I am working in VB.NET and have a datagridview with multiple columns, the first being a checkboxcolumn. I want to add the functionality to restrict the amount of rows the user can select. For example, I may have 10 rows of entries in the datagridview but want to only allow for 5 checkboxes to be checked. Does anyone have any ideas on how to go about this?
You can use the readonly property of datagridview to prevent the edit.and use a for loop to limit which all rows to be disabled.
for i=5 to datagridview1.rows.count-1
dataGridView1.Rows[i].Cells[columnindex].ReadOnly = true;
next
Specify the index of column to disable at column index.this code will disable editing of 6th to last row of datagridview.
You can Maintain States of CheckBoxes in ViewState and Then Check Length of Array List which Gives You No of Items Checked
Dim CheckBoxArray As ArrayList
If ViewState("CheckBoxArray") IsNot Nothing Then
CheckBoxArray = DirectCast(ViewState("CheckBoxArray"), ArrayList)
Else
CheckBoxArray = New ArrayList()
End If
Add or Remove items From ViewState
If chkAll.Checked Then
If CheckBoxArray.IndexOf(checkAllIndex) = -1 Then
CheckBoxArray.Add(checkAllIndex)
End If
Else
If CheckBoxArray.IndexOf(checkAllIndex) <> -1 Then
CheckBoxArray.Remove(checkAllIndex)
CheckAllWasChecked = True
End If
End If
Related
I have a datagrid view with 10 columns. It includes 2 checkbox columns followed by a combobox and then a number of text boxes for data entry. I do not have a database to load the combobox drop down but I do have a variable with 19 rows. I have tried a number of methods from SO but haven't been able to get this to work correctly so I can load the combobox for the user to select a value.
The code I've been using is like this. I have tried several different ways that are commented out as well...
' Build datagridview row
'
Dim t1 As New DataTable
For Each col As DataGridViewColumn In dgvMultiSelect.Columns
t1.Columns.Add(col.HeaderText)
Next
Dim dgvcb As New DataTable
dgvcb.Columns.Add("RunID", GetType(String))
For el = 0 To sRunID.Length - 1
dgvcb.Columns.Add(sRunID(el))
RunID.Items.Add(sRunID(el))
Next
' RunID.DataSource = dgvcb
' RunID.DataPropertyName = "dgvcb"
' RunID.DataSource = sRunID
' RunID.DataPropertyName = "sRunID"
'Dim chk As New DataGridViewCheckBoxColumn()
'DataGridView1.Columns.Add(chk)
'chk.HeaderText = "Check Data"
'chk.Name = "chk"
dgvMultiSelect.Rows(0).Cells(0).Value = True
The checkbox works fine (it shows as checked) and I was able to set the combobox value to show but clicking on the dropdown does nothing. I believe the data is in RunID (the column in the dgv.
Well, the answer that worked for me is: I was referencing the datagridviewCOLUMN and not a datagridviewCOMBOBOXcolumn. Thanks to Sai Kalyan Kumar Akshinthala!
' Build datagridview row
Dim dgvcc As DataGridViewComboBoxColumn
dgvcc = dgvMultiSelect.Columns("RunID")
For el = 0 To sRunID.Length - 1
dgvcc.Items.Add(sRunID(el))
dgvMultiSelect.Rows(0).Cells(2).Value = sRunID(el)
Next
Maybe next time you'll try to understand before voting down. Such a silly thing this voting down anyway. It should not reduce reputation.
I've checked for hours but I can't seem to find anything to help.
I want to loop through tables and columns from a dataset and use the column name in a combobox.items.add() line, however the eventual goal is to fill the combobox from the dataset itself possibly in a combobox.datasource line.
The first problem is that I can't get the code correct to setup the combobox control where it allows me to use .items.add("") and in extension .datasource
Error Message = "Object reference not set to an instance of an object"
dstcopt is the dataset from a oledbDataAdapter .fill(dstcopt,"table") line (which returns correct values)
tc_opt is a tab name on a tab control where the comboboxes are
For Each dstable In dstcopt.Tables
For Each dscolumn In dstable.Columns
Dim colName As String = dscolumn.ToString
MsgBox(colName) 'This retuns "aantigen"
Dim cb As ComboBox = Me.tc_opt.Controls("cb_" & colName)
cb.Items.Add(colName)
'cb_aantigen.DataSource = dstcopt.Tables(dstable.ToString)
'cb_aantigen.DisplayMember = "aantigen"
'cb_atarget.DataSource = dstcopt.Tables(dstable.ToString)
'cb_atarget.DisplayMember = "atarget"
Next
Next
The second problem comes when I do it manually (which works) using the exact combobox names cb_aantigen and cb_atarget as seen in the comments.
The problem is that once the form is loaded and the cb's are filled with the correct values, I can't change the value in any single cb individually, when I change one value it changes them all (there is 15 comboboxes in total) I know this is down to using a dataset, but I don't know away to 'unlink them from each other or the dataset'
Not sure if I need to split this into 2 questions, but help on either problem would be appreciated.
EDIT:
After looking at only this section of code for a day. This is what I have come up with to tackle both the problems at once.
The combobox control not working was down to using a tab tc_opt instead of a groupbox gp_anti
The issue with splitting the dataset up into individual comboboxes, I've worked around by taking the value of each cell in the database and adding it separately, probably a better way to do it though
For Each dstable As DataTable In dstcopt.Tables
For Each dscolumn As DataColumn In dstable.Columns
Dim colName As String = dscolumn.ToString
Dim cb(2) As ComboBox
cb(0) = CType(Me.gp_anti.Controls("cb_" & colName), ComboBox)
cb(1) = CType(Me.gp_rec.Controls("cb_" & colName), ComboBox)
cb(2) = CType(Me.gp_nat.Controls("cb_" & colName), ComboBox)
For icb = 0 To cb.Count - 1
If Not (IsNothing(cb(icb))) Then
For irow = 0 To dstable.Rows.Count - 1
If dstable.Rows(irow)(colName).ToString <> Nothing Then
Dim icbitemdupe As Boolean = False
If cb(icb).Items.Contains(dstable.Rows(irow)(colName).ToString) Then
icbitemdupe = True
End If
If icbitemdupe = False Then
cb(icb).Items.Add(dstable.Rows(irow)(colName).ToString)
End If
End If
Next
End If
Next
Next
Next
I have a form with a datagridview containing entries for an invoice. I have created a separate form that will contain the entries from the datagridview in labels. Unfortunately, I am having trouble finding out how to generate a table of labels with each label holding the value of the corresponding entry in the datagridview. I am wondering if it is possible to do this with a for next loop based on the number of rows in the datagridview. Thanks in advance for any guidance in this!
Dim lbl As New Label
With lbl
.Text = txtCaption ' value you want it to display from dgv.dr
.Top =
.Left =
.Name =
.Size =
End With
I dont know what you mean by a table of labels, so lets say you want to add them to a panel there just for them:
pnlLabels.Controls.Add(lbl)
Make that a Sub and call it from the loop processing the rows in the datagridview, passing the relevant value for its caption. Something like this:
CreateLabel(ndx as Integer, txtCaption as String)
You will need an index or counter of how many made so that some properties like .Top can be offset accordingly.
EDIT
I have no idea what your dgv or data etc looks like, but your loop would be SOMETHING like this:
pnlLabels.Controls.Clear ' might want to remove any old ones
Dim Caption as String = ""
Dim ndx As Integer = 0
For Each dr As DataGridViewRow in dgv.rows
Caption = dr.Cells(X) ' or where the data is
CreateLabel(ndx, Caption)
ndx += 1
Next
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.
I have a list box on a form and it works fine for what I want to do.
I am wanting to edit items on the form, this means populating the listbox and then selecting the relevant items.
My listbox contains a list of item sizes, i want to select the sizes which belong to the item being edited.
PLease can someone give me some pointers.
I tried me.lstItemSizes.SetSelected(i,true) but this only works for a single item.
Any help wil be much appreciated.
My Code:
Private Sub SelectItemSizes(ByVal itemID As Integer)
Dim itemSizes As IList(Of ItemSize) = _sizeLogic.GetItemSizes(itemID)
Me.lstItemSizes.SelectionMode = SelectionMode.MultiExtended
If (itemSizes.Count > 0) Then
For i As Integer = 0 To Me.lstItemSizes.Items.Count - 1
For x As Integer = 0 To itemSizes.Count - 1
If (CType(Me.lstItemSizes.Items(i), PosSize).SizeID = itemSizes(x).SizeID) Then
Me.lstItemSizes.SetSelected(i, True)
Else
Me.lstItemSizes.SetSelected(i, False)
End If
Next
Next
End If
End Sub
Did you set the selectionmode to multi?
You need to specify that in order to allow multiple selections.
Then you can do:
Dim i as Integer=0
For i=0 To Me.listBox.SelectedItems.Count -1
'display the listbox value
next i
Here is a screen shot:
After you set the property on the listbox then call setselected based on the values you want selected.
me.lstItemSizes.SetSelected(3,true)
me.lstItemSizes.SetSelected(4,true)
me.lstItemSizes.SetSelected(9,true)
Here you can add 20 numbers and only select the even.
Dim i As Integer
'load the list with 20 numbers
For i = 0 To 20
Me.ListBox1.Items.Add(i)
Next
'now use setselected
'assume only even are selected
For i = 0 To 20
If i Mod 2 = 0 Then
Me.ListBox1.SetSelected(i, True)
End If
Next
3rd edit
Look at the way you are looping, lets assume I create a list of integers, my vb.net is rusty I mainly develop in C#. But assume you did this:
Dim l As New List(Of Integer)
l.Add(2)
l.Add(6)
l.Add(20)
You only have three items in your list, so first loop based on the items on your list, then within the items in your listbox, you have it vice versa. Look at this:
Dim i As Integer
Dim l As New List(Of Integer)
l.Add(2)
l.Add(6)
l.Add(20)
'load the list with 20 numbers
For i = 0 To 20
Me.ListBox1.Items.Add(i)
Next
Dim lCount As Integer = 0
For lCount = 0 To l.Count - 1
For i = 0 To 20
If i = l.Item(lCount) Then
Me.ListBox1.SetSelected(i, True)
Exit For
End If
Next
Next
In the code my l is a list of just 3 items: 2, 6, and 20.
I add these items to l which is just a list object.
So now I have to loop using these 3 numbers and compare with my listbox. You have it the opposite you are looping on your listbox and then taking into account the list object.
Notice in my for loop that once the item in my list is found I no longer need to loop so I exit for. This ensures I dont overdue the amount of looping required. Once the item is found get out and go back to the count of your list object count.
After running my code here is the result
You have to change the ListBox.SelectionMode property in order to enable multiple-selection.
The possible values are given by the SelectionMode enum, as follows:
None: No items can be selected
One: Only one item can be selected
MultiSimple: Multiple items can be selected
MultiExtended: Multiple items can be selected, and the user can use the Shift, Ctrl, and arrow keys to make selections
So, you simply need to add the following line to the code you already have:
' Change the selection mode (you could also use MultiExtended here)
lstItemSizes.SelectionMode = SelectionMode.MultiSimple;
' Select any items of your choice
lstItemSizes.SetSelected(1, True)
lstItemSizes.SetSelected(3, True)
lstItemSizes.SetSelected(8, True)
Alternatively, you can set the SelectionMode property at design time, instead of doing it with code.
According to MSDN, SetSelected() can be used to select multiple items. Simply repeat the call for each item that needs to be selected. This is the example they use:
' Select three items from the ListBox.
listBox1.SetSelected(1, True)
listBox1.SetSelected(3, True)
listBox1.SetSelected(5, True)
For reference, this is the MSDN article.
Because my code had the following loops:
For i As Integer = 0 To Me.lstItemSizes.Items.Count - 1
For x As Integer = 0 To itemSizes.Count - 1
If (CType(Me.lstItemSizes.Items(i), PosSize).SizeID = itemSizes(x).SizeID) Then
Me.lstItemSizes.SetSelected(i, True)
Else
Me.lstItemSizes.SetSelected(i, False)
End If
Next
Next
The first loop loops through the available sizes and the second loop is used to compare the item sizes.
Having the following code:
Else
Me.lstItemSizes.SetSelected(i, False)
End If
Meant that even if item i became selected, it could also be deselected.
SOLUTION:
Remove Me.lstItemSizes.SetSelected(i, False) OR Include Exit For