I have custom ComboBox, where DropDownStyle = ComboBoxStyle.DropDown;.DropDown style is set because I want to set the Text property of the ComboBox to something outside the list of values. Everything works good, except that ComboBox is highlighting the text when it's left and when I click on the combobox editing is avaible. How can I cope with this?
To illustrate:
First Picture is where everything looks good, second is the highlight situation, third editing is on.
Try un-selecting the text after the DropDown closes:
void comboBox1_DropDownClosed(object sender, EventArgs e) {
this.BeginInvoke(new Action(() => { comboBox1.Select(0, 0); }));
}
If you are referring to disabling the highlighting and editing, then you might want to consider setting the DropdownStyle property to DropdownList.
yourComboBox.DropDownStyle = ComboBoxStyle.DropDownList;
Tricky problem to solve. It seems to be from the Resize event. There are a lot of solutions that do something similar to this, but none that I've seen worked for me until I tried this. (This is a solution that does not require inheritance from ComboBox; inheriting is probably a much more straight forward solution, but requires you to always use your inherited class and never the actual ComboBox class.)
comboBox.Resize += (s, e) => {
if (!comboBox.IsHandleCreated)
return; // avoid possible exception
comboBox.BeginInvoke(new Action(() => comboBox.SelectionLength = 0));
};
Set the selection length to zero to get rid of the highlight, but when? Other examples do it in other places, but the problem seems to be specifically caused by Resize, so doing it after Resize fixes it consistently, at least for me. (Can still see it flicker when you resize the window though, but it always ends up ok.)
BeginInvoke ensures that it happens sufficiently after Resize to work, and the check for IsHandleCreated prevents it from being called before the handle is created, in which case BeginInvoke would throw an exception.
This slightly more complex version includes some checks to prevent a focused control from losing highlight, since it actually should have it. It also doesn't fire if the parent doesn't exist yet, or if the parent does not have an active control yet, both signs that things are too early.
comboBox.Resize += (s, e) => {
if (!comboBox.IsHandleCreated)
return;
comboBox.BeginInvoke(new Action(() => {
var parent = comboBox.FindForm();
if (parent == null)
return;
if (parent.ActiveControl == null)
return;
if (parent.ActiveControl == comboBox)
return;
comboBox.SelectionLength = 0;
}));
};
I tried to make a version that would 'preserve' the selection length rather than always set it to zero, but I couldn't get it to synchronize properly. Many Resize events can fire before the BeginInvoke delegates start to fire, so the preserved value will always be overwritten by the broken one. I tried saving them all in a Queue or Stack, but in both cases, I was unable to reverse the ordering (not really sure why, since that makes no sense).
To solve the same I have tried almost EVERYTHING:
setting the DropdownStyle property to DropdownList
this.BeginInvoke(new Action(() => { comboBox1.Select(0, 0); }));
combobox1.SelectionLength = 0;
changing comboBox.TabIndex
Not tried SendKeys.Send("{ESC}"); because it is not a reliable solution
Nothing helped.
The only stable and working solution was to move a focus on another Label control:
label.Focus();
You could also hide that label.
I know this post is old but recently I have the same problem with combobox.
Situation : I have an editable combobox which propose complete words when user write some letters.
But when I want to type a letter, combobox auto highlight the text and the next letter auto replace the previous.
Solution : I use a textbox to avoid any highlight like that:
<ComboBox IsTextSearchEnabled="False" IsEditable="True" x:Name="CMB_ClientName"/>
<TextBox Text="{Binding ElementName=CMB_ClientName, Path=Text}" TextChanged="ComboBoxChange" x:Name="TXT_ClientName"/>
And I generate the textbox TextChanged event :
private void ComboBoxChange(object sender, TextChangedEventArgs e)
{
//Clear ComboBox items
CMB_ClientName.Items.Clear();
//Auto Open DropDownList
CMB_ClientName.IsDropDownOpen = true;
//Get data from database (use entity framework 6.x)
dbEntity.Client.Load();
//Attribute Data to variable
var clients = dbEntity.Client.Local;
foreach (Client client in clients)
{
//If data begin with the texbox text, the data is add to the combobox items list.
if (client.Nom.ToLower().StartsWith(TXT_NomClient.Text.ToLower()))
{
CMB_ClientName.Items.Add(client.Nom);
}
}
}
I know this solution isn't realy beautifull, but it is for me the easiest solution to avoid highlight text and all the solutions in this post don't work for me.
I hope this solution will be helpfull, thanks for reading.
Math.
Ps: My apologies, my English is not very good. I hope you will understand me correctly.
Nothing worked for me ( I want the form to load with no highlighting in any combobox) until I set the combobox property TabStop to false. This meant that one of my buttons took the tab highlight which I didn't like so I set them all to false for start up and adjusted them programatically as needed.
I know this is an old thread, but my solution is similar to that of the others, but relies on the Form.ResizeEnd event. In its event handler, I iterate through the ComboBoxes and set ComboBox.SelectionLength to 0.
private void Form_ResizeEnd(object sender, EventArgs e)
{
foreach(ComboBox comboBox in parentControl.Controls.OfType<ComboBox>
{
comboBox.SelectionLength = 0;
}
}
This is what worked for me:
Set DrawMode to OwnerDrawFixed
Set cbxSubsystems.DrawItem event to the function below
private void cbxSubsystems_DrawItem(object sender, DrawItemEventArgs e)
{
Color BgClr;
Color TxClr;
if( (e.State & DrawItemState.ComboBoxEdit) == DrawItemState.ComboBoxEdit )
{
// Do not highlight main display
BgClr = cbxSubsystems.BackColor;
TxClr = cbxSubsystems.ForeColor;
}
else
{
BgClr = e.BackColor;
TxClr = e.ForeColor;
}
e.Graphics.FillRectangle(new SolidBrush(BgClr), e.Bounds);
TextRenderer.DrawText(e.Graphics, cbxSubsystems.Items[e.Index].ToString(), e.Font, e.Bounds,
TxClr, BgClr, TextFormatFlags.Left | TextFormatFlags.VerticalCenter );
}
Related
I have a winform in vs2008 that contains a DataGridView. The datagrid contains a list with several columns. These are fixed width, exept one that I have set up to take whatever space is left and fill the width of the view. The winform is resizeable in all directions.
The issue I am trying to solve is that when I increase the vertical size of the window the scrollbar disappears and the columns snap to the right to fill the extra space. What I would like to happen is that the vertical scrollBar never disappears. Setting ScrollBars to vertical in the properties of the DataGridView does not do this.
Is this at all possible to achieve? And, if so, how do I get the vertical scrollbar to always be visible?
Try subclassing the DataGridView and handling the VerticalScrollBar's VisibleChanged event. You should be able to set the Visible property to True in there, overriding the default behaviour.
Something like this, I think...
public class SubclassedDataGridView : DataGridView
{
public SubclassedDataGridView (): base()
{
VerticalScrollBar.VisibleChanged += new EventHandler(VerticalScrollBar_VisibleChanged);
}
void VerticalScrollBar_VisibleChanged(object sender, EventArgs e)
{
VerticalScrollBar.Visible = true;
}
}
In my case, (re)sorting the grid helped. Try sth like this:
if (gridName.SortedColumn == null)
gridName.Sort(gridNameColumns[columnName],ListSortDirection.Ascending);
else
{
ListSortDirection dir;
if (gridName.SortOrder == SortOrder.Descending)
dir = ListSortDirection.Descending;
else dir = ListSortDirection.Ascending;
gridName.Sort(gridName.SortedColumn, dir);
}
One of the possibility is to trigger the event of when the scrollbar is disapearing so you can prevent the event and stop it.
I am using the TreeView from the WinrtXamlToolkit. The default behavior of this control is to expand the nested items on double click of the header. The code responsible for this is here (TreeViewItem.cs line 1205).
private void OnHeaderMouseLeftButtonDown(object sender, PointerRoutedEventArgs e)
{
if (Interaction.AllowMouseLeftButtonDown(e))
{
// If the event hasn't already been handled and this item is
// focusable, then focus (and possibly expand if it was double
// clicked)
if (!e.Handled && IsEnabled)
{
if (Focus(FocusState.Programmatic))
{
e.Handled = true;
}
// Expand the item when double clicked
if (Interaction.ClickCount % 2 == 0)
{
bool opened = !IsExpanded;
UserInitiatedExpansion |= opened;
IsExpanded = opened;
e.Handled = true;
}
}
Interaction.OnMouseLeftButtonDownBase();
OnPointerPressed(e);
}
}
Is there a way to change this behavior to expand the items on single click or tap without actually copying the control and all it's related classes to my project?
It seems like an overkill to do this just to change a few lines of code.
I tried to do drag'n'drop stuff with that TreeView and was in a similar situation. My first move was to actually copy all the TreeView and its related classes and man there are a lot. There's a lot of internal stuff happening and I pretty much gave up interfering with it after a bunch of other stuff stopped working.
So my solution was to just have a specific control inside the ItemTemplate that handled dragging for me. For you this would be a Button whose Click you handle. In the eventhandler you will navigate up the visual tree to your TreeViewItem and change the IsExpanded.
I'm trying to create a simple listbox with ObjectListView (WinForm, C#). The goal is to have a single value (a double) and a check box.
I want to be able to edit the double value by Single Click, so here are the relevant lines of code from my MyWindow.Designer.cs file (i've left out the default values for efficiency):
this.olvDepths = new BrightIdeasSoftware.ObjectListView();
this.olvColumn1 = ((BrightIdeasSoftware.OLVColumn)(new BrightIdeasSoftware.OLVColumn()));
...
this.olvDepths.CellEditActivation = BrightIdeasSoftware.ObjectListView.CellEditActivateMode.SingleClick;
this.olvDepths.CheckBoxes = true;
this.olvDepths.CheckedAspectName = "IsDefault";
this.olvDepths.FullRowSelect = true;
//
// olvColumn1
//
this.olvColumn1.AspectName = "Depth";
this.olvColumn1.Text = "";
this.olvColumn1.IsEditable = true;
I then create a list of my class (ShieldingEntry) and use the olvDepths.SetObjects() with the list. My ShieldingEntry class looks like this:
public class ShieldingEntry
{
public double Depth { get; set; }
public bool IsDefault { get; set; }
}
However, when I click the field, it doesn't go into edit mode. I've also tried the DoubleClick, SingleClickAlways, and F2Only modes and they don't work either.
The Checkbox works fine.
************** I have additional information *********************
I've pulled and build the ObjectListView source, so I could step through it.
I put a breakpoint in the OLV StartCellEdit method and it gets called and appears to setup and select the control appropriately. It just never appears...
As I noted in the comments on the answer below, I've got this control on a tabbed dialog, and if I switch to another tab, then back, the control works fine.
What am I missing?
I've used ObjectListView before, and here is what I had to do:
Handle the CellEditStarting event. This event is raised when the cell goes into edit mode. Since OLV doesn't really have built-in editors, you have to make your own. Then handle the CellEditFinishing event to validate the data before putting it back into your model.
So first, handling the CellEditStarting event:
private void objlv_CellEditStarting(object sender, CellEditEventArgs e)
{
//e.Column.AspectName gives the model column name of the editing column
if (e.Column.AspectName == "DoubleValue")
{
NumericUpDown nud = new NumericUpDown();
nud.MinValue = 0.0;
nud.MaxValue = 1000.0;
nud.Value = (double)e.Value;
e.Control = nud;
}
}
This creates your editing control. If you want to make sure the size is right, you can set the size of the control (in this case a NumericUpDown) to the cell bounds using e.CellBounds from the event object.
This will show the editor when you click in the cell. Then you can handle the editor finished event to validate the data:
private void objlv_CellEditFinishing(object sender, CellEditEventArgs e)
{
if (e.Column.AspectName == "DoubleValue")
{
//Here you can verify data, if the data is wrong, call
if ((double)e.NewValue > 10000.0)
e.Cancel = true;
}
}
I don't think handling it is required, but its good practice to validate data from the user.
The editing control in the CellEditStarting event can be any control, even a user defined one. I've used a lot of user defined controls (like textboxes with browse buttons) in the cell editor.
[Edit]
I uploaded an example here dropbox link that seems to work. Might not be in the exact view as needed, but seems to do the job.
For anyone else with this problem. I had it specifically when trying to edit a 'null' value in a decimal? on the OLV on a tab page. Solution for me was to set UseCustomSelectionColors to 'False'. I didn't look elsewhere to see if it was reported as a bug. Seems like a bug.
I asked this question previously and did not get an answer but now I have more detail.
Basically I want to programatically display the column sort icon in a wpf datagrid column.
I have the following code to do this:
private void dtgMain_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
dtgMain.Columns[0].SortDirection = ListSortDirection.Ascending;
}
This seems to set the sort order of the column but when the grid is drawn the icon does not show.
When I add a message box into the method it works fine. My question is twofold. Why would the message box cause the method to work? And how can I get it to work without the use of a messagebox?
This is the method working with the messagebox in it:
private void dtgMain_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
MessageBox.Show("Here");
dtgMain.Columns[0].SortDirection = ListSortDirection.Ascending;
}
edit
Here is the method that is setting the datacontext of the datagrid
public void processLoad(string response)
{
XmlDataProvider provider = new XmlDataProvider();
if (provider != null)
{
System.Xml.XmlDocument doc = new System.Xml.XmlDocument();
doc.LoadXml(response);
provider.Document = doc;
provider.XPath = "/moo/response/data/load/panel";
dtgMain.DataContext = provider;
}
}
Please let me know if you need anymore information.
OK, I suspect what is happening is that the data layout changes caused by the DataContext update are being completed after your call to set the direction arrow, and it is therefore being erased after you set it. Interestingly, in my case it failed to work even when I put the messagebox in, perhaps because that was hanging up the UI thread while it displayed.
Could you try replacing the line that sets the sort direction with a similar call put on the dispatcher queue:
dtgMain.Dispatcher.BeginInvoke(new Action(() =>
{
dtgMain.Columns[0].SortDirection = ListSortDirection.Ascending;
}), DispatcherPriority.ApplicationIdle);
and see if that works?
I have a treeview with nodes like this: "Foo (1234)", and want to allow the user to rename the nodes, but only the Foo part, without (1234). I first tried to change the node text in BeforeLabelEdit like this:
private void treeView1_BeforeLabelEdit(object sender, NodeLabelEditEventArgs e)
{
e.Node.Text = "Foo";
}
But when I click the node to edit it, "Foo (1234)" appears in the textbox.
Okay, then let's try something else.
I set treeView1.LabelEdit to false, and then do the following:
private void treeView1_MouseClick(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
if (treeView1.SelectedNode == treeView1.GetNodeAt(e.Location))
{
treeView1.SelectedNode.Text = "Foo";
treeView1.LabelEdit = true;
treeView1.SelectedNode.BeginEdit();
}
}
}
And then in AfterLabelEdit, I set LabelEdit back to false.
And guess what? This doesn't work either. It changes the node text to "Foo" but the edit textbox does not appear.
Any ideas?
Thanks
Finally I have found a solution to this on CodeProject. Among the comments at the bottom, you will also find a portable solution.
Heh - I struck that one a few years back. I even left a suggestion on Connect (vote for it!) to allow the label to be changed in BeforeLabelEdit.
One option (in WinForms - it's a different story in WPF) is to use custom painting for your TreeNodes so that the actual label is still "Foo" and you custom draw the " (1234)" after it. It's a bit of a pain to get right though.