Protected Sub grdView_PageIndexChanging(sender As Object, e As GridViewPageEventArgs) Handles grdView.PageIndexChanging
grdView.SelectedIndex = -1
grdView.PageIndex = e.NewPageIndex
' To persist DDL values at paging using datatable
Dim Data As New DataTable
Data.Columns.Add("RowIndex", Type.GetType("System.Int32"))
Data.Columns.Add("SelectedValue", Type.GetType("System.String"))
For Each Row As GridViewRow In grdView.Rows
Dim ddl As DropDownList = DirectCast(Row.FindControl("ddlSample"), ComboBox)
If ddl.SelectedValue <> "" Then
Dim Rows As DataRow = Data.NewRow
Rows("RowIndex") = Row.RowIndex
Rows("SelectedValue") = ddl.SelectedValue
Data.Rows.Add(Rows)
End If
Next
' Passing the datatable to session
Session("MYDataTable") = Data
grdView.DataSource = grdDataSource
grdView.DataBind()
If Session("MYDataTable") IsNot Nothing AndAlso Session("MYDataTable") IsNot DBNull.Value Then
Data = CType(Session("MYDataTable"), DataTable)
For Each row In Data.Rows
If e.NewPageIndex = row("PageIndex") Then
Dim ddl As DropDownList = DirectCast(grdView.Rows(row("RowIndex")).FindControl("ddlSample"), DropDownList)
ddl.SelectedValue = row("SelectedValue")
End If
Next
End If
The above Code is the code I'm having for Persisting DropDownList value but it is not working as expected.
In my GridView i have two Columns
Details of First column : I have list of employee names
Details of Second Column : It has a dropDownlist in each row with many items in it.
In my grid i have nearly 100 values, So i have set allowPaging="true" and have set pagesize="10".
The problem what I'm facing is
Step 1 : I'm selecting a value in dropdownlist of rowindex 2 in page 0
Step 2 : changing the page to 5, the value I selected in page 0 for the rowindex 2 also appears in the page 5 for the rowindex 2 as per my code.
But what i want is
Step 1 : I'm selecting a value in dropdownlist of rowindex 2 in page 0
Step 2 : changing the page to 5, no value should be selected as i haven't selected any values in it.
Step 3 : I i go back again to Page 0 the value of ddl in Rowindex 2 should have the previously selected value.
EDIT
I'm peristing the Values in Dictionary as mentioned here..!!
Dim ddlValues As New Dictionary(Of String, Integer)
For rowIndex As Integer = 0 To grdOnlineVoter.Rows.Count
Dim ddl As ComboBox = grdView.Rows(rowIndex).FindControl("ddlsample")
If ddl IsNot Nothing Then
If ddl.SelectedIndex > 0 Then
Dim ddlIndex As Integer = rowIndex
ddlValues.Add(ddl.SelectedValue, ddlIndex)
End If
End If
Next
But i'm unable to repopulate it to the Dropdownlist
Alright, based on what you have displayed here I have reached this conclusion.
You are saving the values to the Dictionary to the specific Row number. That is 0-9. However, row numbers does not take pagenumber into consideration. So I recommend you to do the following: (Change is on row 6)
Dim ddlValues As New Dictionary(Of String, Integer)
For rowIndex As Integer = 0 To grdOnlineVoter.Rows.Count
Dim ddl As ComboBox = grdView.Rows(rowIndex).FindControl("ddlsample")
If ddl IsNot Nothing Then
If ddl.SelectedIndex > 0 Then
Dim ddlIndex As Integer = rowIndex + (GridView1.PageIndex * 10)
ddlValues.Add(ddl.SelectedValue, ddlIndex)
End If
End If
Next
Now page 1 will have values: 0-9
Page 2 will have values 10-19 etc.
Related
I have two datagridview in a form. What I trying to do is
my datagridview1 has some rows and when i add same id row in datagridview2 then is should automatically convert datagridview1 checkbox to textbox when condition is matched because checkbox cannot disable in datagridview. how to do this?
Dim subCodeList As New List(Of String)
For i As Integer = 0 To DataGridView1.Rows.Count - 1
subCodeList.Add(DataGridView1.Rows(i).Cells(1).Value.ToString())
Next
For i As Integer = 0 To DataGridView2.Rows.Count - 1
If subCodeList.Contains(DataGridView2.Rows(i).Cells(16).Value.ToString()) Then
DataGridView1.Rows(i).Cells(0).Value = Nothing
DataGridView1.Rows(i).Cells(0) = New DataGridViewTextBoxCell()
DataGridView1.Rows(i).DefaultCellStyle.BackColor = Drawing.Color.Yellow
End If
Next
I have a data grid view where I need the columns to be frozen or fixed when scrolling vertically.
I have a data grid view control in vb.net windows application which displays the data in a parent-child hierarchy(as shown below). The first column displays the parent data and the second column displays all its child data. The child data in the second column can be as much as 100 rows or even more. So when scrolling down through the grid, the value in the first column does not remain there as it is while the values in the second column(i.e. the child data) scrolls down. So if the user wants to check to which parent, the current child info belongs to, then again he will have to scroll up to the starting of the column to find the name of the parent. I want the values in the first column to be displayed or frozen till it reaches the end of the list of its child values in the grid or at least till the next row where the next parent data starts. I have suggested the client to go with a tree view but they are not agreeing and need it in a data grid view itself. Is there anyway to achieve this in a data grid view?
Thanks in advance.
You can't freeze a row (in runtime, on dgv scrolling) with index greater than zero because all those before are frozen and at that point you can't scroll your datagridview.
If I understood correctly what you want I wrote this class quickly (probably should be optimized). Usage is simple.
1 - First create your own datagridview.
2 - then add your columns and rows (IMPORTANT: Put a “X” in the Tag in each row is a Parent or is considered as title for other rows as you seen in TestPopulate method) .
3 - Call the class I made by passing the datagridview (you created first) as a parameter. At this point this control takes its size, placement and REPLACE YOUR DATAGRIDVIEW .
Private Class CustomDgv
Inherits Panel
Dim WithEvents TopDgv As DataGridView = New DataGridView
Dim WithEvents DownDgv As DataGridView = New DataGridView
Dim Cols As Integer
' This variable is in case you have more rows as "headrow"
' In TestPopulate you can see how to get those
Dim listOfOwnerRows As List(Of Integer) = New List(Of Integer)
Dim currentTopRow As Integer = -1
Protected Overloads Property Height As Integer
Get
Return MyBase.Height
End Get
Set(value As Integer)
MyBase.Height = value
TopDgv.Height = TopDgv.RowTemplate.Height - 1
DownDgv.Height = value - TopDgv.Height - 1
End Set
End Property
Protected Overloads Property Width As Integer
Get
Return MyBase.Width
End Get
Set(value As Integer)
MyBase.Width = value
TopDgv.Width = value - 1
DownDgv.Width = value - 1
End Set
End Property
Sub New(dgvOriginal As DataGridView)
DownDgv = dgvOriginal
Dim parentCtrl As Control = dgvOriginal.Parent
parentCtrl.Controls.Remove(dgvOriginal)
parentCtrl.Controls.Add(Me)
Me.Location = DownDgv.Location
Me.Size = DownDgv.Size
Me.BorderStyle = DownDgv.BorderStyle
TopDgv.Width = Width - 2 - SystemInformation.VerticalScrollBarWidth
TopDgv.Height = TopDgv.RowTemplate.Height
TopDgv.ScrollBars = ScrollBars.None
TopDgv.ColumnHeadersVisible = False
TopDgv.BorderStyle = BorderStyle.None
DownDgv.ColumnHeadersVisible = False
DownDgv.BorderStyle = BorderStyle.None
TopDgv.Left = 0
DownDgv.Left = 0
DownDgv.Width = Width - 2
DownDgv.Height = Height - 2
For Each Col As DataGridViewColumn In DownDgv.Columns
Dim cIndex As Integer = TopDgv.Columns.Add(Col.Clone)
If Col.Frozen Then
TopDgv.Columns(cIndex).Frozen = True
End If
Cols += 1
Next
DownDgv.Top = 0
Me.Controls.Add(TopDgv)
Me.Controls.Add(DownDgv)
If DownDgv.Rows.Count > 0 Then
listOfOwnerRows = (From R As DataGridViewRow In DownDgv.Rows
Where R.Tag = "X"
Select R.Index).ToList
If listOfOwnerRows.Count > 0 Then
SetFrosenRow(listOfOwnerRows(0))
End If
End If
End Sub
Protected Sub SetFrosenRow(index As Integer)
If DownDgv.Rows.Count > index Then
TopDgv.Rows.Clear()
TopDgv.Rows.Add()
Dim currentRIndex As Integer = DownDgv.FirstDisplayedScrollingRowIndex
'If you want onlly the base row
For i As Integer = 0 To Cols - 1
TopDgv.Rows(0).Cells(i).Value = DownDgv.Rows(index).Cells(i).Value
Next
'Or else get the diplayed on top row
TopDgv.Rows(0).DefaultCellStyle = New DataGridViewCellStyle With {
.BackColor = Color.Bisque
}
currentTopRow = index
End If
End Sub
Protected Sub SetChildValuesInTopRow(index As Integer)
For i As Integer = 1 To Cols - 1
TopDgv.Rows(0).Cells(i).Value = DownDgv.Rows(index).Cells(i).Value
Next
End Sub
Private Sub DownDgv_Scroll(sender As Object, e As ScrollEventArgs) Handles DownDgv.Scroll
Try
If e.ScrollOrientation = ScrollOrientation.VerticalScroll Then
Dim topR As Integer = DownDgv.FirstDisplayedScrollingRowIndex
'If you want in top row the current value that is in the top uncomment this
SetChildValuesInTopRow(topR)
If listOfOwnerRows.Count > 0 Then
Dim rToSetAsOwner As Integer = listOfOwnerRows(listOfOwnerRows.Count - 1)
For i As Integer = listOfOwnerRows.Count - 1 To 0 Step -1
If listOfOwnerRows(i) <= topR Then
rToSetAsOwner = listOfOwnerRows(i)
Exit For
End If
Next
If rToSetAsOwner <> currentTopRow Then
SetFrosenRow(rToSetAsOwner)
End If
Console.WriteLine("rToSetAsOwner: " & rToSetAsOwner)
End If
Else
TopDgv.HorizontalScrollingOffset = DownDgv.HorizontalScrollingOffset
End If
Catch ex As Exception
Console.WriteLine(ex.ToString)
End Try
End Sub
End Class
Usage:
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
Try
' first populate you grid putting a tag in each row which is a header/parent/title for other rows
TestPopulate()
Dim customControl As Control = New CustomDgv(DataGridView1)
Catch ex As Exception
Console.WriteLine(ex.ToString)
End Try
End Sub
Sub TestPopulate()
For i As Integer = 0 To 100
DataGridView1.Rows.Add()
If i = 0 Then
DataGridView1.Rows.Item(0).Cells(0).Value = "Owner 0"
DataGridView1.Rows(0).Tag = "X"
End If
If i = 50 Then
DataGridView1.Rows.Item(50).Cells(0).Value = "Owner 50"
DataGridView1.Rows(50).Tag = "X"
End If
If i = 70 Then
DataGridView1.Rows.Item(70).Cells(0).Value = "Owner 70"
DataGridView1.Rows(70).Tag = "X"
End If
DataGridView1.Rows.Item(i).Cells(1).Value = "child_" & i.ToString & "_1"
DataGridView1.Rows.Item(i).Cells(2).Value = "child_" & i.ToString & "_2"
Next
End Sub
I hope I have been helpful
I have a datatable that I am adding records to in my windows forms application. this datatable only has 2 columns and the first column is the primary key and is an integer. The second column contains names and I need to automatically add a list of names from a listbox to the table. Most of these names will already have their own record in the table but there will be different names in the listbox each time. I need to check the existing record items against the listbox items to make sure no duplicates get added, but if there is a name in the listbox that does not exist in the datatable, add a new record for that name.
What I have tried so far is this:
Private m_cn As New SqlConnection()
Private m_DA As SqlDataAdapter
Private m_CB As SqlCommandBuilder
Private m_DataTable As New DataTable
Private m_IntRowPosition As Integer = 0
Private Sub btnInsertIntoDatabase_Click(sender As Object, e As EventArgs) Handles btnInsertIntoDatabase.Click
Dim drReadRow As DataRow = m_DataTable.NewRow()
Dim dcReadCol As DataColumn = m_DataTable.Columns.Item(1)
Dim intLoopCounter As Integer = 0
Dim unique As Boolean = True
If m_DataTable.Rows.Count = 0 Then
For m_IntRowPosition = 0 To (lstScannedNames.Items.Count() - 1)
Dim drNewRow As DataRow = m_DataTable.NewRow()
drNewRow("emp_id") = m_IntRowPosition
drNewRow("emp_name") = RTrim(lstScannedNames.Items.Item(RTrim(m_IntRowPosition)))
m_DataTable.Rows.Add(drNewRow)
Next m_IntRowPosition
GoTo SomeWhereElse
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
ElseIf m_DataTable.Rows.Count > 0 Then
For m_IntRowPosition = 0 To m_DataTable.Rows.Count
For intLoopCounter = 0 To lstScannedNames.Items.Count - 1
If RTrim(m_DataTable.Rows(m_IntRowPosition).Item(1)) = lstScannedNames.Items.Item(intLoopCounter) Then
unique = False
ElseIf RTrim(m_DataTable.Rows(m_IntRowPosition).Item(1)) <> lstScannedNames.Items.Item(intLoopCounter) Then
unique = True
lstScannedNames.SelectedIndex = intLoopCounter
intLoopCounter = lstScannedNames.Items.Count - 1
End If
Next intLoopCounter
If (unique) = True Then
Dim drNewRow As DataRow = m_DataTable.NewRow()
drNewRow("emp_id") = m_DataTable.Rows.Count()
drNewRow("emp_name") = lstScannedNames.Items.Item(lstScannedNames.SelectedIndex)
m_DataTable.Rows.Add(drNewRow)
Else
unique = True
End If
Next m_IntRowPosition
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
End If
SomeWhereElse:
m_DA.Update(m_DataTable)
MessageBox.Show("Operation Completed")
End Sub
The area of focus is the ElseIf statement. When I run this code and there are already records in the database, it adds the first name that is in the list and not in the datatable, to the datatable. It then adds the first name from the list to a new record, for each item in the list, which is about 20 times but it depends on the list length. I've been trying different things and I know I'm close but I've been stuck for a while.
Reverse your logic. Loop over the items in the listbox and check if they are present in the datatable
....
For intLoopCounter = 0 To lstScannedNames.Items.Count - 1
Dim name = lstScannedNames.Items.Item(intLoopCounter)
Dim rowExist = m_DataTable.Select("emp_name = '" & name & "'")
if rowExist Is Nothing OrElse rowExist.Length = 0 Then
Dim drNewRow As DataRow = m_DataTable.NewRow()
drNewRow("emp_id") = m_DataTable.Rows.Count()
drNewRow("emp_name") = name
m_DataTable.Rows.Add(drNewRow)
End If
Next m_IntRowPosition
...
Using the DataTable.Select method avoids to write an explicit loop to find the duplicate. And you can directly add the row when you are certain that there is no duplicate
i'm filling a list view with records from a datatable i need to limit the number of rows in the list view to 5 and when the records are more than 5 i need to create a new column in the list view to display the records...
that's how i'm filling the list view:
Private Sub ShowDataInLvw(ByVal data As DataTable, ByVal lvw As ListView)
lvw.View = View.Details
lvw.GridLines = True
lvw.Columns.Clear()
lvw.Items.Clear()
For Each col As DataColumn In data.Columns
lvw.Columns.Add(col.ToString)
Next
For Each row As DataRow In data.Rows
Dim lst As ListViewItem
lst = lvw.Items.Add(row(0))
For i As Integer = 1 To data.Columns.Count - 1
lst.SubItems.Add(row(i))
Next
Next
End Sub
note that my datatable has only 1 column and i'm using vb.net 2010
any help?
My datagridview is bound to a data table. I want to filter the datagridview without affecting data table. I know one way is to use bindingsource, but binding source will use column names in its filter. But I want to enable users to enter any string in a textbox to filter. So I pass datagridview by reference to a function PassFilter which removes unwanted rows in datagridview. I can see that it does execute rows removal in datagridview. But the problem is that when datagridview is shown on the form, it is unchanged, the same as the data table. I do not understand why rows are not removed on datagridview
The code is as follows:
DataGridView1.DataSource = table
PassFilter(DataGridView1, m_FilterQuick.strFilter.ToLower())
Private Sub PassFilter(ByRef datagridview As DataGridView, ByVal strFilter As String)
Dim i As Integer = 0
Dim j As Integer = 0
Dim containStr As Boolean = False
While i < datagridview.Rows.Count
j = 0
containStr = False
'If all cells in a row does not contain strFilter, delete this row from datagridview
While j < datagridview.Rows(i).Cells.Count
Dim c As DataGridViewCell = datagridview.Rows(i).Cells(j)
If Not c.Value Is DBNull.Value Or Nothing Then
If c.Value.ToString().ToLower().Contains(strFilter) Then
containStr = True
Exit While
End If
End If
j = j + 1
End While
If Not containStr Then
datagridview.Rows.RemoveAt(i)
End If
i = i + 1
End While
End Sub
Your big problem is that you're removing items in the DataGridViewRowCollection as you're iterating through that collection. Even if you're not getting an 'index out of range' error doing this you're going to end up removing the wrong row(s) as the index value of later rows change when you remove earlier rows.
What you should do is instead of removing rows in your row loop, add the row's index to a List(Of Integers).
After you're done iterating through all the rows in your DataGridView, Reverse() your list and use the row index values in your List to remove rows via the RemoveAt() method.
Here's what I mean:
Private Sub PassFilter(ByRef datagridview As DataGridView, ByVal strFilter As String)
Dim i As Integer = 0
Dim j As Integer = 0
Dim containStr As Boolean = False
' Row indexes we'll remove later on.
Dim deleteIndexList As List(Of Integer) = New List(Of Integer)
While i < datagridview.Rows.Count
j = 0
containStr = False
'If all cells in a row does not contain strFilter, delete this row from datagridview
While j < datagridview.Rows(i).Cells.Count
Dim c As DataGridViewCell = datagridview.Rows(i).Cells(j)
' Note: you'll want to enclose the tests for DBNull.Value and Nothing in parens like I show here.
If Not (c.Value Is DBNull.Value And c.Value Is Nothing) Then
If c.Value.ToString().ToLower().Contains(strFilter) Then
containStr = True
Exit While
End If
End If
j = j + 1
End While
If Not containStr Then
' Don't remove rows here or your row indexes will get out of whack!
' datagridview.Rows.RemoveAt(i)
deleteIndexList.Add(i)
End If
i = i + 1
End While
' Remove rows by reversed row index order (highest removed first) to keep the indexes in whack.
deleteIndexList.Reverse()
For Each idx As Integer In deleteIndexList
datagridview.Rows.RemoveAt(idx)
Next
End Sub
Are you displaying the data as read-only, or for edit?
If you're allowing the users to edit, can you find some way to hide the rows you don't want shown, rather than trying to remove them?
If you're displaying this as read-only, you could grab the data after the filtering, and throw it into a new datagridview.... (ugly, yes, but a possible option)
Oh wait... what about if you pass the datagridview by value instead of reference, so your changes at remove will be maintained?