I am converting data table content to string, Say the dataset has 12 rows and 8 column.
At the end, the Dict contain 12 rows or 96 columns. what's wrong with my code below, how do I reset the row?
Tia.
Dim ds As DataSet = ClsDB.GetDataSet(sql)
If Not ds Is Nothing AndAlso ds.Tables.Count > 0 Then
Dim row As New List(Of KeyValuePair(Of String, String))
Dim dict As New List(Of KeyValuePair(Of Integer, Object))
Dim dt As DataTable = ds.Tables(0)
Dim i As Integer = 0
For Each dr As DataRow In dt.Rows
For Each dc As DataColumn In dt.Columns
row.Add(New KeyValuePair(Of String, String)(dc.ColumnName, IIf(Not IsDBNull(dr.Item(dc.ColumnName)), dr.Item(dc.ColumnName), "")))
Next
dict.Add(New KeyValuePair(Of Integer, Object)(i, row))
i += i
Next
Return New JavaScriptSerializer().Serialize(dict)
Else
Return "No Data"
End If
You should reinitialise row for every dr, in fact you needn't declare row outside the dr loop.
For Each dr As DataRow In dt.Rows
Dim row As New List(Of KeyValuePair(Of String, String)) // <<-
For Each dc As DataColumn In dt.Columns
row.Add(...
Next
dict.Add(...
Next
Related
i have a function getSelectedNumbers that take as input 3 list of number. after a manipulation i need to obtain a string in the format
"[1_3,10,20,30,500],[1_1,2],[]"
if the list is empty i need to have in the string the "[]" char
i wrote the below function but i need to manage the empty case.
Based on comment of Anu6is :
i was able to rewrite my code as below
'''vb
Public Function getSelectedNumbers() As String
Dim selectedNumbers1 As IList(Of Element) = repo.CanvasTerminalProduct.BoardDetails.Panel.pnlSuper3Panel1.Find(".//div[#class='selected']")
Dim selectedNumbers2 As IList(Of Element) = repo.CanvasTerminalProduct.BoardDetails.Panel.pnlSuper3Panel2.Find(".//div[#class='selected']")
Dim selectedNumbers3 As IList(Of Element) = repo.CanvasTerminalProduct.BoardDetails.Panel.pnlSuper3Panel3.Find(".//div[#class='selected']")
Dim list1 As New List(Of String)
Dim list2 As New List(Of String)
Dim list3 As New List(Of String)
For i As Integer = 0 To selectedNumbers1.Count -1
list1.Add(selectedNumbers1(i).GetAttributeValue("innerText").ToString)
Next i
For i As Integer = 0 To selectedNumbers2.Count -1
list2.Add(selectedNumbers2(i).GetAttributeValue("innerText").ToString)
Next i
For i As Integer = 0 To selectedNumbers3.Count -1
list3.Add(selectedNumbers3(i).GetAttributeValue("innerText").ToString)
Next i
'Create List of List
Dim selectedNumbersList As New List(Of List(Of String)) From {list1, list2, list3}
Dim builder As New StringBuilder 'Used to build the output
'Convert all the list in the correct string format using the join
For Each listX As List(Of String) In selectedNumbersList
builder.Append("[1_").Append(String.Join(",", listX)).Append("],") 'String.Join() give you a comma delmited string
Next
'Remove the last, and the [1_] that are not needed
Dim strSelectedNunmber As String = builder.ToString().TrimEnd(","c)
strSelectedNunmber = strSelectedNunmber.ToString().Replace("[1_]","[]")
Return str
End Function
'''
now my question is there is a better way to generate the list1 list2 list3 ?
This is assuming that Element is simply an Integer
Public Function getSelectedNumbers() As String
Dim selectedNumbers1 As New List(Of Integer) From {20, 30, 500, 10, 3} 'Unordered list
Dim selectedNumbers2 As New List(Of Integer) From {1, 2, 500} 'Ordered list
Dim selectedNumbers3 As New List(Of Integer) 'empty list
Dim selectedNumbersList As New List(Of List(Of Integer)) From {selectedNumbers1, selectedNumbers2, selectedNumbers3}
Dim builder As New StringBuilder 'Used to build the output
For Each list In selectedNumbersList
list.Sort() 'Sort your list
builder.Append("[").Append(String.Join(",", list)).Append("],") 'String.Join() give you a comma delmited string
Next
Return builder.ToString.TrimEnd(","c) 'Remove the final comma (,) and return the formatted string
End Function
[3,10,20,30,500],[1,2,500],[]
Does this work for you?
Dim selectedNumbers1 As New List(Of Integer) From {20, 30, 500, 10, 3}
Dim selectedNumbers2 As New List(Of Integer) From {1, 2, 500}
Dim selectedNumbers3 As New List(Of Integer)
'either make 3 loops or 1, but you have to make a list of lists first
Dim selectedNumbersList As New List(Of List(Of Integer)) From {selectedNumbers1, selectedNumbers2, selectedNumbers3}
For Each listX In selectedNumbersList
listX.Sort()
Dim ReturnString As String = "["
If listX.Count > 0 Then
For Each itemvalue In listX
ReturnString &= itemvalue & ","
Next
ReturnString = ReturnString.Remove(ReturnString.Length - 1)
End If
ReturnString &= "]"
Debug.Print(ReturnString)
Next
'[3,10,20,30,500]
'[1,2,500]
'[]
I need a function that returns a datatable, from any arraylist (2 dimensions) as arguments? Thanks for your help
Creating two dimensional Arraylist:
Public Overrides Function Find(Optional ByRef conditions As ArrayList = Nothing) As System.Collections.ArrayList
Dim collection As New ArrayList
Dim cmd ......... ' Select command based on an arraylist of conditions
Dim dr As SqlDataReader = cmd.ExecuteReader()
While dr.Read()
Dim cnt As New contact
cnt .Id() = dr("id")
cnt .Name= dr("name")
'......... other columns are imported
collection.Add(cnt )
End While
dr.Close()
Return collection
End Function
Suitable solution found:
Public Shared Function ArrayListToDataTable(ByVal arraylist1 As ArrayList) As System.Data.DataTable
Dim dt As New System.Data.DataTable()
For i As Integer = 0 To arraylist1.Count - 1
Dim GenericObject As Object = arraylist1.Item(i)
Dim NbrProp As Integer = GenericObject.GetType().GetProperties().Count
For Each item As PropertyInfo In GenericObject.GetType().GetProperties()
Try
Dim column = New DataColumn()
Dim ColName As String = item.Name.ToString
column.ColumnName = ColName
dt.Columns.Add(column)
Catch
End Try
Next
Dim row As DataRow = dt.NewRow()
Dim j As Integer = 0
For Each item As PropertyInfo In GenericObject.GetType().GetProperties()
row(j) = item.GetValue(GenericObject, Nothing)
j += 1
Next
dt.Rows.Add(row)
Next
Return dt
End Function
After 2 years, Let me answer this=>
Function ConvertArrayListToDataTable(ByVal arraylist As ArrayList) As DataTable
Dim dt As DataTable = New DataTable()
If arraylist.Count <= 0 Then
Return dt
End If
Dim propertiesinfo As PropertyInfo() = arraylist(0).GetType().GetProperties()
For Each pf As PropertyInfo In propertiesinfo
Dim dc As DataColumn = New DataColumn(pf.Name)
dc.DataType = pf.PropertyType
dt.Columns.Add(dc)
Next
For Each ar As Object In arraylist
Dim dr As DataRow = dt.NewRow
Dim pf As PropertyInfo() = ar.GetType().GetProperties()
For Each prop As PropertyInfo In pf
dr(prop.Name) = prop.GetValue(ar, Nothing)
Next
dt.Rows.Add(dr)
Next
Return dt
End Function
i'm in VS2008 Studio, i have this datagridview with multiple columns which the last column contains a date and time value.
lot's of rows are pretty the same except by they're date column.
what i wanted to do is to trim the whole datagridview duplicate rows except they're most recent ones based on they're date column.
i have sth like this:
Administrator,192.168.137.221,2,file://C:\WMPub\WMRoot\industrial.wmv , 07.Jul.2014 - 23:11:59
Administrator,192.168.137.221,2,file://C:\WMPub\WMRoot\industrial.wmv , 07.Jul.2014 -
21:11:59
Administrator,192.168.137.221,2,file://C:\WMPub\WMRoot\industrial.wmv , 07.Jul.2014 - 22:11:59
Administrator,192.168.137.221,2,file://C:\WMPub\WMRoot\industrial.wmv , 07.Jul.2014 - 20:11:59
Administrator,192.168.137.221,2,file://C:\WMPub\WMRoot\industrial.wmv , 07.Jul.2014 - 11:11:59
Everyone ,192.168.137.221,2,file://C:\WMPub\WMRoot\industrial.wmv , 07.Jul.2014 - 17:11:59
Everyone ,192.168.137.221,2,file://C:\WMPub\WMRoot\industrial.wmv , 07.Jul.2014 - 14:11:59
the output i want should be like this:
Administrator 192.168.137.221 2 file://C:\WMPub\WMRoot\industrial.wmv 07.Jul.2014 - 23:11:59
Everyone 192.168.137.201 2 file://C:\WMPub\WMRoot\industrial.wmv 07.Jul.2014 - 17:11:59
....
please consider "," as column seprators! (i dont know how to draw a table here, sorry again)!
i have this snippet that trim the duplicate lines in a datagridview but it lacks preserving the latest entry:
Public Function RemoveDuplicateRows(ByVal dTable As DataTable, ByVal colName As String) As DataTable
Dim hTable As New Hashtable()
Dim duplicateList As New ArrayList()
For Each dtRow As DataRow In dTable.Rows
If hTable.Contains(dtRow(colName)) Then
duplicateList.Add(dtRow)
Else
hTable.Add(dtRow(colName), String.Empty)
End If
Next
For Each dtRow As DataRow In duplicateList
dTable.Rows.Remove(dtRow)
Next
Return dTable
End Function
what should i do?
thanks in advance
Here is some code that illustrates the approach:
Dim dict As New dictionary(Of String, DataRow)
For Each dtRow As DataRow In dTable.Rows
Dim key As String = dtRow("column1") + "," + dtRow("column2") ' + etc.
Dim dictRow As DataRow = Nothing
If dict.TryGetValue(key, dictRow) Then
'check and update date
'you can skip this part, if your data is sorted
If dtRow("dateColumn") > dictRow("dateColumn") Then
dictRow("dateColumn") = dtRow("dateColumn")
End If
Else
dict.Add(key, dtRow)
End If
Next
In the end dict contains the rows you need, you can get them via dict.Values.ToArray()
EDIT: I found the error - dictRow should be dtRow in the above code (now fixed). Then it should work. Here is a full version of self contained example (console app), since I wrote it anyway - focus on RemoveDuplicates, the rest is just prepwork:
Sub Main()
Dim dt As New DataTable
With dt.Columns
.Add("PublishingPoint")
.Add("Username")
.Add("IP")
.Add("Status")
.Add("Req URL")
.Add("Last seen", GetType(Date))
End With
'this populates the initial data table, use your method
Dim _assembly As Assembly = Assembly.GetExecutingAssembly()
Dim _textStreamReader As New StreamReader(_assembly.GetManifestResourceStream("ConsoleApplication16.data.csv"))
While Not _textStreamReader.EndOfStream
Dim sLine As String = _textStreamReader.ReadLine().TrimEnd
If String.IsNullOrEmpty(sLine) Then Exit While
Dim values() As String = sLine.Split(",")
Dim newRow As DataRow = dt.NewRow
For iColumnIndex As Integer = 0 To dt.Columns.Count - 1
Dim columnName As String = dt.Columns(iColumnIndex).ColumnName
newRow.Item(columnName) = values(iColumnIndex)
Next
dt.Rows.Add(newRow)
End While
Console.WriteLine("Old count: " & dt.Rows.Count)
Dim newDt As DataTable = RemoveDuplicates(dt, "Last seen")
Console.WriteLine("New count: " & newDt.Rows.Count)
Console.ReadLine()
End Sub
Private Function RemoveDuplicates(dt As DataTable, colName As String) As DataTable
Dim keyColumnNames As New List(Of String)
Dim exceptColumnsHash As New HashSet(Of String)({colName})
For Each col As DataColumn In dt.Columns
Dim columnName As String = col.ColumnName
If Not exceptColumnsHash.Contains(col.ColumnName) Then
keyColumnNames.Add(columnName)
End If
Next
Dim dict As New Dictionary(Of String, DataRow)
For Each dtRow As DataRow In dt.Rows
Dim keyColumnValues As New List(Of String)
For Each keyColumnName In keyColumnNames
keyColumnValues.Add(dtRow.Item(keyColumnName))
Next
Dim key As String = String.Join(",", keyColumnValues)
Dim dictRow As DataRow = Nothing
If dict.TryGetValue(key, dictRow) Then
If dtRow(colName) > dictRow(colName) Then
dictRow(colName) = dtRow(colName)
End If
Else
dict.Add(key, dtRow)
End If
Next
Dim dtReturn As DataTable = dt.Clone
For Each dtRow As DataRow In dict.Values
dtReturn.ImportRow(dtRow)
Next
Return dtReturn
End Function
To make this code run, you need to manually add a file to the project and set build action to "Embedded resource".
I have a DataRow. Is there a way to convert it into an arraylist? I need to convert it to an arraylist because I want to pass it to a function which compares two arrays and returns false if they are not the same.
foo(datarow, arraylist)
Public Function foo(ByVal arr1 as Arraylist, ByVal arr2 as ArrayList) as Boolean
Compare and return false if they are not the same
End Function
So, how do I convert datarow to arraylist so that I can pass it to that function.
I agree that you should only convert to ArrayList if necessary, but you certainly can.
Dim al As New ArrayList
Dim dt As New DataTable
dt.Columns.Add("f")
dt.Columns.Add("n")
Dim dr As DataRow
dr = dt.NewRow
dr.Item(0) = "First"
dr.Item(1) = "Name"
dt.Rows.Add(dr)
For Each row As DataRow In dt.Rows
For Each column As DataColumn In dt.Columns
al.Add(row.Item(column.ColumnName))
Next
MessageBox.Show(al.Item(0).ToString & " " & al.Item(1).ToString)
Next
In vb.net If I have HashTable,key is integer and the value is a list of integers, how to append integers to the value of a given key,
I have tried it but each time I found the integer last added only, (the list only has the last item added).
Here is my code , where dt is DataTable object
Dim dt = report.getEvaluationReportByObjectiveGroupId(29)
Dim data As New Hashtable()
Dim dataEntry As DictionaryEntry
Dim res As String
For Each row As DataRow In dt.Rows
Dim strYear = row.Item("Year")
Dim strData = row.Item("EmpCount")
If data.ContainsKey(strYear) Then
Dim newCountArr As List(Of Int32) = DirectCast(data(strYear), List(Of Int32))
' newCountArr.AddRange(data(strYear))
newCountArr.Add(strData)
' data.Remove(strYear)
' data.Add(strYear, newCountArr)
Else
Dim countArr As New List(Of Integer)
countArr.Add(strData)
data.Add(strYear, countArr)
End If
' data.Add(strYear, strData)
Next row
I would suggest to use the strongly typed Dictionary(Of Int32, List(Of Int32)) instead, it works similar. But anyway, here's the HashTable approach:
Dim table = New Hashtable
Dim list = New List(Of Int32)
For i = 1 To 999
list.Add(i)
Next
table.Add(1, list)
' somewhere else you want to read the list for a given key (here 1) '
Dim list1 As List(Of Int32) = DirectCast(table(1), List(Of Int32))
list.Add(1000) ' add another integer to the end of the list '
' note: you don't need to add the list to the HashTable again '
Edit: Since you've posted your code, here's the corrected:
For Each row As DataRow In dt.Rows
Dim strYear = row.Field(Of Int32)("Year")
Dim strData = row.Field(Of Int32)("EmpCount")
Dim list As List(Of Int32)
If data.ContainsKey(strYear) Then
list = DirectCast(data(strYear), List(Of Int32))
Else
list = New List(Of Int32)
data.Add(strYear, list)
End If
list.Add(strData)
Next row