Sort Alphanumeric DataView Column - vb.net

My DataGridView's DataSource is bound to a DataView. The DataView is equal to my dtBills DataTable. Like so:
Dim View As New DataView
View.Table = DataSet1.Tables("dtBills")
dgvBills.DataSource = View
I have multiple columns in this DataGridView. One in particular has strings and integers as information. When I click on the DataGridView Column Header to sort the column, it sorts as strings like the column on the left:
'Curr Col >>> ' Wanted Result
10001 >>> 10001
100012 >>> 11000
11000 >>> 12000
110049 >>> 100012
12000 >>> 110049
E-1234 >>> E-1234
T-12345 >>> T-1235
T-1235 >>> T-12345
How would I go about sorting a bound DataGridView Column when pressing on the Column Header as I normally would? Should I use my DataView to help me out?

When a DataGridView is databound it is not possible to use its sorting and it is necessary to sort source data. The sorting is a bit complicated so I need two helper columns.
dgvBills.AutoGenerateColumns = False
tbl.Columns.Add(New DataColumn("Scol1", GetType(String)))
tbl.Columns.Add(New DataColumn("Scol2", GetType(Integer)))
The first one will contain a leading letters (or empty string). The second will contain only a number contained in the string. We will sort by Scol1, Scol2.
Now we set all comumns to Programatic mode (DataGridViewColumnSortMode Enumeration)
For Each column As DataGridViewColumn In dgvBills.Columns
column.SortMode = DataGridViewColumnSortMode.Programmatic
Next
And custom sorting is achieved in a handler of ColumnHeaderMouseClick (DataGridView.Sort Method (IComparer)). We will use sorting of the underlying view instead of the Grid sorting.
Private Sub dgvBills_ColumnHeaderMouseClick(sender As Object, e As System.Windows.Forms.DataGridViewCellMouseEventArgs) Handles dgvBills.ColumnHeaderMouseClick
Dim newColumn As DataGridViewColumn = dgvBills.Columns(e.ColumnIndex)
Dim direction As ListSortDirection
Dim Modifier As String = ""
If newColumn.HeaderCell.SortGlyphDirection = SortOrder.Ascending Then
direction = ListSortDirection.Descending
Modifier = " desc"
Else
direction = ListSortDirection.Ascending
End If
Dim View As DataView = dgvBills.DataSource
If {"JobNumber", "JobNumber1"}.Contains(dgvBills.Columns(e.ColumnIndex).Name) Then
View.Table.Columns("Scol2").Expression = String.Format("Convert(iif (substring({0},1,2) like '*-',substring({0},3,len({0})-1),{0}), 'System.Int32')", dgvBills.Columns(e.ColumnIndex).Name)
View.Table.Columns("Scol1").Expression = String.Format("iif (substring({0},1,2) like '*-',substring({0},1,2),'')", dgvBills.Columns(e.ColumnIndex).Name)
View.Sort = String.Format("Scol1 {0},Scol2 {0}", Modifier)
Else
dgvBills.Sort(newColumn, direction)
End If
If direction = ListSortDirection.Ascending Then
newColumn.HeaderCell.SortGlyphDirection = SortOrder.Ascending
Else
newColumn.HeaderCell.SortGlyphDirection = SortOrder.Descending
End If
End Sub
In {"JobNumber", "JobNumber1"}.Contains ... is possible to set columns which are sorted differntly. Other columns are sorted as the Grid sorts them by default or it is possible to create another custom sorting.
Note: I have fully working example but I hope that fragments are good enough.

The column is sorted correctly as strings and I suppose you want to sort it as numbers. The problem is that it seems that the strings you have combine numbers and characters. The result is necessity rather complex sorting for a DataView.
Dim tbl As New DataTable("dtBills")
Dim DataSet1 As New DataSet
DataSet1.Tables.Add(tbl)
tbl.Columns.Add(New DataColumn("MyCol", GetType(String)))
Dim vals As String() = {"10001", "100012", "11000", "110049", "12000", "E-1234", "T-12345", "T-1235"}
For qq = 0 To vals.Length - 1
Dim row As DataRow
row = tbl.NewRow
row(0) = vals(qq)
tbl.Rows.Add(vals(qq))
Next
tbl = DataSet1.Tables("dtBills")
tbl.Columns.Add(New DataColumn("Scol2", GetType(Integer)) With {.Expression = "Convert(iif (substring(MyCol,1,2) like '*-',substring(MyCol,3,len(MyCol)-1),MyCol), 'System.Int32')"})
tbl.Columns.Add(New DataColumn("Scol1", GetType(String)) With {.Expression = "iif (substring(MyCol,1,2) like '*-',substring(MyCol,1,2),'')"})
Dim View As New DataView(tbl)
View.Sort = "Scol1,Scol2"
View.Table = DataSet1.Tables("dtBills")
So two new columns are added. The first maintain sorting by initial letters the second to enable sorting by the number contained in the a string.

Related

First row as header in datagridview

Imported data from CSV to datagridview has header in first row, I could hide that row and name header for every column, problem is that data table has 68 columns. Is it possible to make first row header without having to do that manually for every single column?
Your datagrid should have taken all column names from CSV, if not then you need to have a look at this great article. It will help you a lot. This is the link.
After experimenting and help from user: ooopsoft :
Dim TextFieldParser1 As New Microsoft.VisualBasic.FileIO.TextFieldParser(receiveStream)
TextFieldParser1.Delimiters = New String() {","}
Dim newline() As String = TextFieldParser1.ReadFields()
While Not TextFieldParser1.EndOfData
Dim Row1 As String() = TextFieldParser1.ReadFields()
If DataGridView1.Columns.Count = 0 AndAlso Row1.Count > 0 Then
Dim i As Integer
For i = 0 To Row1.Count - 1
DataGridView1.Columns.Add(newline(i), newline(i))
Next
End If
End While

Editing Datable before binding to listview in vb.net

hi this is my code to get datable from query but i need to check for some values like if there is 0 in any column then replace it with N.A.
Dim op As New cad
Dim dt As DataTable = op.Fetchbooks().Tables(0)
Dim sb As New StringBuilder()
Dim rp As System.Data.DataRow
If dt.Rows.Count > 0 Then
ListView1.DataSource = dt
ListView1.DataBind()
DropDownList1.DataSource = dt
DropDownList1.DataTextField = "Description"
DropDownList1.DataValueField = "Description"
DropDownList1.DataBind()
End if
so is there any way to check some values and edit in datable before binding ???
First, if possible i would modify your sql-query in Fetchbooks instead to replace 0 with N.A.. I assume you are querying the database.
However, if you want to do it in memory:
For Each row As DataRow In dt.Rows
For Each col As DataColumn In dt.Columns
If row.IsNull(col) OrElse row(col).ToString = "0" Then
row(col) = "N.A."
End If
Next
Next
Sure: you can iterate through the table, making whatever value replacements are appropriate (assuming that your replacement values are type-compatible with what came from the query).
Something like:
For Each row as DataRow in dt.Rows
if row("columnname") = "left" then
row("columnname") = "right"
Next
Then bind it to the grid, and you should see your updated values.
Once you have the DataTable object you can manipulate it as you need:
For Each rp In dt.Select("COLUMN_A = '0'")
rp("COLUMN_A") = "N.A."
Next
Note that this assumes that COLUMN_A is defined as a string type, not a numeric.
The challenge will be if you intend on saving this data back to it's source and you don't want the original 0 value to be saved instead of N.A.. You could add dt.AcceptChanges immediately after the above loop so that it will appear as the Fetchbooks query had these values all along.

Adding two column values to listbox in vb.net

I have a table named users which has the following columns in it
User_id,user_name,user_pwd,First_Name,Middle_Name,Last_Name and user_type.
I have dataset named dst and created a table called user in the dataset. Now I want to populate listbox with user_Name, First_Name, Last_name of each and every row in the table user.
I am able to add one column value at a time but not getting how to add multiple column values of each row to listbox
Dim dt As DataTable = Dst.Tables("user")
For Each row As DataRow In dt.Rows
lstUsers.Items.Add(row("User_Name"))
Next
Above code works perfectly but I also want to add First_name as well as last_name to the list box at the same time.
Use same approach as you have, but put all values you want in one string.
Dim dt As DataTable = Dst.Tables("user")
For Each row As DataRow In dt.Rows
Dim sItemTemp as String
sItemTemp = String.Format("{0},{1},{2}", row("User_Name"), row("First_Name"), row("Last_Name"))
lstUsers.Items.Add(sItemTemp)
Next
String.Format() function will call .ToString() on all parameters.
In this case if row(ColumnName) is NULL value then .ToString() return just empty string
You have 2 choices:
Using the ListBox:
To use the ListBox, set the font to one that is fixed width like courier new (so that the columns line up), and add the items like this:
For Each row As DataRow In dt.Rows
lstUsers.Items.Add(RPAD(row("User_Name"),16) & RPAD(row("First_Name"),16) & RPAD(row("Last_Name"),16))
Next
The RPAD function is defined like this:
Function RPAD(a As Object, LENGTH As Object) As String
Dim X As Object
X = Len(a)
If (X >= LENGTH) Then
RPAD = a : Exit Function
End If
RPAD = a & Space(LENGTH - X)
End Function
Adjust the LENGTH argument as desired in your case. Add one more for at least one space. This solution is less than ideal because you have to hard-code the column widths.
Use a DataGridView control instead of a ListBox. This is really the best option, and if you need, you can even have it behave like a ListBox by setting the option to select the full row and setting CellBorderStyle to SingleHorizontal. Define the columns in the designer, but no need to set the widths - the columns can auto-size, and I set that option in the code below. if you still prefer to set the widths, comment out the AutoSizeColumnsMode line.
The code to set up the grid and add the rows goes like this:
g.Rows.Clear() ' some of the below options are also cleared, so we set them again
g.AutoSizeColumnsMode = DataGridViewAutoSizeColumnMode.AllCells
g.CellBorderStyle = DataGridViewCellBorderStyle.SingleHorizontal
g.SelectionMode = DataGridViewSelectionMode.FullRowSelect
g.AllowUserToAddRows = False
g.AllowUserToDeleteRows = False
g.AllowUserToOrderColumns = True
For Each row As DataRow In dt.Rows
g.Rows.Add(row("User_Name"), row("First_Name"), row("Last_Name"))
Next
You might solved your problem by now but other users like me might have issue with it.
Above answers given worked for me even but I found a same answer in a simple way according to what I want..
cmd = New SqlCommand("select User_Name, First_Name, Last_Name from User")
Dim dr As SqlDataReader = cmd.ExecuteReader(YourConnectionString)
If dr.HasRows Then
Do While dr.Read
lst.Items.Add(dr.Item(0).ToString & " " & dr.Item(1).ToString & " " & dr.Item(2).ToString)
Loop
End If
This worked for me, maybe wrong way but I found it simple :)
May I suggest you use a ListView control instead of Listbox?
If you make the switch, here's a sample subroutine you could use to fill it up with the data you said you want. Adapt it the way you like; there's much room for improvement but you get the general idea:
Public Sub FillUserListView(lstUsers As ListView, Dst As DataSet)
Dim columnsWanted As List(Of String) = New List(Of String)({"User_Name", "First_Name", "Last_Name"})
Dim dt As DataTable = Dst.Tables("user")
Dim columns As Integer = 0
Dim totalColumns = 0
Dim rows As Integer = dt.Rows.Count
'Set the column titles
For Each column As DataColumn In dt.Columns
If columnsWanted.Contains(column.ColumnName) Then
lstUsers.Columns.Add(column.ColumnName)
columns = columns + 1
End If
totalColumns = totalColumns + 1
Next
Dim rowObjects(columns - 1) As ListViewItem
Dim actualColumn As Integer = 0
'Load up the rows of actual data into the ListView
For row = 0 To rows - 1
For column = 0 To totalColumns - 1
If columnsWanted.Contains(dt.Columns(column).ColumnName) Then
If actualColumn = 0 Then
rowObjects(row) = New ListViewItem()
rowObjects(row).SubItems(actualColumn).Text = dt.Rows(row).Item(actualColumn)
Else
rowObjects(row).SubItems.Add(dt.Rows(row).Item(actualColumn))
End If
lstUsers.Columns.Item(actualColumn).Width = -2 'Set auto-width
actualColumn = actualColumn + 1
End If
Next
lstUsers.Items.Add(rowObjects(row))
Next
lstUsers.View = View.Details 'Causes each item to appear on a separate line arranged in columns
End Sub

How to Implement Rowspan in a GridView (for .NET 3.5)

I created a custom GridView (actually a RadGrid) which does roughly the following.
Initialize GridView formatting
Setup Columns (depending on type of data to be displayed)
Populate the rows
When Instantiating this GridView, and adding it to my page, I want the first column to contain a "rowspan" attribute on the first row of repeated, but similar data. The "rowspan" value should be equal to the number of similar rows following it. In this way I hope to make the final view cleaner.
The logic for this, I figure, should take place while populating the rows. Initially I add rows to a DataTable and then bind it to the GridView as the final step.
Here's the general logic I was attempting, but it didn't work for me. What am I doing wrong?
Dim dt As New DataTable() 'Has three default columns
For Each d In Documents 'MAIN ITEM (First Column Data)
Dim rowspan As Integer
rowspan = 0
For Each f In Files
If rowspan = 0 Then
Me.dt.Rows.Add(New Object() {d.Title, f.Language, f.FileSize})
'THIS DOESN'T WORK!
Me.dt.Columns(0).ExtendedProperties.Item("rowspan") = rowspan.ToString()
Else
Me.dt.Rows.Add(New Object() {Nothing, f.Language, f.FileSize})
End If
rowspan += 1
Next
Next
Also keep in mind that the this is dumped into a DataView which is sorted by the first column, so I would imagine it must actually be sorted first, then somehow count the rows for each "like" first column, then set the "rowspan" value for the first row of that column equal to the number of rows belonging to it.
Does this make sense? Here is an ideal example of what I would like to accomplish in the layout:
Try this.
Protected Sub DemoGrid_PreRender(sender As Object, e As System.EventArgs) Handles DemoGrid.PreRender
MergeRowsWithSameContent(sender)
End Sub
Public Sub MergeRowsWithSameContent(gvw As GridView)
For rowIndex As Integer = gvw.Rows.Count - 2 To 0 Step -1
Dim row As GridViewRow = gvw.Rows(rowIndex)
Dim previousRow As GridViewRow = gvw.Rows(rowIndex + 1)
For i As Integer = 0 To row.Cells.Count - 1
If row.Cells(i).Text = previousRow.Cells(i).Text Then
row.Cells(i).RowSpan = If(previousRow.Cells(i).RowSpan < 2, 2, previousRow.Cells(i).RowSpan + 1)
previousRow.Cells(i).Visible = False
End If
Next
Next
End Sub
P.S: Shameless port of this wonderful code I have been using for years.

Changing DataGridView Column Properties in VB Code

So I'm adding columns in the code, rather than design view...
frmMain.dgv_test.Columns.Add("col1", "1")
frmMain.dgv_test.Columns.Add("col2", "2")
'etc
How do I edit properties such as Column Width, Frozen, and all the other properties that can be seen in the design view if I were to "design" a column?
Thank you.
Create a new Temp DataGridColumn then set all the properties you want for that column and then add it to the grid.
Dim tempC as new DataGridColumn()
tempC.HeaderText ="col1"
tempC.HeaderStyle.whatever
etc....
...then
frmMain.dgv_test.Collumns.Add(tempC)
http://msdn.microsoft.com/en-us/library/2wfbzezz%28v=VS.100%29.aspx
The DataGridViewColumnCollection.Add method actually returns the index of the added DataGridViewColumn, so you can also do this:
Dim colIndex As Integer = frmMain.dgv_test.Columns.Add("col1", "1")
Dim col As DataGridViewColumn = frmMain.dgv_test.Columns(colIndex)
col.Width = 100
col.Frozen = True
Or here's another, less verbose way:
With frmMain.dgv_test.Columns
Dim col As DataGridViewColumn = .Item(.Add("col1", "1"))
col.Width = 100
col.Frozen = True
End With
And so on.