how to assign a cell value to a grid view control cell from a string variable(local variable) using VB.net
After the gridview is populated, I would like to insert some data into one of the cells in a row in edit mode.
Create a label in the cell that is being bound, but leave it unbound. Then in the RowDataBound event you can find the label in the cell and populate it with the value you want.
private myString as String = "Some String"
... blah blah code ...
Protected Sub myGridview_RowDataBound(ByVal sender as Object, ByVal e as GridviewRowEventArgs) Handles myGridview.RowDataBound
If e.Row.RowType = RowTypes.DataRow Then
Dim index as Integer = 3 ' Make this the index of your cell
Dim lbl as Label = CType(e.Row.Cells(index).FindControl("myLabelName"), Label)
lbl.Text = myString
End If
End Sub
You can also do this with a literal, panel, etc. The key is to make sure you get the index right and make sure that you use the name provided in the ItemTemplate when using the FindControl method.
myGridView.Rows(x).Cells(y).Text = someValue
you might get an exception though, if this is a bound control.
Related
I have a DatagridView whose DataSource is a DataTable.
When I change a cell's value at runtime, it appears to be changing well.
However, if I try to assign a value from the DataGridView to a variable by clicking on a row in the DatagridView, the variable gets the original (DataTable) value, not the cell's value.
copy = DataGridView2.Item(7, i).Value
The ReadOnly property of the cells column is false.
Any suggestion?
I was able to solve the problem with this method:
Private Sub DataGridView2_CellEndEdit(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridView2.CellEndEdit
Dim i As Integer
i = DataGridView2.CurrentRow.Index
DataGridView2.DataSource.Rows(i)("copy") = DataGridView2.CurrentCell.Value
End Sub
This way, the variable will take on the correct value after I overwrite the value of the cell in the DatagridView.
I am here to find out is it possible to complete my idea to save me time writing long code.
I have 1 main combobox with various items and some other comboboxed. Each combobox of them is called "Combo" + the item from the main combobox.
and I wonder can I, when I click on an item to hide the last used combobox and to show the combobox linked to this item?
1. hide last used combobox
2. show the combobox responding to the selected item from the main combox
Public Sub ComboBox2_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox2.SelectedIndexChanged
Dim SelectedAction As String = "Combo" + ComboBox2.Text
lastcombobox.visible = false
' now to assign to the new combobox
lastcombobox = (SelectedAction as name of combobox) combobox
Lastcombobox.visible = true
End Sub
Strings are not controls. Strings are the data type of Control.Name; that is the Name property of the control object. You cannot cast a string to a control but all is not lost. Create your other Combo Boxes at design time and stack them on top of each other. Notice the Static keyword before lastComboBox. This persists the value between calls to the method. You could accomplish the same thing by making this variable a class level variable. The first time the method is called their will be nothing in lastComboBox therefore the check for IsNothhing. Control.Find returns an array so we must refer to ctl(0) - the first element of the array, since we know it will return only one.
Private Sub Combo2_SelectedIndexChanged(sender As Object, e As EventArgs) Handles Combo2.SelectedIndexChanged
Dim SelectedAction As String = "Combo" & Combo2.Text
Static lastComboBox As ComboBox
If Not IsNothing(lastComboBox) Then
lastComboBox.Visible = False
End If
Dim ctl() As Control = Controls.Find(SelectedAction, True)
lastComboBox = CType(ctl(0), ComboBox)
lastComboBox.BringToFront()
lastComboBox.Visible = True
End Sub
I have a user form with a combobox, with 5 unbound data items. The value of each item is of the following format: "## Explanation", a 2-digit numeric code and an explanation of the code. After the user selects an item, I would like to have the 2-digit numeric code displayed only. I have tried the following
Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
ComboBox1.Text = Mid(ComboBox1.Text, 1, 2)
End Sub
However after selecting an item, the assignment doesn't seem to be working properly because ComboBox1.Text remains unchanged. Any ideas? Thanks in advance
To me, it sounds that you are not really using combo box to full potential. Looks like you want to have items with multiple pieces of info, which you're trying to combine. But here what you can do instead
Private Class ComboItem
Public Property Code As Integer
Public Property Description As String
Public ReadOnly Property Display As String
Get
Return Code & " " & Description
End Get
End Property
End Class
Dim lst As New List(Of ComboItem)()
lst.Add(New ComboItem()....) ' add your items
cboList.DataSource = lst
cboList.DisplayMember = "Display"
cboList.ValueMember = "Code"
Here where the best part starts - once user selects an item, by typing or clicking, you can do this
Dim item As ComboItem = DirectCast(cboList.SelectedItem, ComboItem)
txtCode.Text = item.Code
txtDescription.Text = item.Description
I feel, this is what you really need.
You would have to change the value in the combobox's Items collection. If you just change the Text property this is what happens:
Setting the Text property to null or an empty string ("") sets the SelectedIndex to -1. Setting the Text property to a value that is in the Items collection sets the SelectedIndex to the index of that item. Setting the Text property to a value that is not in the collection leaves the SelectedIndex unchanged.
I have a datagridview with two textbox columns and one combobox column. The combobox's DataSource is bound to enums for the values of the dropdown. The datagridview's DataSource is bound to a custom class with datatypes of string, string and enum.
The first two columns are pre-populated with values and in the third column the user must select a value from the dropdown. All this is working excellent so far except....
The combobox field should be a one-to-one kind of mapping, meaning no two comboboxes should have the same value. I am really not sure how to implement this kind of behavior. Should the chosen value be removed from the remaining dropdowns? should the chosen value remain in the dropdown and just give an error when two of the same are selected?
Any ideas and how to implement these ideas will be of great help.
Thanks
note the only acceptable value that can be used more than once is 'None'
I have an idea based off your intent to possibly remove the chosen value from the remaining dropdowns.
I have a class called Runner which has a similar setup to your example.
Public Class Runner
Public Property FirstName As String
Public Property LastName As String
Public Property Placement As Result
Public Sub New(fn As String, ln As String)
FirstName = fn
LastName = ln
Placement = Result.None
End Sub
End Class
I also have an enum called Result which will get populated into the ComboBoxCell:
Public Enum Result
None = 0
Bronze = 1
Silver = 2
Gold = 3
End Enum
When I create data objects and bind them to the DataGridView, I do so like this (note - Placements is a global List(Of Result) and Runners is a global List(Of Runner):
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Placements.Add(Result.None)
Placements.Add(Result.Bronze)
Placements.Add(Result.Silver)
Placements.Add(Result.Gold)
Runners.Add(New Runner("John", "Smith"))
Runners.Add(New Runner("Jane", "Doe"))
Runners.Add(New Runner("Bill", "Jones"))
Column1.DataPropertyName = "FirstName"
Column2.DataPropertyName = "LastName"
Column3.DataPropertyName = "Placement"
Column3.DataSource = Placements
DataGridView1.DataSource = Runners
End Sub
Now, whenever the value of a cell in the ComboBoxColumn changes, you remove the new value from the list that contains the enums:
Private Sub DataGridView1_CellValueChanged(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridView1.CellValueChanged
If (e.RowIndex > -1 And e.ColumnIndex = 2) Then
Dim currentvalue As Result = DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex).Value
If currentvalue <> Result.None Then
Placements.Remove(currentvalue)
End If
End If
End Sub
Be careful when changing drop down selections... as per this Discussion, you have to trick the DataGridView into committing values as soon as the ComboBox value changes. I used an answer from that discussion and did something like this:
Private Sub DataGridView1_CurrentCellDirtyStateChanged(sender As Object, e As EventArgs) Handles DataGridView1.CurrentCellDirtyStateChanged
Dim col As DataGridViewColumn = DataGridView1.Columns(DataGridView1.CurrentCell.ColumnIndex)
If col.Name = "Column3" Then
DataGridView1.CommitEdit(DataGridViewDataErrorContexts.Commit)
Dim selected As DataGridViewCell = DataGridView1.CurrentCell
DataGridView1.CurrentCell = Nothing //This line and the next one simply hide
DataGridView1.CurrentCell = selected //an odd display effect that occurs
//because we remove a value and change the
//selection at the same time
End If
End Sub
Finally, you want to handle the DataError event for the DataGridView and leave it blank so that you don't get Exceptions thrown at you when removing values from your list of enums.
This gets you about 90% of the way there. It will not re-add items to the list when you change a value. For example if I change from Gold to Silver, Gold should be added back to the list. You can probably figure out what events to handle to get the old value and the new one, and insert the old value back into the list at the correct index based on its enum value.
I decided to use the CellValidating event of the DataGridView to check whether or not the same value is selected more than once. If it is then a error message is displayed in the row header column.
The combobox in error will not lose focus until the error is resolved.
Private Sub DataGridView1_CellValidating(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellValidatingEventArgs) Handles DataGridView1.CellValidating
Dim headerText As String = DataGridView1.Columns(e.ColumnIndex).HeaderText
'Abort validation if cell is not in the Mapping column.
If Not headerText.Equals("Column Mapping") Then Return
'Clear error on current row.
DataGridView1.Rows(e.RowIndex).ErrorText = Nothing
e.Cancel = False
Dim newMappingValue As XmlElement = DirectCast([Enum].Parse(GetType(XmlElement), e.FormattedValue), XmlElement)
' Abort validation if cell value equal XmlElement.None
If newMappingValue.Equals(XmlElement.None) Then Return
For Each dgvRow As DataGridViewRow In DataGridView1.Rows
Dim currentMappingValue As XmlElement = dgvRow.Cells.Item(headerText).Value
If dgvRow.Index <> e.RowIndex Then
If currentMappingValue.Equals(newMappingValue) Then
DataGridView1.Rows(e.RowIndex).ErrorText = "Value already selected, please select a different value."
e.Cancel = True
End If
End If
Next
End Sub
How can I select a single cell from selected row in datagridView and after selecting that I want to put simple search functionality (like we have in our windows folders-typing any characters and search should work)?
I do not really understand your question. If you want to select one cell, you can use the celldoubleclick event for exemple. And the to get the selected cell, use e.rowindex and e.columnindex which will give you the row and the column where the cell is located.
You can try this as a possible solution.
Dim nwData as CustomersDataSet = CustomersDataSet.GetCustomers()
m_CustomersGrid.DataSource = m_CustomersBindingSource
m_CustomersBindingSource.DataSource = nwData.Customers
Then you can sort using the BindingSource.
CustomersBindingSource.Sort = "ContactName ASC"
And you can find using the BindingSource.
Dim index as integer = _
CustomersBindingSource.Find("CompanyName", CompanyNameTextBox.Text)
If index <-1 then 'it was found; move to that position
CustomersBindingSource.Position = index
End If
You could then populate:
CustomersBindingSource.Find("CompanyName", CompanyNameTextBox.Text)
with the keys pressed in the cell by capturing them by utilizing:
Private Sub DataGridView1_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles DataGridView1.KeyUp
Dim dgv As DataGridView = TryCast(sender, DataGridView)
If dgv IsNot Nothing Then
'You will need some logic here to determine how long to wait between keyups
'Perhaps a timer that ticks every500 milliseconds and reset on keyup.
e.KeyData
End If
End Sub
I found the original Biding Source Logic at : This Location