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How to activate combobox on first click (Datagridview)

In winforms, you need to click the combobox twice to properly activate it - the first time to focus it, the second time to actually get the dropdown list.
How do I change this behavior so that it activates on the very first click?
This is for DATAGRIDVIEW combobox.

I realize this is an old question, but I figured I would give my solution to anyone out there that may need to be able to do this.
While I couldn't find any answers to do exactly this... I did find an answer to a different question that helped me.
This is my solution:
private void datagridview_CellEnter(object sender, DataGridViewCellEventArgs e)
{
bool validClick = (e.RowIndex != -1 && e.ColumnIndex != -1); //Make sure the clicked row/column is valid.
var datagridview = sender as DataGridView;
// Check to make sure the cell clicked is the cell containing the combobox
if(datagridview.Columns[e.ColumnIndex] is DataGridViewComboBoxColumn && validClick)
{
datagridview.BeginEdit(true);
((ComboBox)datagridview.EditingControl).DroppedDown = true;
}
}
private void datagridview_CurrentCellDirtyStateChanged(object sender, EventArgs e)
{
datagridview.CommitEdit(DataGridViewDataErrorContexts.Commit);
}
The above code must be tied into the CellEnter event of the datagridview.
I hope this helps!
edit: Added a column index check to prevent crashing when the entire row is selected.
Thanks, Up All Night for the above edit
edit2: Code is now to be tied to the CellEnter rather than the CellClick event.
Thanks, HaraldDutch for the above edit
edit3: Any changes will committed immediately, this will save you from clicking in another cell in order to update the current combobox cell.

Set the following on your DataGridView:
EditMode = EditOnEnter
This is probably the easiest solution and has been the workaround for many users here on SO when this question gets asked.
EDIT :
Per here do the following:
Set the Editmode:
EditMode = EditOnKeystrokeOrF2
Modify the EditingControlShowing event on the datagridview:
private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
ComboBox ctl = e.Control as ComboBox;
ctl.Enter -= new EventHandler(ctl_Enter);
ctl.Enter += new EventHandler(ctl_Enter);
}
void ctl_Enter(object sender, EventArgs e)
{
(sender as ComboBox).DroppedDown = true;
}
This will get you your desired results. Let me know if that doesn't do it.

I changed only the EditMode property of the datagridview to EditOnEnter and it's working perfectly.
EditMode = EditOnEnter

If you set the entire grid to EditOnEnter, you can get some pretty funky activity when you are on a text column. Here's my solution, which should be self explanatory. If you did not know the column names, you could just check the cell type on mousemove.
Private Sub GridView_CellMouseMove(sender As Object, e As System.Windows.Forms.DataGridViewCellMouseEventArgs) Handles GridView.CellMouseMove
Select Case GridView.Columns(e.ColumnIndex).Name
Case "Ad_Edit", "Size_Caption", "Demo_Code"
GridView.EditMode = DataGridViewEditMode.EditOnEnter
Case Else
GridView.EditMode = DataGridViewEditMode.EditOnKeystrokeOrF2
End Select
End Sub

Set the DropDownStyle property of your combo box to DropDownList...

Perhaps old.. But make sure to set ReadOnly property to false, else the cell wont enter editmode and therefore the EditingControl returns null and casting DroppedDown = true will cast a NullReferencException.

How to add buttons to datagridview cells not entire column

How do you add a button to cells in a row and not the entire column in a datagridview?

I think Adrian's answer was close. Try something like this.
if ((string)table.Rows[0].Cells[0].Value == "I should be a button") {
// you can add formatting or values to the button before assigning it here
table.Rows[0].cells[0] = new DataGridViewButtonCell();
}

I think the best answer if found here:
Hide gridview button. All you need to do is to add a DataGridViewButtonCell where you want buttons, and DataGridViewTextBoxCell where you do not. The column has to be DataGridViewButton type.

See this similar post in SO, probably helps
adding control to gridview
In case Win Form, Check this MSDN post
Column Types in the Windows Forms DataGridView Control
OR this code project post ... though it gives example of adding a image button
DataGridView Image Button Cell
#tmax In that case you can probably put your button creation code in GridView_RowCreated event like below
void GridView_RowCreated(Object sender, GridViewRowEventArgs e)
{
if(e.Row.RowType == DataControlRowType.Header)
{
//Button creation code here
}
}

private void dataGridView1_RowsAdded(object sender, DataGridViewRowsAddedEventArgs e)
{
Button btn = new Button();
//btn attributes
dataGridView1.Rows[0].Cells[3].Value = new Button();
}
try something like this.

What I endded up doing was stacking a DataGridView on top of another one. I turned off the border, gridlines, and scrollbars. Then create dynamic button columns to match the main datagridview with only one row of buttons. Then I used the ColumnWidthChanged event handler to resize both the DataGridViews together. Anyway's this was my workaround for now.

DataGridViewButtonColumn dataGridViewButtonColumn = new DataGridViewButtonColumn();
dataGridViewButtonColumn.Name = "Select";
dataGridViewButtonColumn.HeaderText = "Select";
dataGridViewButtonColumn.ReadOnly = false;
dataGridView1.Columns.Add(dataGridViewButtonColumn);

After assigning data source to gridviewCTRL. you can add new column with button with below code.
DataGridViewButtonColumn startbtn = new DataGridViewButtonColumn();
startbtn.Name = "Action";
startbtn.Text = "Start";
startbtn.UseColumnTextForButtonValue=true;
int columnIndex = 6;
gridviewCTRL.Columns.Insert(columnIndex, startbtn);
This will add the button to each and every row at define column index.
if you want to render condition the AccessibleObject, then you can do something similar to below.
foreach (DataGridViewRow rowdata in gridviewCTRL.Rows)
{
// this is just an example in my case i am checking a previous column value
if (rowdata.Cells[5].Value=="XYZ")
{
rowdata.Cells[6] = new DataGridViewTextBoxCell();
}
}
This way you can dynamically render/ showing the control in the GridView in Winforms c#.
The above code simple update the cell with new cell. We can't remove button from the cell nor remove whole, so instead we can initial a new cell that will override the button visibility.

I am not sure if this will help but you can also consider using TableLayoutPanel.
Refer: Winforms TableLayoutPanel adding rows programmatically

How can I prevent cells in the "new" datagridview row from being selected if there are multiple datagridview rows selected?

Don't ask why, but I need a way to prevent the user from entering a cell in the 'new' datagridview row WHILE they've got multiple rows selected.
Currently, the cell in the first column of the row that the mouse is hovering over during the click and drag is being selected. If you click on the cell, then the rows aren't selected anymore, so you can't use any cell click events or anything.
Any suggestions are welcome.
P.S. don't try editing the currentcell from the selectionchanged event, already tried that!
Thanks,
Isaac

I have an idea that the DataGridView control has a RowState property. When your row is selected, check the state. I'm not sure what the states are (if I'm even in the ballpark) ... anyway, you may be able to check that route.
I'm looking for more info ...
Okay ... think I found a decent way to do this:
void DataGridView1_RowsAdded (object sender, DataGridViewRowsAddedEventArgs e)
{
currentNewRow = e.RowIndex;
}
void DataGridView1_CellMouseClick(Object sender, DataGridViewCellMouseEventArgs e)
{
if (e.RowIndex == currentNewRow)
{
// don't add to Selection
}
}

Use CellStateChanged event:
private void dataGridView_CellStateChanged(object sender, DataGridViewCellStateChangedEventArgs e) {
if (e.Cell.OwningRow.IsNewRow && dataGridView.SelectedRows.Count > 1)
e.Cell.Selected = false;
}

Visible Checkbox only on Gridview's last row?

Is it possible to have a Checkbox that only shows up when Editing the last row of a GridView?
I have tried something like this in the EditItemTemplate:
<asp:CheckBox ID="chkNextDay" runat="server"
ToolTip="Is it a next-day departure?"
Enabled="true"
Checked='<%# DateTime.Parse(Eval("OutHour","{0:d}")).Date >
DateTime.Parse(Eval("InHour","{0:d}")).Date %>'/>
Then on code-behind I tried hiding it for rows other than the last one like this:
protected void grvOutHour_RowEditing(object sender, GridViewEditEventArgs e)
{
GridView grvOutHour = (GridView)this.grvReport.Rows[grvReport.EditIndex].FindControl("grvOutHour");
TextBox txtBox = (TextBox)grvOutHour.Rows[e.NewEditIndex].FindControl("txtEditOutHour");
CheckBox nextDay = (CheckBox)grvOutHour.Rows[e.NewEditIndex].FindControl("chkNextDay");
if (grvOutHour.Rows.Count-1 != e.NewEditIndex)
nextDay.Visible = false;
}
This ALMOST worked, but the checkbox kept showing for all fields, I think because the RowDataBound is called AFTER RowEditing again so it renders the whole thing again :(
Any suggestions?
Thanks,
EtonB.

Use RowDataBound instead...
protected void grvOutHour_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowState == DataControlRowState.Edit)
{
GridView grid = (GridView)sender;
CheckBox nextDay = (CheckBox)e.Row.FindControl("chkNextDay");
nextDay.Visible = (e.Row.RowIndex == (grid.Rows.Count - 1));
}
}

You will need to handle hiding the checkbox in the RowDataBound event.
You'll need to determine what the last row is, and set the checkboxes visible property to true when that condition is true, obviously.

I guess it's more of a hack than an elegant solution, but I would probably just hide the other checkboxes via JavaScript if the condition is true.

C# listview clickable column and row

What I have going on is a listview inside of my windows form.
How can I make so that only when you double click a row it pulls data for row X and column 3.
meaning I have a listview of...
A|B|C|D
1|2|3|4
#|#|$|%
Bc|Dv|D#|dg
so if i double clicked row thats begins with # it will read in column 3 ($).
I aleady have FullRowSelect = True
I figured this out thanks everyone!
string hyperurl = listView1.FocusedItem.SubItems[2].Text;

Use this code for your ListView's DoubleClick event:
private void listView1_DoubleClick(object sender, EventArgs e)
{
if (listView1.SelectedItems.Count > 0)
{
ListViewItem item = listView1.SelectedItems[0];
MessageBox.Show(item.SubItems[2].ToString());
}
}

Maybe this can help:
http://msdn.microsoft.com/en-us/library/system.windows.forms.listview.selectedindexchanged.aspx