)")
End If
Dim count As Integer = (max - min)
Dim randomNumbers(count) As Integer
Dim rand As New Random()
' Since an array of integers sets every number to zero, and zero is possibly within our min/max range (0-51 here),
' we have to initialize every number in the array to something that is outside our min/max range.
If min <= 0 AndAlso max >= 0 Then
For i As Integer = 0 To count
randomNumbers(i) = (min - 1) ' Could also be max + 1
Next i
End If
Dim counter As Integer = 0
' Loop until the array has count # of elements (so counter will be equal to count + 1, since it is incremented AFTER we place a number in the array)
Do Until counter = count + 1
Dim someNumber As Integer = rand.Next(min, max + 1)
' Only add the number if it is not already in the array
If Not randomNumbers.Contains(someNumber) Then
randomNumbers(counter) = someNumber
counter += 1
End If
Loop
Return randomNumbers
End Function
This is good enough for your assignment, but the computer scientist in my hates this algorithm.
Here's why this algorithm is much less desirable. If zero is in your range of numbers, you will have to loop through the array at least 2N times (so 104+ times if you are going from 0 to 51). This is a best case scenario; the time complexity of this algorithm actually gets worse as the range of numbers scales higher. If you try running it from 0 to 100,000 for example, it will fill the first few thousand numbers very quickly, but as it goes on, it will take longer and longer to find a number that isn't already in the list. By the time you get to the last few numbers, you could potentially have randomly generated a few trillion different numbers before you find those last few numbers. If you assume an average complexity of 100000! (100,000 factorial), then the loop is going to execute almost ten to the half-a-millionth power times.
An array is more difficult to "shuffle" because it is a fixed size, so you can't really add and remove items like you can with a list or collection. What you CAN do, though, is fill the array with your numbers in order, then go through a random number of iterations where you randomly swap the positions of two numbers.
Do While counter <= 51
p = rand.Next(0, 52)
While Array.IndexOf(list, p) = -1
p = rand.Next(0, 52)
End While
counter += 1
Loop
Haven't written VB in about 5 years, but try this out:
Function GetRandomUniqueNumbersList(ByVal fromNumber As Integer, ByVal toNumber As Integer) As List(Of Integer)
If (toNumber <= fromNumber) Then
Throw New ArgumentException("toNumber must be greater than fromNumber", toNumber)
End If
Dim random As New Random
Dim randomNumbers As New HashSet(Of Integer)()
Do
randomNumbers.Add(random.Next(fromNumber, toNumber))
Loop While (randomNumbers.Count < toNumber - fromNumber)
Return randomNumbers.ToList()
End Function
Ok, that was painful. Please someone correct it if I made any mistakes. Should be very quick because it's using a HashSet.
First response to forum on stackoverflow - be gentle.
I was looking for a way to do this but couldn't find a suitable example online.
I've had a go myself and eventually got this to work:
Sub addUnique(ByRef tempList, ByVal n, ByRef s)
Dim rand = CInt(Rnd() * 15) + 1
For j = 0 To n
If tempList(j) = rand Then
s = True
End If
Next
If s = False Then
tempList(n) = rand
Else
s = False
addUnique(tempList, n, s)
End If
End Sub
Then call the sub using:
Dim values(15) As Byte
Dim valueSeen As Boolean = False
For i = 0 To 15
addUnique(values, i, valueSeen)
Next
This will randomly add the numbers 1 to 16 into an array. Each time a value is added, the previous values in the array are checked and if any of them are the same as the randomly generated value, s is set to true. If a value is not found (s=false), then the randomly generated value is added. The sub is recursively called again if s is still true at the end of the 'For' loop. Probably need 'Randomize()' in there somewhere.
Apologies if layout is a bit wobbly.