I am trying to perform a SQL Select query based on the user input from a Checked List Box. I was able to find some code, but the solution doesn't seem to be working. On the debug, it keeps crapping out on line 3 and I have no idea why.
Any help would be grateful.
Dim DistrictString As StringBuilder = New StringBuilder()
For h = 0 To Me.District.CheckedItems.Count - 1
If Me.District.CheckedItems(h).Selected Then
DistrictString.Append(Me.District.CheckedItems(h).Value & ",")
End If
Next
With some of the advice, here is the newly edited version of the code, it is now crashing on the Append line.
The new error is 'Public member 'Value' on type 'String' not found'
Dim DistrictW As String
Dim DistrictX As String
Dim DistrictString As StringBuilder = New StringBuilder
For h = 0 To Me.District.CheckedItems.Count - 1
DistrictString.Append(Me.District.CheckedItems(h).Value & ",")
Next
DistrictW = DistrictString.ToString
DistrictX = DistrictW.Substring(0, DistrictString.Length - 1)
If Me.District.CheckedItems.Items(h).Selected Then
DistrictString.Append(Me.District.CheckedItems.Items(h).Value & ",")
End If
Use CheckboxList.Items
Thank you to everyone who helped, this is the solution that I implemented
Learned a lot from this little exercise.
Dim DistrictW As String
Dim DistrictX As String
Dim DistrictString As StringBuilder = New StringBuilder
For h = 0 To Me.District.CheckedItems.Count - 1
DistrictString.Append(Me.District.CheckedItems(h).ToString & ",")
Next
DistrictW = DistrictString.ToString
DistrictX = DistrictW.Substring(0, DistrictString.Length - 1)
Since it appears you are creating a expression like ...xyz in ('a', 'b', 'c', 'd')... the following code might be more appropriate:
For h = 0 To Me.District.CheckedItems.Count - 1
DistrictString += "'" & Me.District.CheckedItems(h).Value & "',"
Next
DistrictString = DistrictString.Substring(0, DistrictString.Length - 1)
There is no point in messing with the .SELECTED property at all. Everything that's checked is 'selected' for your purposes.
Related
I have this skill checkboxlist which contains skills that can be selected by the user. If the user select two skills,two records will be inserted to the table.
I tried this one:
Dim varSkillID As Integer()
varSkillID = split(skills, ",")
If varSkillID(0).value > 0 Then
Dim sql As String = Nothing
For I = 0 To varSkillID()
sql = "INSERT INTO tblConstituentSkills (skillID) VALUES ( " & varSkillID.Value & ")"
Next I
end if
but its not working. Thanks!
I also tried this code.
Dim varSkillID() As String = Split(skillID, ",")
For i As Integer = 0 To varSkillID.Length - 1
If varSkillID(i) <> "" Then
Using sql As New SqlProcedure("spInsertSkill")
sql.AddParameter("#ConstituentIdNo", constituentIdNo)
sql.AddParameter("#skillID", varSkillID(i))
sql.ExecuteNonQuery()
End Using
End If
Next i
It works when I only select single skill. But if I select two or more skills this error appears "Nullable object must have a value."
please use the editor help to design your request. It is very hard to read.
What does the errormessage say?
There is an End If missing
Where does constituentIdNo.Value is coming from?
To call the Sub:
Call r101("123456", "1,2,3,4")
the Sub:
Public Sub r101(ByVal constituentIdNo As String, ByVal skills As String)
Dim varSkillID() As String = Split(skills, ",")
Dim sql As String = Nothing
For i As Integer = 0 To varSkillID.Length - 1
If varSkillID(i) <> "" Then sql = "INSERT INTO tblConstituentSkills (ConstituentIdNo, skillID) VALUES (" & constituentIdNo & ", " & varSkillID(i) & ")"
Next i
End Sub
This is not the cleanest code, but the best I could create from your given feedback.
I don't see why to convert skills to integer.
I just read this and saved me.separate comma separated values and store in table in sql server
Thanks stackoverflow!you're a savior!
I'm learning for loop and I cannot get this problem fixed.
The problems are in the following codes.
dim rt as integer = 2
dim i As Integer = 0
dim currentpg as string = "http://homepg.com/"
For i = 0 To rt
currentpg = currentpg & "?pg=" & i
messagebox.show(currentpg)
next
'I hoped to get the following results
http://homepg.com/?pg=0
http://homepg.com/?pg=1
http://homepg.com/?pg=2
'but instead I'm getting this
http://homepg.com/?pg=0
http://homepg.com/?pg=0?pg=0
http://homepg.com/?pg=0?pg=0?pg=0
Please help me
Thank you.
You probably need something like this:
Dim basepg as string = "http://homepg.com/"
For i = 0 To rt
Dim currentpg As String = basepg & "?pg=" & i
messagebox.show(currentpg)
Next
Although a proper approach would be to accumulate results into a List(Of String), and then display in a messagebox once (or a textbox/file, if too many results). You don't want to bug user for every URL (what if there are 100 of them?). They would get tired of clicking OK.
First of all, you went wrong while copying the output of the buggy code. Here is the real one.
http://homepg.com/?pg=0
http://homepg.com/?pg=0?pg=1
http://homepg.com/?pg=0?pg=1?pg=2
It does not work because currentpg should be a constant but it is changed on each iteration.
Do not set, just get.
MessageBox.Show(currentpg & "?pg=" & i)
Or you can use another variable to make it more readable.
Dim newpg As String = currentpg & "?pg=" & i
MessageBox.Show(newpg)
Also, your code is inefficient. I suggest you to change it like this.
Dim iterations As Integer = 2
Dim prefix As String = "http://homepg.com/?pg="
For index As Integer = 0 To iterations
MessageBox.Show(prefix & index)
Next
i'm having problems on how to display continuously with for loop statement, what i want it to display with be data1, data2, data3, data4 and so on with a comma and single space on each value. here's what i do :
Dim str
For i = 0 To FuelPrice.Items.Count - 1
str = FuelPrice.Items(i).SubItems(0).Text
MsgBox(str & ", ")
Next
but i did not get what i expect..lol sorry for the noob question though for i am just totally a noob..lol thanks in advance
Use a StringBuilder to accumulate your text in a single buffer and then display it outside the loop
Dim str as StringBuilder = new StringBuilder()
For i = 0 To FuelPrice.Items.Count - 1
str.Append(FuelPrice.Items(i).SubItems(0).Text & ", ")
Next
' To remove the comma added at the end
if str.Length > 0 then
str.Length -= 1
End If
MsgBox(str.ToString())
You can also use a generic list (or an array if you prefer), then concatenate the result together. I think this code is cleaner.
Imports System.Collections.Generic ' If not already referenced
Dim str As New List(Of String)
For i = 0 To FuelPrice.Items.Count - 1
str.Add(FuelPrice.Items(i).SubItems(0).Text)
Next
MsgBox(String.Join(", ", str))
I am trying to make a program that changes letters in a string and i keep running into the obvious issue of if it changes a value, say it changes A to M, when it gets to M it will then change that M to something else, so when i run the code to change it all back it converts it as if the letter was originally an M not an A.
Any ideas how to make it so the code doesnt change letters its already changed?
as for code ive just got about 40 lines of this (im sure theres a cleaner way to do it but im new to vba and when i tried select case it would only change one letter and not go through all of them)
Text1.value = Replace(Text1.value, "M", "E")
Try this:
Dim strToChange As String
strToChange = "This is my string that will be changed"
Dim arrReplacements As Variant
arrReplacements = Array(Array("a", "m"), _
Array("m", "z"), _
Array("s", "r"), _
Array("r", "q"), _
Array("t", "a"))
Dim strOutput As String
strOutput = ""
Dim i As Integer
Dim strCurrentLetter As String
For i = 1 To Len(strToChange)
strCurrentLetter = Mid(strToChange, i, 1)
Dim arrReplacement As Variant
For Each arrReplacement In arrReplacements
If (strCurrentLetter = arrReplacement(0)) Then
strCurrentLetter = Replace(strCurrentLetter, arrReplacement(0), arrReplacement(1))
Exit For
End If
Next
strOutput = strOutput & strCurrentLetter
Next
Here is the output:
Thir ir zy raqing ahma will be chmnged
Loop through it using the MID function. Something like:
MyVal = text1.value
For X = 1 to Len(MyVal)
MyVal = Replace(Mid(MyVal, X, 1), "M", "E")
X = X + 1
Next X
EDIT: OK upon further light, I'm gonna make one change. Store the pairs in a table. Then you can use DLookup to do the translation, using the same concept:
MyVal = text1.value
For X = 1 to Len(MyVal)
NewVal = DLookup("tblConvert", "fldNewVal", "fldOldVal = '" & Mid(MyVal, X, 1) & "")
MyVal = Replace(Mid(MyVal, X, 1), Mid(MyVal, X, 1), NewVal)
X = X + 1
Next X
Here's another way that uses less loops
Public Function Obfuscate(sInput As String) As String
Dim vaBefore As Variant
Dim vaAfter As Variant
Dim i As Long
Dim sReturn As String
sReturn = sInput
vaBefore = Split("a,m,s,r,t", ",")
vaAfter = Split("m,z,r,q,a", ",")
For i = LBound(vaBefore) To UBound(vaBefore)
sReturn = Replace$(sReturn, vaBefore(i), "&" & Asc(vaAfter(i)))
Next i
For i = LBound(vaAfter) To UBound(vaAfter)
sReturn = Replace$(sReturn, "&" & Asc(vaAfter(i)), vaAfter(i))
Next i
Obfuscate = sReturn
End Function
It turns every letter into an ampersand + the replacement letters ascii code. Then it turns every ascii code in the replacement letter.
It took about 5 milliseconds vs 20 milliseconds for the nested loops.
I'm trying to make a calendar in vb.net and I have come across this problem. I want to append some text into an existing datatable row. When I watch my debugger it says:"In order to evaluate an indexed property, the property must be qualified and the arguments must be explicitly supplied by the user.".
Dim aantalRijen As Integer = 1
For x = 0 To 6
Dim dttopdrachten As New DataTable
dttopdrachten = opdrachtendao.getOpdrachtenByDate(Today.AddDays(x))
If dttopdrachten.Rows.Count > aantalRijen Then
aantalRijen = dttopdrachten.Rows.Count
End If
Next
For z = 0 To aantalRijen - 1
Dim r As DataRow
r = dttAgenda.NewRow()
dttAgenda.Rows.InsertAt(r, z)
Next
For i = 0 To 6
Dim aantalItems As Integer = 0
Dim dttopdrachten As New DataTable
dttopdrachten = opdrachtendao.getOpdrachtenByDate(Today.AddDays(i))
aantalItems = dttopdrachten.Rows.Count
For j = 0 To aantalItems - 1
Dim info As String = dttopdrachten.Rows(j).Item(0).ToString & vbCrLf & dttopdrachten.Rows(j).Item(2).ToString & vbCrLf & dttopdrachten.Rows(j).Item(3).ToString & vbCrLf & dttopdrachten.Rows(j).Item(4).ToString & vbCrLf & dttopdrachten.Rows(j).Item(5).ToString & vbCrLf & dttopdrachten.Rows(j).Item(6).ToString
dttAgenda.Rows(j).Item(i) = info
Next
Next
dgvAgenda.DataSource = dttAgenda
In the code above, I first count how many rows I have to make. Afterwards I add the amount of rows to the datatable (columns are added before). Until here it works, but then when I keep debugging I get the error. I tried googling but nothing could help me so far.
Seem problem has been solved without changing anything. So if someone want to make a calendar. Here's the solution ;)