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How to create a Windows Form in C# that can be seen only but can not be clicked or brought to focus

I am working on an Accessibility Screen Reader application that will put a rectangle highlighter around the element that is selected on the Focused program. I am able to detect the currently focused AutomationElement, and get its BoundingRectangle property. (How is Spy++ element highlighting working?)
Given a rectangle's topLeftCorner and bottomRightCorner, I am trying to draw a highlighter rectangle using the code below:
internal class HighlighterForm : Form
{
public HighlighterForm(Point topLeftCorner, Point bottomRightCorner, float borderWidth=5){
int length = bottomRightCorner.X - topLeftCorner.X;
int width = bottomRightCorner.Y - topLeftCorner.Y;
this.Text = "Highlighter";
this.FormBorderStyle = FormBorderStyle.None;
this.StartPosition = FormStartPosition.Manual;
this.Location = new Point(topLeftCorner.X, topLeftCorner.Y);
this.TopLevel = true;
this.TopMost = true;
this.Size = new Size(length, width);
// Make the Form background transparent
this.TransparencyKey = Color.Turquoise;
this.BackColor = Color.Turquoise;
this.Paint += (o, e) => {
Graphics g = e.Graphics;
using (Pen selPen = new Pen(Color.Blue, borderWidth*2))
{
g.DrawRectangle(selPen, 0, 0, length, width);
}
};
}
}
And then, I am using the following snippet to create the highlighter:
Point topLeftCorner = new Point(10, 50);
Point bottomRightCorner = new Point(600, 200);
HighlighterForm highlighter = new HighlighterForm(topLeftCorner, bottomRightCorner);
highlighter.ShowDialog();
This can draw a rectangle anywhere on the screen, but the problem is that this form does not let any contents found on an app under the rectangle to be selected. For example, if the currently selected element is a page from Microsoft Word, then the user won't be able to select a paragraph because the rectangle is on top.
How can I make sure the rectangle is there only visually and cannot be interacted with or clicked on?

Styling Windows Form Tab

I am creating windows Tabbed Application. Everything is good but the tabs are quiet faded and borders are very dull. I have tried changing the border style to 3D as well but no effect. Below is the screenshot
There are forums where people have suggested to use third party library to make Google Chrome type tabs. But I want the native way to get beautiful tabs.

You can take control of how the tabs are drawn by setting the DrawMode = TabDrawMode.OwnerDrawFixed. The example below assumes you have a TabControl named tabControl1 on the form, this will add a new tab with a blue box.
private Rectangle myTabRect;
private Rectangle myInsideRect;
private Rectangle myOutsideRect;
public Form1()
{
InitializeComponent();
TabPage tabPage1 = new TabPage();
// Sets the tabs to be drawn by the parent window Form1.
// OwnerDrawFixed allows access to DrawItem.
tabControl1.DrawMode = TabDrawMode.OwnerDrawFixed;
tabControl1.Controls.Add(tabPage1);
tabControl1.Location = new Point(25, 25);
tabControl1.Size = new Size(250, 250);
tabPage1.TabIndex = 0;
myTabRect = tabControl1.GetTabRect(0);
myInsideRect = new Rectangle(tabControl1.DisplayRectangle.X -1, tabControl1.DisplayRectangle.Y -1, tabControl1.DisplayRectangle.Width + 1, tabControl1.DisplayRectangle.Height + 1);
myOutsideRect = tabControl1.ClientRectangle;
myOutsideRect.Width--;
myOutsideRect.Height--;
ClientSize = new Size(300, 500);
Controls.Add(tabControl1);
tabControl1.DrawItem += new DrawItemEventHandler(OnDrawItem);
}
private void OnDrawItem(object sender, DrawItemEventArgs e)
{
// Draw your tab graphics here
Graphics g = e.Graphics;
Pen p = new Pen(Color.Blue);
g.DrawRectangle(p, myTabRect);
p = new Pen(Color.Red);
g.DrawRectangle(p, myInsideRect);
p = new Pen(Color.Green);
g.DrawRectangle(p, myOutsideRect);
}
You can draw whatever style you like into the graphic context, add text, images, etc

C# vertical tab control with horizontal text

I want to display some information in tab control This is what I want.
I have used the methods that I found on your side to make changes in properties of tab control and using Draw Event but the output is not like what i needed.The output comes likeThis is what I am getting..
I want the text to be horizontal. Also my VS is 2008

I followed these instructions in VB and converted them to C#. Worked for me. Basically in tab control properties set the following:
Alignment = Left
SizeMode = Fixed
ItemSize = 30, 120: Width = 30 Height = 120
DrawMode = OwnerDrawFixed
Then you have to handle DrawItem event like that:
private void tabControl1_DrawItem(object sender, DrawItemEventArgs e)
{
var g = e.Graphics;
var text = this.tabControl1.TabPages[e.Index].Text;
var sizeText = g.MeasureString(text, this.tabControl1.Font);
var x = e.Bounds.Left + 3;
var y = e.Bounds.Top + (e.Bounds.Height - sizeText.Height) / 2;
g.DrawString(text, this.tabControl1.Font, Brushes.Black, x, y);
}
And the result is:

Set the SizeMode property to Fixed, so that all tabs are the same width.
Set the ItemSize property to the preferred fixed size for the tabs. Keep in mind that the ItemSize property behaves as though the tabs were on top, although they are left-aligned. As a result, in order to make the tabs wider, you must change the Height property, and in order to make them taller, you must change the Width property. [I set the ItemSize as: 25, 150].
Set the DrawMode property to OwnerDrawFixed.
private void tabControl1_DrawItem(object sender, DrawItemEventArgs e)
{
Graphics g = e.Graphics;
Brush _textBrush;
// Get the item from the collection.
TabPage _tabPage = tabControl1.TabPages[e.Index];
// Get the real bounds for the tab rectangle.
Rectangle _tabBounds = tabControl1.GetTabRect(e.Index);
if (e.State == DrawItemState.Selected)
{
// Draw a different background color, and don't paint a focus rectangle.
_textBrush = new SolidBrush(Color.Red);
g.FillRectangle(Brushes.Gray, e.Bounds);
}
else
{
_textBrush = new System.Drawing.SolidBrush(e.ForeColor);
e.DrawBackground();
}
// Use our own font.
Font _tabFont = new Font("Arial", (float)10.0, FontStyle.Bold, GraphicsUnit.Pixel);
// Draw string. Center the text.
StringFormat _stringFlags = new StringFormat();
_stringFlags.Alignment = StringAlignment.Center;
_stringFlags.LineAlignment = StringAlignment.Center;
g.DrawString(_tabPage.Text, _tabFont, _textBrush, _tabBounds, new StringFormat(_stringFlags));
}

Change Specific Tab Page Tab Color / Losing formatting when selecting DrawMode=OwnerDrawFixed

While trying to change the color of the tab based on button click event I came across this page:
Set TabPage Header Color
It appears to work, however I lost all the other formatting of my tabs and they now appear blank after I set the DrawMode=OwnerDrawFixed. How do I set the color of the tab of a specific page and still show the tabs as normal?
Code:
private void button3_Click(object sender, EventArgs e)
{
this.TabControlMain.DrawItem += new System.Windows.Forms.DrawItemEventHandler(this.TabControlMain_DrawItem);
SetTabHeader (tabDownload, System.Drawing.Color.Green);
}
private Dictionary<TabPage, Color> TabColors = new Dictionary<TabPage, Color>();
private void SetTabHeader(TabPage page, Color color)
{
TabColors[page] = color;
tabDownload.Invalidate();
}
private void TabControlMain_DrawItem(object sender, DrawItemEventArgs e)
{
//e.DrawBackground();
using (Brush br = new SolidBrush(TabColors[TabControlMain.TabPages[e.Index]]))
{
e.Graphics.FillRectangle(br, e.Bounds);
SizeF sz = e.Graphics.MeasureString(TabControlMain.TabPages[e.Index].Text, e.Font);
e.Graphics.DrawString(TabControlMain.TabPages[e.Index].Text, e.Font, Brushes.Black, e.Bounds.Left + (e.Bounds.Width - sz.Width) / 2, e.Bounds.Top + (e.Bounds.Height - sz.Height) / 2 + 1);
Rectangle rect = e.Bounds;
rect.Offset(0, 1);
rect.Inflate(0, -1);
e.Graphics.DrawRectangle(Pens.DarkGray, rect);
e.DrawFocusRectangle();
}
}
Below is a screenshot

Use Y(et)A(nother)TabControl
Gives you the possibly to draw own custom headers:
public override void DrawTab( Color foreColor,
Color backColor,
Color highlightColor,
Color shadowColor,
Color borderColor,
bool active,
bool mouseOver,
DockStyle dock,
Graphics graphics,
SizeF tabSize )
{
if( active )
{
Pen p = new Pen( borderColor );
graphics.DrawRectangle( p, 0, 0, tabSize.Width, tabSize.Height );
p.Dispose();
}
else
{
Brush b = Brushes.Peru;
float dif = tabSize.Height / 4.0f;
RectangleF r = new RectangleF( 0.0f, dif,
tabSize.Width, tabSize.Height - dif - dif );
graphics.FillRectangle( b, r );
}
}

In principle your code works, if not fine then at least sufficiently.
But you need to fix a few simple issues:
Of course, if your Tab is OwnerDrawn you need to do it from the start, not just after pressing the Button! So hook up the event right from the start, best in the Property-Event Tab so that it is placed in the Desgner.cs file where it belongs.
Now the Tabs are drawn and their Label texts show.
If you want to change a color you need to Invalidate the Tab Control, not the TabPage!
so change
tabDownload.Invalidate();
to
TabControlMain.Invalidate();
To make the example complete I have done only this:
private void Form1_Load(object sender, EventArgs e)
{
foreach (TabPage tp in TabControlMain.TabPages)
TabColors.Add(tp, tp.BackColor);
}
This sets all Tab colors in the Dictionary to the Colors of the Pages.
The code to draw the FocusRectangle could be improved.
First set the Padding like this:
this.TabControlMain.Padding = new System.Drawing.Point(10, 4);
This gives us enough room to draw a nice FocusRectangle..
Then change the code to draw it only on the selected Tab, maybe like this:
if (TabControlMain.SelectedIndex == e.Index)
using (Pen pen = new Pen(Color.Gray))
{
pen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dot;
Rectangle rect = e.Bounds;
rect.Offset(0, 1);
rect.Inflate(-3,-2);
e.Graphics.DrawRectangle(pen, rect);
}
Now it looks like this:
Of course managing the colors is up to you..

Draw Border around ListBox

How would I go about drawing a border with a specified width and color around a listbox?
Can this be done without overriding the OnPaint method?

Following Neutone's suggestion, here is a handy function to add and remove a Panel-based border around any control, even if it is nested..
Simply pass in the Color and size you want, and if you want a BorderStyle. To remove it again pass in Color.Transparent!
void setBorder(Control ctl, Color col, int width, BorderStyle style)
{
if (col == Color.Transparent)
{
Panel pan = ctl.Parent as Panel;
if (pan == null) { throw new Exception("control not in border panel!");}
ctl.Location = new Point(pan.Left + width, pan.Top + width);
ctl.Parent = pan.Parent;
pan.Dispose();
}
else
{
Panel pan = new Panel();
pan.BorderStyle = style;
pan.Size = new Size(ctl.Width + width * 2, ctl.Height + width * 2);
pan.Location = new Point(ctl.Left - width, ctl.Top - width);
pan.BackColor = col;
pan.Parent = ctl.Parent;
ctl.Parent = pan;
ctl.Location = new Point(width, width);
}
}

You can place a list box within a panel and have the panel serve as a border. The panel backcolor can be used to create a colored border. This doesn't require much code. Having a colored border around a form component can be an effective way of conveying status.

The problem with the ListBox control is that it does not raise the OnPaint method so you can not use it to draw a border around the control.
There are two methods to paint a custom border around the ListBox:
Use SetStyle(ControlStyles.UserPaint, True) in the constructor, then you can use the OnPaint method to draw the border.
Override WndProc method that handles operating system messages identified in the Message structure.
I used the last method to paint a custom border around the control, this will eliminate the need to use a Panel to provide a custom border for the ListBox.
public partial class MyListBox : ListBox
{
public MyListBox()
{
// SetStyle(ControlStyles.UserPaint, True)
BorderStyle = BorderStyle.None;
}
protected override void WndProc(ref Message m)
{
base.WndProc(m);
var switchExpr = m.Msg;
switch (switchExpr)
{
case 0xF:
{
Graphics g = this.CreateGraphics;
g.SmoothingMode = Drawing2D.SmoothingMode.Default;
int borderWidth = 4;
Rectangle rect = ClientRectangle;
using (var p = new Pen(Color.Red, borderWidth) { Alignment = Drawing2D.PenAlignment.Center })
{
g.DrawRectangle(p, rect);
}
break;
}
default:
{
break;
}
}
}
}