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How to highlight or mark a node in a treeView in C #? [duplicate]

I'm making an interface to edit scenarios for a game. Basically it consists of events, which have nested conditions and actions. So, I planned on using two treeviews - one for selecting the event, and other for selecting the condition/action inside the event to edit.
Now, you see, if I select an event (in left treeview) and then try to select something in the right treeview, the left treeview will stop showing the blue selection rectangle. This is obviously bad because now the user doesn't know which event is he editing!
The only way I found to retain some sort of information about what is the current selection is by using SelectedImageIndex, but that's only one little image that will be different.
Is there any other way to highlight the treenode while there is no focus on the treeview? I know I can just use Graphics.DrawRectangle or something, but I heard that drawing should be done in Paint event and treeview has no paint event... So I guess if I draw it on the event of losing focus, and then drag the form out of the screen or something, it will be "erased"?
Anyway, please tell me if you got an idea (other than using a separate icon for selected and not selected treenode).

What you are looking for is the HideSelection property on the TreeView.
From MSDN:
Gets or sets a value indicating whether the selected tree node remains highlighted even when the tree view has lost the focus.
Link: http://msdn.microsoft.com/en-us/library/system.windows.forms.treeview.hideselection.aspx
Code:
TreeView.HideSelection = false;

It is still shown but only in light grey which depending on your screen and current setup can be near in visible!
Override the OnDrawNode event. So you create and new class (call it "SpecialTreeView") an inherit from the Microsoft TreeView like class SpecialTreeView : TreeView. Then you add the following event override:
protected override void OnDrawNode(DrawTreeNodeEventArgs e)
{
TreeNodeStates treeState = e.State;
Font treeFont = e.Node.NodeFont ?? e.Node.TreeView.Font;
// Colors.
Color foreColor = e.Node.ForeColor;
string strDeselectedColor = #"#6B6E77", strSelectedColor = #"#94C7FC";
Color selectedColor = System.Drawing.ColorTranslator.FromHtml(strSelectedColor);
Color deselectedColor = System.Drawing.ColorTranslator.FromHtml(strDeselectedColor);
// New brush.
SolidBrush selectedTreeBrush = new SolidBrush(selectedColor);
SolidBrush deselectedTreeBrush = new SolidBrush(deselectedColor);
// Set default font color.
if (foreColor == Color.Empty)
foreColor = e.Node.TreeView.ForeColor;
// Draw bounding box and fill.
if (e.Node == e.Node.TreeView.SelectedNode)
{
// Use appropriate brush depending on if the tree has focus.
if (this.Focused)
{
foreColor = SystemColors.HighlightText;
e.Graphics.FillRectangle(selectedTreeBrush, e.Bounds);
ControlPaint.DrawFocusRectangle(e.Graphics, e.Bounds, foreColor, SystemColors.Highlight);
TextRenderer.DrawText(e.Graphics, e.Node.Text, treeFont, e.Bounds,
foreColor, TextFormatFlags.GlyphOverhangPadding);
}
else
{
foreColor = SystemColors.HighlightText;
e.Graphics.FillRectangle(deselectedTreeBrush, e.Bounds);
ControlPaint.DrawFocusRectangle(e.Graphics, e.Bounds, foreColor, SystemColors.Highlight);
TextRenderer.DrawText(e.Graphics, e.Node.Text, treeFont, e.Bounds,
foreColor, TextFormatFlags.GlyphOverhangPadding);
}
}
else
{
if ((e.State & TreeNodeStates.Hot) == TreeNodeStates.Hot)
{
e.Graphics.FillRectangle(SystemBrushes.Window, e.Bounds);
TextRenderer.DrawText(e.Graphics, e.Node.Text, hotFont, e.Bounds,
System.Drawing.Color.Black, TextFormatFlags.GlyphOverhangPadding);
}
else
{
e.Graphics.FillRectangle(SystemBrushes.Window, e.Bounds);
TextRenderer.DrawText(e.Graphics, e.Node.Text, treeFont, e.Bounds,
foreColor, TextFormatFlags.GlyphOverhangPadding);
}
}
}
Compile the code and you should see "SpecialTreeView" in your tool box in the designer. Replace your TreeView with this new one using the same name and the only thing that will be different is the selection colours. When selected it will be selectedColor, when not selected the deselectedColor.
I hope this helps.

Fast solution:
Set the properties:
HideSelection = false;
DrawMode = TreeViewDrawMode.OwnerDrawText;
Then in the DrawNode event handler simply do:
private void treeView1_DrawNode(object sender, DrawTreeNodeEventArgs e) {
e.DrawDefault = true;
}
On Windwos 7 this restores the old rendering, including the dashed box around the selection (which actually looks a bit outdated). The text will be white with focus, and black without focus. The background stays blue and visible.
This answer is not new, the others also contain these steps, but this is the minimal needed (at least in Windows 7, didn't test other OS's).

Not absolutely perfect solution, but quite near:
treeView.HideSelection = false;
treeView.DrawMode = TreeViewDrawMode.OwnerDrawText;
treeView.DrawNode += (o, e) =>
{
if (!e.Node.TreeView.Focused && e.Node == e.Node.TreeView.SelectedNode)
{
Font treeFont = e.Node.NodeFont ?? e.Node.TreeView.Font;
e.Graphics.FillRectangle(Brushes.Gray, e.Bounds);
ControlPaint.DrawFocusRectangle(e.Graphics, e.Bounds, SystemColors.HighlightText, SystemColors.Highlight);
TextRenderer.DrawText(e.Graphics, e.Node.Text, treeFont, e.Bounds, SystemColors.HighlightText, TextFormatFlags.GlyphOverhangPadding);
}
else
e.DrawDefault = true;
};
treeView.MouseDown += (o, e) =>
{
TreeNode node = treeView.GetNodeAt(e.X, e.Y);
if (node != null && node.Bounds.Contains(e.X, e.Y))
treeView.SelectedNode = node;
};

Found an easier way:
Set TreeView.HideSelection = True
Add the following to TreeView.AfterSelect-Callback:
private void treeViewBenutzerverwaltung_AfterSelect(object sender, TreeViewEventArgs e)
{
// Select new node
e.Node.BackColor = SystemColors.Highlight;
e.Node.ForeColor = SystemColors.HighlightText;
if (_lastSelectedNode != null)
{
// Deselect old node
_lastSelectedNode.BackColor = SystemColors.Window;
_lastSelectedNode.ForeColor = SystemColors.WindowText;
}
_lastSelectedNode = e.Node;
}

Similar to the previous one but with the appearance more similar to the Win10 standard:
treeView.HideSelection = false;
treeView.DrawMode = TreeViewDrawMode.OwnerDrawText;
treeView.DrawNode += (o, e) =>
{
if (e.Node == e.Node.TreeView.SelectedNode)
{
Font font = e.Node.NodeFont ?? e.Node.TreeView.Font;
Rectangle r = e.Bounds;
r.Offset(0, 1);
Brush brush = e.Node.TreeView.Focused ? SystemBrushes.Highlight : Brushes.Gray;
e.Graphics.FillRectangle(brush, e.Bounds);
TextRenderer.DrawText(e.Graphics, e.Node.Text, font, r, SystemColors.HighlightText, TextFormatFlags.GlyphOverhangPadding);
}
else
e.DrawDefault = true;
};
treeView.MouseDown += (o, e) =>
{
TreeNode node = treeView.GetNodeAt(e.Location);
if (node != null && node.Bounds.Contains(e.Location)) treeView.SelectedNode = node;
};

combo box - drop down list [duplicate]

This question already has answers here:
Colour Individual Items in a winforms ComboBox?
(4 answers)
Closed 8 years ago.
i was wondering if it is possible to create a combo box (drop down list) and to paint specific cells in the drop down list.
so, if i have five items in the drop down list, the second item and the last item will be painted in blue for example and the others in gray..
is it possible?
System.Windows.Forms.ComboBox comboBox;
comboBox = new System.Windows.Forms.ComboBox();
comboBox.AllowDrop = true;
comboBox.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
comboBox.FormattingEnabled = true;
comboBox.Items.AddRange(excel.getPlanNames());
comboBox.Location = new System.Drawing.Point(x, y);
comboBox.Name = "comboBox1";
comboBox.Size = new System.Drawing.Size(sizeX, sizeY);
comboBox.TabIndex = 0;
group.Controls.Add(comboBox);
thank's for any help..

You can use the DrawItem Event.
First you have to set the DrawMode of the ComboBox to OwnerDrawFixed
Then you set the DrawItem to something like the following:
private void comboBox1_DrawItem(object sender, DrawItemEventArgs e)
{
Font font = (sender as ComboBox).Font;
Brush backgroundColor;
Brush textColor;
if (e.Index == 1 || e.Index == 3)
{
if ((e.State & DrawItemState.Selected) == DrawItemState.Selected)
{
backgroundColor = Brushes.Red;
textColor = Brushes.Black;
}
else
{
backgroundColor = Brushes.Green;
textColor = Brushes.Black;
}
}
else
{
if ((e.State & DrawItemState.Selected) == DrawItemState.Selected)
{
backgroundColor = SystemBrushes.Highlight;
textColor = SystemBrushes.HighlightText;
}
else
{
backgroundColor = SystemBrushes.Window;
textColor = SystemBrushes.WindowText;
}
}
e.Graphics.FillRectangle(backgroundColor, e.Bounds);
e.Graphics.DrawString((sender as ComboBox).Items[e.Index].ToString(), font, textColor, e.Bounds);
}
This example will make the default background colour Green with black text, and the highlighted item will have a red background and black text, of the items at indexes 1 and 3.
You could also set the font of individual items using the font variable.

C# ComboBox Item Highlight not working with DrawItem

Using the example from the marked answer in this post i came up with this.
private void comboBox1_DrawItem(object sender, DrawItemEventArgs e)
{
using (DBDataContext data = new DBDataContext())
{
var query = (from a in data.Programs
where a.IsCurrentApplication == 1
select a.Name).Distinct();
e.DrawBackground();
string text = ((ComboBox)sender).Items[e.Index].ToString();
Brush brush;
if (query.Contains(text))
{
brush = Brushes.Green;
}
else
{
brush = Brushes.Black;
}
e.Graphics.DrawString(text,
((Control)sender).Font,
brush,
e.Bounds.X, e.Bounds.Y);
}
}
What I'm doing is querying a database for applications with a flag. If the flag is true (1), then I change the text of the combobox item to Green. My issue here is that once all the items are drawn. When I hover my cursor of an item, it doesn't highlight. It does however change the darkness of the text slightly. Is there a way i can get the highlighting to work?

As I said in the comment, when drawing we should avoid as much non-drawing code as possible. In some cases doing so can cause some flicker and in some cases the result is unpredicted. So we should always place such a code outside the drawing route. The query in your code should be placed outside your DrawItem event handler something like this:
public Form1(){
InitializeComponent();
using (DBDataContext data = new DBDataContext()) {
query = (from a in data.Programs
where a.IsCurrentApplication == 1
select a.Name).Distinct().ToList();//execute the query right
}
}
IEnumerable<string> query;
private void comboBox1_DrawItem(object sender, DrawItemEventArgs e) {
var combo = sender as ComboBox;
e.DrawBackground();
string text = combo.Items[e.Index].ToString();
Brush brush = query.Contains(text) ? Brushes.Green : Brushes.Black;
e.Graphics.DrawString(text, e.Font, brush, e.Bounds);
}

Changing the Color of ComboBox highlighting

I am trying to work around changing the color of highlighting in a ComboBox dropdown on a C# Windows Forms application.
I have searched the whole web for an answer, and the best option i found so far was to draw a rectangle of the desired color when the item that is selected is being drawn.
Class Search
{
Public Search()
{
}
private void addFilter()
{
ComboBox field = new ComboBox();
field.Items.AddRange(new string[] { "Item1", "item2" });
field.Text = "Item1";
field.DropDownStyle = ComboBoxStyle.DropDownList;
field.FlatStyle = FlatStyle.Flat;
field.BackColor = Color.FromArgb(235, 235, 235);
field.DrawMode = DrawMode.OwnerDrawFixed;
field.DrawItem += field_DrawItem;
}
private void field_DrawItem(object sender, DrawItemEventArgs e)
{
if (e.Index >= 0)
{
ComboBox combo = sender as ComboBox;
if (e.Index == combo.SelectedIndex)
e.Graphics.FillRectangle(new SolidBrush(Color.Gray),
e.Bounds
);
else
e.Graphics.FillRectangle(new SolidBrush(combo.BackColor),
e.Bounds
);
e.Graphics.DrawString(combo.Items[e.Index].ToString(), e.Font,
new SolidBrush(combo.ForeColor),
new Point(e.Bounds.X, e.Bounds.Y)
);
}
}
}
The problem with this code, is that once another Item in the dropdown is selected, the other Item I draw a rectangle is still with the color i want to highlight.
Then i tried to save the last Item drawn and redraw it:
Class Search
{
private DrawItemEventArgs lastDrawn;
Public Search()
{
lastDrawn = null;
}
private void addFilter()
{
ComboBox field = new ComboBox();
field.Items.AddRange(new string[] { "Item1", "item2" });
field.Text = "Item1";
field.DropDownStyle = ComboBoxStyle.DropDownList;
field.FlatStyle = FlatStyle.Flat;
field.BackColor = Color.FromArgb(235, 235, 235);
field.DrawMode = DrawMode.OwnerDrawFixed;
field.DrawItem += field_DrawItem;
}
private void field_DrawItem(object sender, DrawItemEventArgs e)
{
if (e.Index >= 0)
{
ComboBox combo = sender as ComboBox;
if (e.Index == combo.SelectedIndex)
{
e.Graphics.FillRectangle(new SolidBrush(Color.Gray), e.Bounds);
if(lastDrawn != null)
lastDrawn.Graphics.FillRectangle(new SolidBrush(combo.BackColor),
lastDrawn.Bounds
);
lastDrawn = e;
}
else
e.Graphics.FillRectangle(new SolidBrush(combo.BackColor),
e.Bounds
);
e.Graphics.DrawString(combo.Items[e.Index].ToString(), e.Font,
new SolidBrush(combo.ForeColor),
new Point(e.Bounds.X, e.Bounds.Y)
);
}
}
}
This line returns an error because of lastDrawn.Bounds (incompatible type)
lastDrawn.Graphics.FillRectangle(new SolidBrush(combo.BackColor),
lastDrawn.Bounds
);
I am feeling that changing the highlight color of the dropdown is impossible.
Thanks in advance!

In case you are using the ComboBox in more than one place in your project, it will not make sense to repeat the same code for DrawItem event over and over again. Just add this class to your project and you will have a new ComboBox control that has the HightlightColor property which will makes it easier to use the control all over the project:
class AdvancedComboBox : ComboBox
{
new public System.Windows.Forms.DrawMode DrawMode { get; set; }
public Color HighlightColor { get; set; }
public AdvancedComboBox()
{
base.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawFixed;
this.HighlightColor = Color.Gray;
this.DrawItem += new DrawItemEventHandler(AdvancedComboBox_DrawItem);
}
void AdvancedComboBox_DrawItem(object sender, DrawItemEventArgs e)
{
if (e.Index < 0)
return;
ComboBox combo = sender as ComboBox;
if ((e.State & DrawItemState.Selected) == DrawItemState.Selected)
e.Graphics.FillRectangle(new SolidBrush(HighlightColor),
e.Bounds);
else
e.Graphics.FillRectangle(new SolidBrush(combo.BackColor),
e.Bounds);
e.Graphics.DrawString(combo.Items[e.Index].ToString(), e.Font,
new SolidBrush(combo.ForeColor),
new Point(e.Bounds.X, e.Bounds.Y));
e.DrawFocusRectangle();
}
}

Change the borderColor of the TextBox

How can I change the BorderColor of the Textbox when a user Clicks on it or focuses on it?

You can handle WM_NCPAINT message of TextBox and draw a border on the non-client area of control if the control has focus. You can use any color to draw border:
using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;
public class ExTextBox : TextBox
{
[DllImport("user32")]
private static extern IntPtr GetWindowDC(IntPtr hwnd);
private const int WM_NCPAINT = 0x85;
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
if (m.Msg == WM_NCPAINT && this.Focused)
{
var dc = GetWindowDC(Handle);
using (Graphics g = Graphics.FromHdc(dc))
{
g.DrawRectangle(Pens.Red, 0, 0, Width - 1, Height - 1);
}
}
}
}
Result
The painting of borders while the control is focused is completely flicker-free:
BorderColor property for TextBox
In the current post I just change the border color on focus. You can also add a BorderColor property to the control. Then you can change border-color based on your requirement at design-time or run-time. I've posted a more completed version of TextBox which has BorderColor property:
in the following post:
BorderColor property for TextBox

try this
bool focus = false;
private void Form1_Paint(object sender, PaintEventArgs e)
{
if (focus)
{
textBox1.BorderStyle = BorderStyle.None;
Pen p = new Pen(Color.Red);
Graphics g = e.Graphics;
int variance = 3;
g.DrawRectangle(p, new Rectangle(textBox1.Location.X - variance, textBox1.Location.Y - variance, textBox1.Width + variance, textBox1.Height +variance ));
}
else
{
textBox1.BorderStyle = BorderStyle.FixedSingle;
}
}
private void textBox1_Enter(object sender, EventArgs e)
{
focus = true;
this.Refresh();
}
private void textBox1_Leave(object sender, EventArgs e)
{
focus = false;
this.Refresh();
}

This is an ultimate solution to set the border color of a TextBox:
public class BorderedTextBox : UserControl
{
TextBox textBox;
public BorderedTextBox()
{
textBox = new TextBox()
{
BorderStyle = BorderStyle.FixedSingle,
Location = new Point(-1, -1),
Anchor = AnchorStyles.Top | AnchorStyles.Bottom |
AnchorStyles.Left | AnchorStyles.Right
};
Control container = new ContainerControl()
{
Dock = DockStyle.Fill,
Padding = new Padding(-1)
};
container.Controls.Add(textBox);
this.Controls.Add(container);
DefaultBorderColor = SystemColors.ControlDark;
FocusedBorderColor = Color.Red;
BackColor = DefaultBorderColor;
Padding = new Padding(1);
Size = textBox.Size;
}
public Color DefaultBorderColor { get; set; }
public Color FocusedBorderColor { get; set; }
public override string Text
{
get { return textBox.Text; }
set { textBox.Text = value; }
}
protected override void OnEnter(EventArgs e)
{
BackColor = FocusedBorderColor;
base.OnEnter(e);
}
protected override void OnLeave(EventArgs e)
{
BackColor = DefaultBorderColor;
base.OnLeave(e);
}
protected override void SetBoundsCore(int x, int y,
int width, int height, BoundsSpecified specified)
{
base.SetBoundsCore(x, y, width, textBox.PreferredHeight, specified);
}
}

WinForms was never good at this and it's a bit of a pain.
One way you can try is by embedding a TextBox in a Panel and then manage the drawing based on focus from there:
public class BorderTextBox : Panel {
private Color _NormalBorderColor = Color.Gray;
private Color _FocusBorderColor = Color.Blue;
public TextBox EditBox;
public BorderTextBox() {
this.DoubleBuffered = true;
this.Padding = new Padding(2);
EditBox = new TextBox();
EditBox.AutoSize = false;
EditBox.BorderStyle = BorderStyle.None;
EditBox.Dock = DockStyle.Fill;
EditBox.Enter += new EventHandler(EditBox_Refresh);
EditBox.Leave += new EventHandler(EditBox_Refresh);
EditBox.Resize += new EventHandler(EditBox_Refresh);
this.Controls.Add(EditBox);
}
private void EditBox_Refresh(object sender, EventArgs e) {
this.Invalidate();
}
protected override void OnPaint(PaintEventArgs e) {
e.Graphics.Clear(SystemColors.Window);
using (Pen borderPen = new Pen(this.EditBox.Focused ? _FocusBorderColor : _NormalBorderColor)) {
e.Graphics.DrawRectangle(borderPen, new Rectangle(0, 0, this.ClientSize.Width - 1, this.ClientSize.Height - 1));
}
base.OnPaint(e);
}
}

Using OnPaint to draw a custom border on your controls is fine. But know how to use OnPaint to keep efficiency up, and render time to a minimum. Read this if you are experiencing a laggy GUI while using custom paint routines: What is the right way to use OnPaint in .Net applications?
Because the accepted answer of PraVn may seem simple, but is actually inefficient. Using a custom control, like the ones posted in the answers above is way better.
Maybe the performance is not an issue in your application, because it is small, but for larger applications with a lot of custom OnPaint routines it is a wrong approach to use the way PraVn showed.

set Text box Border style to None
then write this code to container form "paint" event
private void Form1_Paint(object sender, PaintEventArgs e)
{
System.Drawing.Rectangle rect = new Rectangle(TextBox1.Location.X,
TextBox1.Location.Y, TextBox1.ClientSize.Width, TextBox1.ClientSize.Height);
rect.Inflate(1, 1); // border thickness
System.Windows.Forms.ControlPaint.DrawBorder(e.Graphics, rect,
Color.DeepSkyBlue, ButtonBorderStyle.Solid);
}

With PictureBox1
.Visible = False
.Width = TextBox1.Width + 4
.Height = TextBox1.Height + 4
.Left = TextBox1.Left - 2
.Top = TextBox1.Top - 2
.SendToBack()
.Visible = True
End With

Here is my complete Flat TextBox control that supports themes including custom border colors in normal and focused states.
The control uses the same concept mentioned by Reza Aghaei https://stackoverflow.com/a/38405319/5514131 ,however the FlatTextBox control is more customizable and flicker-free.
The control handles the WM_NCPAINT window message in a better way to help eliminate flicker.
Protected Overrides Sub WndProc(ByRef m As Message)
If m.Msg = WindowMessage.WM_NCPAINT AndAlso _drawBorder AndAlso Not DesignMode Then 'Draw the control border
Dim w As Integer
Dim h As Integer
Dim clip As Rectangle
Dim hdc As IntPtr
Dim clientRect As RECT = Nothing
GetClientRect(Handle, clientRect)
Dim windowRect As RECT = Nothing
GetWindowRect(Handle, windowRect)
w = windowRect.Right - windowRect.Left
h = windowRect.Bottom - windowRect.Top
clip = New Rectangle(CInt((w - clientRect.Right) / 2), CInt((h - clientRect.Bottom) / 2), clientRect.Right, clientRect.Bottom)
hdc = GetWindowDC(Handle)
Using g As Graphics = Graphics.FromHdc(hdc)
g.SetClip(clip, CombineMode.Exclude)
Using sb = New SolidBrush(BackColor)
g.FillRectangle(sb, 0, 0, w, h)
End Using
Using p = New Pen(If(Focused, _borderActiveColor, _borderNormalColor), BORDER_WIDTH)
g.DrawRectangle(p, 0, 0, w - 1, h - 1)
End Using
End Using
ReleaseDC(Handle, hdc)
Return
End If
MyBase.WndProc(m)
End Sub
I have removed the default BorderStyle property and replaced it with a simple boolean DrawBorder property that controls whether to draw a border around the control or not.
Use the BorderNormalColor property to specify the border color when the TextBox has no focus, and the BorderActiveColor property to specify the border color when the control receives focus.
The FlatTextBox comes with two themes VS2019 Dark and VS2019 Light, use the Theme property to switch between them.
Complete FlatTextBox control code written in VB.NET
https://gist.github.com/ahmedosama007/37fe2004183a51a4ea0b4a6dcb554176