Develop Reference

C# ComboBox disable highlighting

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 );
}

Winforms Control Layout at Runtime

I've been working on developing a custom control which will be used in our CRM frontend. The control itself is nothing special, it simply wraps two labels, text edits, and a button into a single control. (The control is only acting as a wrapper, a bit long winded, but unfortunately our only option due to various restrictions)
I though it would be nice to give the control a Font and ForeColor property, that would change the Font and Color of the labels. Changing the font size means that the relative position of the text boxes be changed to keep everything in line. No problem.
I encapsulated the layout logic in an UpdateLayout method, which is called on the set accessor of the Font property and everything works beautifully at design time, however, at runtime, the Font of the labels is correct, but the layout of the text boxes and button are still in the default positions, hence, the labels overlap.
What am I missing in for updating the position of controls at the init stage in runtime? I've tried calling the UpdateLayout() method from both Initialize and the constructor of the control, alas to no avail.
Am i missing something obvious here?
EDIT:
As requested, I whipped up a quick test. My test control looks like so (Not including Designer code):
public partial class TestControl : UserControl
{
private Font _font;
[Browsable(true)]
public override Font Font
{
get
{
return this._font ?? SystemFonts.DefaultFont;
}
set
{
this._font = value;
this.DoLayout();
}
}
private void DoLayout()
{
this.label1.Font = this._font;
this.Size = new Size(label1.Width + textBox1.Width + 10,
label1.Height >= textBox1.Height ? label1.Height : textBox1.Height);
this.textBox1.Location = new Point(label1.Location.X + 5 + label1.Width, 1);
this.Update();
}
public TestControl()
{
InitializeComponent();
}
protected override void OnLayout(LayoutEventArgs e)
{
base.OnLayout(e);
DoLayout();
}
}
That works great at design time, but runtime, less so...
EDIT2:
So the above code doesn't entirely reflect the problem accurately, however, I have tried Jogy's suggestion of overriding the OnLayout method, and lo and behold, it works!
I'm relatively new to Custom Controls, so a rookie mistake on my part. This will definitely be committed to the long term memory.

Override OnLayout() method and call your UpdateLayout() there.

Thanks for supplying the code, I would provide the properties by reusing already available controls.
public override Font Font
{
get { return this.label1.Font; }
set
{
this.label1.Font = value;
// Additional code to update related controls.
}
}
Also be aware that the declaration of
private Font _font;
Delivers a non-initialized variable, and by using it in the "Do_Layout" might use a null value. Maybe change it to the following when using your code.
this.label1.Font = this.Font;

DataGridView - Suppress all word wrapping

I'm trying to implement a DataGridView that has smaller cell width than autosize does.
If you look really close at a autosized cell you'll notice that there is still some space that is not used to actually display the cell's content.
That's why I started to measure the content's width by myself via TextRenderer and then manually set the column's width.
The initial problem was that a "A" was displayed as "A..." long before the cell was actually "filled". The reason for that was cell.Style.WrapMode set to "nonSet". I was quite happy that DataGridViewTriState.True did work for that "A"-example.
But now I just noticed that if the String has multiple words ("A, B") the DataGridView tries to display the content to several lines long before the cell is actually "filled".
What I'm now looking for is either a way to delete that "padding" of the cell's content or fully suppress the word wrapping on a certain cell/column (= single line without the String's cut off).
Additionally I should admit that there are no hidden blanks on that Strings so trim has no effect at all.
Edit:
I randomly stumbled upon some colleagues code that seems to do kind of what I'm searching.
StringFormat format = new StringFormat(StringFormatFlags.NoClip);
The documentation says that strings have some rectangle around them that is bigger than the string itself. If the rectangle sticks out of the writeable area the string is wrapped. That code snippet suppresses that (default) behaviour.
The only problem is that this solution only seems to work for drawing strings. I didn't find a possibility to assign a stringformat object to a string.

Try This Code
dataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.DisplayedCells;
dataGridView1.DefaultCellStyle.WrapMode to DataGridView1TriState.True
Hope it helps you

Can you Try this code. That is working in my condition.
private void dataGridView1_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)
{
if (e.Value == null)
return;
var s = e.Graphics.MeasureString(e.Value.ToString(), dataGridView1.Font);
if (s.Width > dataGridView1.Columns[e.ColumnIndex].Width)
{
using (
Brush gridBrush = new SolidBrush(this.dataGridView1.GridColor),
backColorBrush = new SolidBrush(e.CellStyle.BackColor))
{
e.Graphics.FillRectangle(backColorBrush, e.CellBounds);
e.Graphics.DrawString(e.Value.ToString(), dataGridView1.Font, Brushes.Black, e.CellBounds, StringFormat.GenericDefault);
dataGridView1.Rows[e.RowIndex].Height = (int)(s.Height * Math.Ceiling(s.Width / dataGridView1.Columns[e.ColumnIndex].Width));
e.Handled = true;
}
}
}

Getting graphical Point of Listview items

I have a ListView control on my form and I am trying to get either a Point or even better, a Rectangle of each visible item in my ListView. Anyone know of a trick to do this?

foreach (ListViewItem item in myListView.Items)
{
Rectangle result = item.Bounds;
if(result.IntersectsWith(myListView.ClientRectangle))
{
//there you go
}
}
More about the Bounds you can find here.

What I have done is handle the ListView.DrawSubItem event, which gives me access to a DrawListViewSubItemEventArgs e instance with a e.Bounds property giving me the rectangle you are asking for.
If you don't want to do any drawing on your own just set e.DrawDefault = true;
Here is an example of the results:

How do I reclaim the space from the "Grip"

I've got a StatusStrip with a single ToolStripStatusLabel, Spring=true and a background color for notifications.
The problem is that there's an ugly gray square on the right side of the status strip. After fiddling for a while, I realized this is the sizing grip (I had is set to SizingGrip=false, GripStyle=Hidden). Yet even with it hidden, it still hogs the space. I can't get any content on the status strip to extend all the way to the right.
How would you work around this? Note I can't just set the backcolor of the StatusStrip because the Status Label changes colors and has some fading effects.

The StatusStrip.Padding property is borked, it returns the wrong value for Padding.Right if the sizing grip is disabled. You can fix it in your form constructor, like this:
public Form1() {
InitializeComponent();
statusStrip1.Padding = new Padding(statusStrip1.Padding.Left,
statusStrip1.Padding.Top, statusStrip1.Padding.Left, statusStrip1.Padding.Bottom);
}
Using the Left property to specify Right is the fix. Don't bother submitting this bug to Connect, they won't fix it.

Have a look at this blog entry on MSDN. The question was about changing the size of the sizing grip manually, and I think using the ToolStrip Renderer as suggested could work for you also.
The problem I have so far, is that it removes the background color on a status label in the StatusStrip, so it's not a solution yet, but it's a start.
public MyForm()
{
InitializeComponent();
statusStrip1.Renderer = new MyRenderer();
}
private class MyRenderer : ToolStripProfessionalRenderer
{
protected override void OnRenderStatusStripSizingGrip(ToolStripRenderEventArgs e)
{
// don't draw at all
}
}

I had following problem: when I set tsslSeparator.Spring = true, my right label disappeared immediately after tsslSeparator lost focus. The issue appeared when sizing grip was enabled. When it was disabled, everything worked just fine.
The solution was to set right margin for right label to something different than 0.
tsslLogging.Margin = new Padding(0, 3, 2, 2); // this is necessary for right alignment of status bar label
Hope this helps somebody.

If Microsoft isn't interesting in fixing it, it seems like a proper fix should handle all orientations, and ideally fix all Status Strips (see my answer to Get All Children for definition of GetAllChildren)
public static StatusStrip FixPadding(this StatusStrip ss) {
if (!ss.SizingGrip) {
var fixpad = ss.Padding;
if (ss.Orientation == Orientation.Horizontal) {
if (ss.RightToLeft == RightToLeft.No)
fixpad.Right = fixpad.Left;
else
fixpad.Left = fixpad.Right;
}
else
fixpad.Bottom = fixpad.Top;
ss.Padding = fixpad;
}
return ss;
}
public static void FixStatusStripPadding(this Form f) {
foreach (var ss in f.GetAllChildren().OfType<StatusStrip>())
ss.FixPadding();
}