Develop Reference

Customizing Border and Button of the DateTimePicker

Goal is to create DateTimePicker similar to the screen shot of this question.
First attempt overriding OnPaint:
public class MyDateTimePicker : DateTimePicker
{
private Image _image;
public MyDateTimePicker() : base()
{
SetStyle(ControlStyles.UserPaint | ControlStyles.ResizeRedraw |
ControlStyles.DoubleBuffer | ControlStyles.AllPaintingInWmPaint, true);
}
[Browsable(true)]
public override Color BackColor
{
get
{
return base.BackColor;
}
set
{
base.BackColor = value;
}
}
[Category("Appearance")]
public Color BorderColor { get; set; } = Color.Black;
[Category("Appearance")]
public Color TextColor { get; set; } = Color.Black;
[Category("Appearance")]
public Image Image
{
get
{
return _image;
}
set
{
_image = value;
Invalidate();
}
}
protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
{
e.Graphics.TextRenderingHint = System.Drawing.Text.TextRenderingHint.ClearTypeGridFit;
// Fill the Background
e.Graphics.FillRectangle(new SolidBrush(this.BackColor), 0, 0, ClientRectangle.Width, ClientRectangle.Height);
// Draw DateTime text
e.Graphics.DrawString(this.Text, this.Font, new SolidBrush(TextColor), 5, 2);
// Draw Icon
if (_image != null)
{
Rectangle im_rect = new Rectangle(ClientRectangle.Width - 20, 2, ClientRectangle.Height - 4, ClientRectangle.Height - 4);
e.Graphics.DrawImage(_image, im_rect);
}
// Draw Border
e.Graphics.DrawRectangle(Pens.Black, new Rectangle(0, 0, ClientRectangle.Width - 1, ClientRectangle.Height - 1));
}
}
This solution has the following issues: date fields are not clickable, text artifacts when changing date with arrow keys, narrow clickable area of the button.
Second solution overriding WndProc:
public class MyDateTimePicker : DateTimePicker
{
private const int WM_PAINT = 0x000F;
private Color _borderColor = Color.Black;
public MyDateTimePicker() { }
[Category("Appearance")]
public Color BorderColor
{
get { return _borderColor; }
set
{
if (_borderColor != value)
{
_borderColor = value;
this.Invalidate();
}
}
}
protected override void WndProc(ref Message m)
{
switch (m.Msg)
{
case WM_PAINT:
base.WndProc(ref m);
using (var g = Graphics.FromHwnd(m.HWnd))
{
var rect = new Rectangle(0, 0, this.ClientSize.Width - 1, this.ClientSize.Height - 1);
g.DrawRectangle(new Pen(this.BorderColor), rect);
}
m.Result = IntPtr.Zero;
break;
default:
base.WndProc(ref m);
break;
}
}
}
This solution lacks the customization of the button. Maybe anyone knows how to customize button in this way, or how to solve issues of the first solution?
Also if it is possible I would like to change the height of DateTimePicker to match height of ComboBox (currently they differ by 1px).

You can handle WM_PAINT and draw the border and button yourself. To get the accurate size of the dropdown, send DTM_GETDATETIMEPICKERINFO message.
The width of the dropdown button may vary depending to the size of the control and the space required by the text of the control:
Flat DateTimePicker
using System;
using System.ComponentModel;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;
public class FlatDateTimePicker : DateTimePicker
{
public FlatDateTimePicker()
{
SetStyle(ControlStyles.ResizeRedraw |
ControlStyles.OptimizedDoubleBuffer, true);
}
private Color borderColor = Color.DeepSkyBlue;
[DefaultValue(typeof(Color), "RoyalBlue")]
public Color BorderColor
{
get { return borderColor; }
set
{
if (borderColor != value)
{
borderColor = value;
Invalidate();
}
}
}
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
if (m.Msg == WM_PAINT)
{
var info = new DATETIMEPICKERINFO();
info.cbSize = Marshal.SizeOf(info);
SendMessage(Handle, DTM_GETDATETIMEPICKERINFO, IntPtr.Zero, ref info);
using (var g = Graphics.FromHwndInternal(Handle))
{
var clientRect = new Rectangle(0,0,Width, Height);
var buttonWidth = info.rcButton.R - info.rcButton.L;
var dropDownRect = new Rectangle(info.rcButton.L, info.rcButton.T,
buttonWidth, clientRect.Height);
if (RightToLeft == RightToLeft.Yes && RightToLeftLayout == true)
{
dropDownRect.X = clientRect.Width - dropDownRect.Right;
dropDownRect.Width += 1;
}
var middle = new Point(dropDownRect.Left + dropDownRect.Width / 2,
dropDownRect.Top + dropDownRect.Height / 2);
var arrow = new Point[]
{
new Point(middle.X - 3, middle.Y - 2),
new Point(middle.X + 4, middle.Y - 2),
new Point(middle.X, middle.Y + 2)
};
var borderAndButtonColor = Enabled ? BorderColor : Color.LightGray;
var arrorColor = BackColor;
using (var pen = new Pen(borderAndButtonColor))
g.DrawRectangle(pen, 0, 0,
clientRect.Width - 1, clientRect.Height - 1);
using (var brush = new SolidBrush(borderAndButtonColor))
g.FillRectangle(brush, dropDownRect);
g.FillPolygon(Brushes.Black, arrow);
}
}
}
const int WM_PAINT = 0xF;
const int DTM_FIRST = 0x1000;
const int DTM_GETDATETIMEPICKERINFO = DTM_FIRST + 14;
[DllImport("user32.dll")]
static extern IntPtr SendMessage(IntPtr hWnd, int Msg,
IntPtr wParam, ref DATETIMEPICKERINFO info);
[StructLayout(LayoutKind.Sequential)]
struct RECT
{
public int L, T, R, B;
}
[StructLayout(LayoutKind.Sequential)]
struct DATETIMEPICKERINFO
{
public int cbSize;
public RECT rcCheck;
public int stateCheck;
public RECT rcButton;
public int stateButton;
public IntPtr hwndEdit;
public IntPtr hwndUD;
public IntPtr hwndDropDown;
}
}
Clone or Download Extended version
I have created an extended version of this answer, which supports rendering the up-down button and the checkbox in flat style, also highlighting the arrow on mouse move, something like this:
You can download or close the code:
r-aghaei/FlatDateTimePickerExample
master.zip
Related Posts
You may also want to take a look at the following flat style controls:
Flat TextBox - Change border color of TextBox
Flat ComboBox - Change border color and dropdown button of ComboBox
Flat NumericUpDown - Change border color and spin buttons of NumericUpDown

c# tabControl background color [duplicate]

I have these visual glitches on every tabControls when I am changing its tabPages BackColor and the BackColor of the form, as illustrated on the following images:
At the top of the tabPage, there is an interior one-pixel white border.
At the left of the tabPage, there is an interior three-pixels white border.
At the bottom of the tabPage, there is an interior one-pixel white border and an exterior two-pixels white border.
At the right of the tabPage, there is an interior one-pixel white border and an exterior two-pixels white border.
Is there a way I can get rid of those white borders?

Here's my attempted hack. I used a NativeWindow to draw over the TabControl to fill in those "white" spaces. I won't claim it's perfect:
public class TabPadding : NativeWindow {
private const int WM_PAINT = 0xF;
private TabControl tabControl;
public TabPadding(TabControl tc) {
tabControl = tc;
tabControl.Selected += new TabControlEventHandler(tabControl_Selected);
AssignHandle(tc.Handle);
}
void tabControl_Selected(object sender, TabControlEventArgs e) {
tabControl.Invalidate();
}
protected override void WndProc(ref Message m) {
base.WndProc(ref m);
if (m.Msg == WM_PAINT) {
using (Graphics g = Graphics.FromHwnd(m.HWnd)) {
//Replace the outside white borders:
if (tabControl.Parent != null) {
g.SetClip(new Rectangle(0, 0, tabControl.Width - 2, tabControl.Height - 1), CombineMode.Exclude);
using (SolidBrush sb = new SolidBrush(tabControl.Parent.BackColor))
g.FillRectangle(sb, new Rectangle(0,
tabControl.ItemSize.Height + 2,
tabControl.Width,
tabControl.Height - (tabControl.ItemSize.Height + 2)));
}
//Replace the inside white borders:
if (tabControl.SelectedTab != null) {
g.ResetClip();
Rectangle r = tabControl.SelectedTab.Bounds;
g.SetClip(r, CombineMode.Exclude);
using (SolidBrush sb = new SolidBrush(tabControl.SelectedTab.BackColor))
g.FillRectangle(sb, new Rectangle(r.Left - 3,
r.Top - 1,
r.Width + 4,
r.Height + 3));
}
}
}
}
}
And to hook it up:
public Form1() {
InitializeComponent();
var tab = new TabPadding(tabControl1);
}
My end result:

you can inherit from control
public class TabControlEx : TabControl
{
protected override void WndProc(ref Message m)
{
if (m.Msg == 0x1300 + 40)
{
RECT rc = (RECT)m.GetLParam(typeof(RECT));
rc.Left -= 0;
rc.Right += 3;
rc.Top -= 0;
rc.Bottom += 3;
Marshal.StructureToPtr(rc, m.LParam, true);
}
base.WndProc(ref m);
}
}
internal struct RECT { public int Left, Top, Right, Bottom; }

I recently ran into this problem and never found a good simple solution. That's when I thought about simply adjusting the control's clipping region. This seemed to work just fine with no noticeable side-effects. The 2 extra white pixels on the right side and the one extra white pixel at the bottom are no longer visible.
class TabControlEx : TabControl
{
protected override void WndProc(ref Message m)
{
if (m.Msg == 0x0005) // WM_SIZE
{
int Width = unchecked((short)m.LParam);
int Height = unchecked((short)((uint)m.LParam >> 16));
// Remove the annoying white pixels on the outside of the tab control
// by adjusting the control's clipping region to exclude the 2 pixels
// on the right and one pixel on the bottom.
Region = new Region(new Rectangle(0, 0, Width - 2, Height - 1));
}
base.WndProc(ref m);
}
}

c# RichTextBox Border Color

I'm trying to create a custom RichTextBox with border color, but i have a problem...
My border color not showing
Here's my code :
public partial class AlXRichTextBox : RichTextBox
{
private RichTextBox textBox;
private Color borderColor;
public AlXRichTextBox()
{
InitializeComponent();
}
public Color BorderColor
{
get { return borderColor; }
set { borderColor = value; Invalidate(); }
}
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
Pen p = new Pen(borderColor);
Graphics g = e.Graphics;
int variance = 3;
//g.DrawRectangle(p, new Rectangle(base.Location.X - variance, base.Location.Y - variance, base.Width + variance, base.Height + variance));
ControlPaint.DrawBorder(e.Graphics, base.ClientRectangle, borderColor, ButtonBorderStyle.Solid);
}
private void InitializeComponent()
{
this.textBox = new System.Windows.Forms.RichTextBox();
this.SuspendLayout();
//
// richTextBox1
//
this.textBox.Location = new System.Drawing.Point(0, 0);
this.textBox.Name = "richTextBox1";
this.textBox.Size = new System.Drawing.Size(100, 96);
this.textBox.TabIndex = 0;
this.textBox.Text = "";
this.textBox.Multiline = true;
this.textBox.BorderStyle = BorderStyle.None;
//
// AlXRichTextBox
//
this.Size = new System.Drawing.Size(278, 123);
this.ResumeLayout(false);
}
}
What's problem with this ?

Referring to MSDN article :
Overriding OnPaint will not allow you to modify the appearance of all controls. Those controls that have all of their painting done by Windows (for example, TextBox) never call their OnPaint method, and thus will never use the custom code. Refer to the Help documentation for the particular control you want to modify to see if the OnPaint method is available. For a list of all the Windows Form Controls, see Controls to Use on Windows Forms. If a control does not have OnPaint listed as a member method, you cannot alter its appearance by overriding this method. For more information about custom painting, see Custom Control Painting and Rendering.
However there is a "hack", You can achieve calling the Paint method by calling following code:
private const int WM_PAINT = 15;
protected override void WndProc(ref System.Windows.Forms.Message m)
{
base.WndProc(ref m);
if (m.Msg == WM_PAINT && !inhibitPaint)
{
// raise the paint event
using (Graphics graphic = base.CreateGraphics())
OnPaint(new PaintEventArgs(graphic,
base.ClientRectangle));
}
}
private bool inhibitPaint = false;
public bool InhibitPaint
{
set { inhibitPaint = value; }
}
Src: RichTextBox and UserPaint
Other point is that You cannot draw outside of the Rectangle (which is total size of Your RichTB component. So You actually want to provide him with different Coords (smaller inner ones) and You will draw to the outside.
Your class will look like:
public partial class AlXRichTextBox : RichTextBox
{
private Color borderColor = Color.Red;
public Color BorderColor
{
get { return borderColor; }
set { borderColor = value; Invalidate(); }
}
protected override void OnPaint(PaintEventArgs e)
{
int variance = 3;
e = new PaintEventArgs(e.Graphics, new Rectangle(e.ClipRectangle.X + variance, e.ClipRectangle.Y + variance, e.ClipRectangle.Width - variance, e.ClipRectangle.Height - variance));
base.OnPaint(e);
Pen p = new Pen(borderColor, variance);
Graphics g = e.Graphics;
g.DrawRectangle(p, new Rectangle(e.ClipRectangle.X, e.ClipRectangle.Y, e.ClipRectangle.Width, e.ClipRectangle.Height));
}
private const int WM_PAINT = 15;
protected override void WndProc(ref System.Windows.Forms.Message m)
{
base.WndProc(ref m);
if (m.Msg == WM_PAINT && !inhibitPaint)
{
// raise the paint event
using (Graphics graphic = base.CreateGraphics())
OnPaint(new PaintEventArgs(graphic,
base.ClientRectangle));
}
}
private bool inhibitPaint = false;
public bool InhibitPaint
{
set { inhibitPaint = value; }
}
}
IMPORTANT
As it is not expected for this control to be changed by Paint, You will get "not nice" behavior in regards to the drawing changes like border, new elements etc.. If You would like to use such element, consider using WPF - Windows Presentation Foundation. They are much more nicer to templating the items and modifying design.

A little late answer, but I was on same path as you these days and It got me to this solution, It works for me:
using System;
using System.Drawing;
using System.Windows.Forms;
public class MyRichTextBox : RichTextBox
{
private const UInt32 WM_PAINT = 0x000F;
private const UInt32 WM_USER = 0x0400;
private const UInt32 EM_SETBKGNDCOLOR = (WM_USER + 67);
private const UInt32 WM_KILLFOCUS = 0x0008;
public MyRichTextBox()
{
this.BorderStyle = System.Windows.Forms.BorderStyle.None;
}
protected override void WndProc(ref System.Windows.Forms.Message m)
{
base.WndProc(ref m);
Graphics g = Graphics.FromHwnd(Handle);
Rectangle bounds = new Rectangle(0, 0, Width - 1, Height - 1);
Pen p = new Pen(SystemColors.Highlight, 3);
if (m.Msg == WM_PAINT)
{
if (this.Enabled == true)
{
if (this.Focused)
{
g.DrawRectangle(p, bounds);
}
else
{
g.DrawRectangle(SystemPens.ControlDark, bounds);
}
}
else
{
g.FillRectangle(Brushes.White, bounds);
g.DrawRectangle(SystemPens.Control, bounds);
}
}
if (m.Msg == EM_SETBKGNDCOLOR) //color disabled background
{
Invalidate();
}
if (m.Msg == WM_KILLFOCUS) //set border back to normal on lost focus
{
Invalidate();
}
}
}
This Rich Textbox changes 3 border colors - enabled, focused and disabled with disabled background. As you see the code is simple and short. The only trick is to overide KILL_FOCUS and EM_SETBKGNDCOLOR messages (this one is for changing disabled background), and RichTextbox should be BorderStyle=None. Cheers !

Textbox custom onPaint

I'm trying to create a custom onPaint for my textbox, it is working... it is working But when I try to type something, a textbox is rendering above the textbox.
This is my constructor:
public TextBox()
{
Font = new Font("Segoe UI", 11F, FontStyle.Regular, GraphicsUnit.Point, ((byte)(0)));
BackColor = Color.White;
BorderColor = Color.Gray;
BorderStyle = BorderStyle.None;
SetStyle(ControlStyles.UserPaint, true);
}
And the onPaint:
protected override void OnPaint(PaintEventArgs e)
{
Graphics g = e.Graphics;
g.FillRectangle(backgroundBrush, 0, 0, this.Width, this.Height);
SizeF fontSize = g.MeasureString(Text, Font);
g.DrawString(Text, Font, new SolidBrush(ForeColor), new PointF(5, 5), cFormat);
g.DrawRectangle(borderPen, borderPen.Width / 2, borderPen.Width / 2,
this.Width - borderPen.Width, this.Height - borderPen.Width);
}

If you just want a custom TextBox with some custom border (width and color), I have 2 solutions here:
Using ControlPaint, this will allow you to draw border with some style and color but can't use Brush to draw more variously (like a HatchBrush can do):
public class CustomTextBox : TextBox
{
[DllImport("user32")]
private static extern IntPtr GetWindowDC(IntPtr hwnd);
struct RECT
{
public int left, top, right, bottom;
}
struct NCCALSIZE_PARAMS
{
public RECT newWindow;
public RECT oldWindow;
public RECT clientWindow;
IntPtr windowPos;
}
float clientPadding = 2;
float actualBorderWidth = 4;
Color borderColor = Color.Red;
protected override void WndProc(ref Message m)
{
//We have to change the clientsize to make room for borders
//if not, the border is limited in how thick it is.
if (m.Msg == 0x83) //WM_NCCALCSIZE
{
if (m.WParam == IntPtr.Zero)
{
RECT rect = (RECT)Marshal.PtrToStructure(m.LParam, typeof(RECT));
rect.left += clientPadding;
rect.right -= clientPadding;
rect.top += clientPadding;
rect.bottom -= clientPadding;
Marshal.StructureToPtr(rect, m.LParam, false);
}
else
{
NCCALSIZE_PARAMS rects = (NCCALSIZE_PARAMS)Marshal.PtrToStructure(m.LParam, typeof(NCCALSIZE_PARAMS));
rects.newWindow.left += clientPadding;
rects.newWindow.right -= clientPadding;
rects.newWindow.top += clientPadding;
rects.newWindow.bottom -= clientPadding;
Marshal.StructureToPtr(rects, m.LParam, false);
}
}
if (m.Msg == 0x85) //WM_NCPAINT
{
IntPtr wDC = GetWindowDC(Handle);
using(Graphics g = Graphics.FromHdc(wDC)){
ControlPaint.DrawBorder(g, new Rectangle(0,0,Size.Width, Size.Height), borderColor, actualBorderWidth, ButtonBorderStyle.Solid,
borderColor, actualBorderWidth, ButtonBorderStyle.Solid, borderColor, actualBorderWidth, ButtonBorderStyle.Solid,
borderColor, actualBorderWidth, ButtonBorderStyle.Solid);
}
return;
}
base.WndProc(ref m);
}
}
Here is the textbox snapshot:
using FillRegion method of a Graphics to paint the border with various kinds of Brush, here I use HatchBrush:
public class CustomTextBox : TextBox
{
[DllImport("user32")]
private static extern IntPtr GetWindowDC(IntPtr hwnd);
struct RECT
{
public int left, top, right, bottom;
}
struct NCCALSIZE_PARAMS
{
public RECT newWindow;
public RECT oldWindow;
public RECT clientWindow;
IntPtr windowPos;
}
int clientPadding = 2;
int actualBorderWidth = 4;
protected override void WndProc(ref Message m)
{
//We have to change the clientsize to make room for borders
//if not, the border is limited in how thick it is.
if (m.Msg == 0x83) //WM_NCCALCSIZE
{
if (m.WParam == IntPtr.Zero)
{
RECT rect = (RECT)Marshal.PtrToStructure(m.LParam, typeof(RECT));
rect.left += clientPadding;
rect.right -= clientPadding;
rect.top += clientPadding;
rect.bottom -= clientPadding;
Marshal.StructureToPtr(rect, m.LParam, false);
}
else
{
NCCALSIZE_PARAMS rects = (NCCALSIZE_PARAMS)Marshal.PtrToStructure(m.LParam, typeof(NCCALSIZE_PARAMS));
rects.newWindow.left += clientPadding;
rects.newWindow.right -= clientPadding;
rects.newWindow.top += clientPadding;
rects.newWindow.bottom -= clientPadding;
Marshal.StructureToPtr(rects, m.LParam, false);
}
}
if (m.Msg == 0x85) //WM_NCPAINT
{
IntPtr wDC = GetWindowDC(Handle);
using(Graphics g = Graphics.FromHdc(wDC)){
Rectangle rect = new Rectangle(0,0,Width,Height);
Rectangle inner = new Rectangle(0, 0, Width, Height);
inner.Offset(actualBorderWidth + 2, actualBorderWidth + 2);
inner.Width -= 2 * actualBorderWidth + 4;
inner.Height -= 2 * actualBorderWidth + 4;
Region r = new Region(rect);
r.Xor(inner);
using (System.Drawing.Drawing2D.HatchBrush brush = new System.Drawing.Drawing2D.HatchBrush(System.Drawing.Drawing2D.HatchStyle.SmallCheckerBoard, Color.Green, Color.Red))
{
g.FillRegion(brush, r);
}
}
return;
}
base.WndProc(ref m);
}
}
Here is the textbox snapshot:

Fading control in C#

I'm tring to build a Control derived class which supports an Opcacity property.
This control could host both text and image and will beable to fade them out and in.
Here is my code:
internal class FadeControl : Control
{
private int opacity = 100;
public FadeControl()
{
SetStyle(ControlStyles.SupportsTransparentBackColor, true);
}
public int Opacity
{
get
{
return opacity;
}
set
{
if (value > 100) opacity = 100;
else if (value < 1) opacity = 1;
else opacity = value;
if (Parent != null)
Parent.Invalidate(Bounds, true);
}
}
protected override CreateParams CreateParams
{
get
{
CreateParams cp = base.CreateParams;
cp.ExStyle = cp.ExStyle | 0x20;
return cp;
}
}
protected override void OnPaintBackground(PaintEventArgs e)
{
//do nothing
}
protected override void OnMove(EventArgs e)
{
RecreateHandle();
}
protected override void OnPaint(PaintEventArgs e)
{
using (Graphics g = e.Graphics)
{
Rectangle bounds = new Rectangle(0, 0, Width - 1, Height - 1);
int alpha = (opacity * 255) / 100;
using (Brush bckColor = new SolidBrush(Color.FromArgb(alpha, BackColor)))
{
if (BackColor != Color.Transparent)
g.FillRectangle(bckColor, bounds);
}
ColorMatrix colorMatrix = new ColorMatrix();
colorMatrix.Matrix33 = (float)alpha / 255;
ImageAttributes imageAttr = new ImageAttributes();
imageAttr.SetColorMatrix(colorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
if (BackgroundImage != null)
g.DrawImage(BackgroundImage, bounds, 0, 0, Width, Height, GraphicsUnit.Pixel, imageAttr);
if (Text != string.Empty)
{
using (Brush txtBrush = new SolidBrush(Color.FromArgb(alpha, ForeColor)))
{
g.DrawString(Text, Font, txtBrush, 5, 5);
}
}
}
}
protected override void OnBackColorChanged(EventArgs e)
{
if (Parent != null)
Parent.Invalidate(Bounds, true);
base.OnBackColorChanged(e);
}
protected override void OnParentBackColorChanged(EventArgs e)
{
Invalidate();
base.OnParentBackColorChanged(e);
}
}
I've putted the control on a form which has a timer on it.
The timer set the control's opacity from 0 to 100 and back and its working well.
The problem I'm trying to solved is that the control flickers while changing its opacity.
Setting the control toControlStyles.DoubleBuffer will make the control invisible on the form.
Any advice will be welcome.

I was unable to use both a double buffer and WS_EX_TRANSPARENT (0x20) for the transparent background. So I decided to implement the transparent background by copying the content of the parent control and use double buffer to prevent flicker.
The following is the final source code, tested and working:
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;
internal class FadeControl : Control
{
private int opacity = 100;
private Bitmap backgroundBuffer;
private bool skipPaint;
public FadeControl()
{
SetStyle(ControlStyles.SupportsTransparentBackColor, true);
SetStyle(ControlStyles.ResizeRedraw, true);
SetStyle(ControlStyles.DoubleBuffer |
ControlStyles.AllPaintingInWmPaint |
ControlStyles.UserPaint, true);
}
public int Opacity
{
get
{
return opacity;
}
set
{
if (value > 100) opacity = 100;
else if (value < 1) opacity = 1;
else opacity = value;
if (Parent != null)
Parent.Invalidate(Bounds, true);
}
}
protected override void OnPaintBackground(PaintEventArgs e)
{
//do nothig
}
protected override void OnMove(EventArgs e)
{
RecreateHandle();
}
private void CreateBackgroundBuffer(Control parent)
{
int offsetX;
int offsetY;
GetOffsets(out offsetX, out offsetY, parent);
backgroundBuffer = new Bitmap(Width + offsetX, Height + offsetY);
}
protected override void OnResize(EventArgs e)
{
var parent = Parent;
if (parent != null)
{
CreateBackgroundBuffer(parent);
}
base.OnResize(e);
}
private void GetOffsets(out int offsetX, out int offsetY, Control parent)
{
var parentPosition = parent.PointToScreen(Point.Empty);
offsetY = Top + parentPosition.Y - parent.Top;
offsetX = Left + parentPosition.X - parent.Left;
}
private void UpdateBackgroundBuffer(int offsetX, int offsetY, Control parent)
{
if (backgroundBuffer == null)
{
CreateBackgroundBuffer(parent);
}
Rectangle parentBounds = new Rectangle(0, 0, Width + offsetX, Height + offsetY);
skipPaint = true;
parent.DrawToBitmap(backgroundBuffer, parentBounds);
skipPaint = false;
}
private void DrawBackground(Graphics graphics, Rectangle bounds)
{
int offsetX;
int offsetY;
var parent = Parent;
GetOffsets(out offsetX, out offsetY, parent);
UpdateBackgroundBuffer(offsetX, offsetY, parent);
graphics.DrawImage(backgroundBuffer, bounds, offsetX, offsetY, Width, Height, GraphicsUnit.Pixel);
}
private void Draw(Graphics graphics)
{
Rectangle bounds = new Rectangle(0, 0, Width, Height);
DrawBackground(graphics, bounds);
int alpha = (opacity * 255) / 100;
using (Brush bckColor = new SolidBrush(Color.FromArgb(alpha, BackColor)))
{
if (BackColor != Color.Transparent)
{
graphics.FillRectangle(bckColor, bounds);
}
}
ColorMatrix colorMatrix = new ColorMatrix();
colorMatrix.Matrix33 = (float)alpha / 255;
ImageAttributes imageAttr = new ImageAttributes();
imageAttr.SetColorMatrix(colorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
if (BackgroundImage != null)
{
graphics.DrawImage(BackgroundImage, bounds, 0, 0, Width, Height, GraphicsUnit.Pixel, imageAttr);
}
if (Text != string.Empty)
{
using (Brush txtBrush = new SolidBrush(Color.FromArgb(alpha, ForeColor)))
{
graphics.DrawString(Text, Font, txtBrush, 5, 5);
}
}
}
protected override void OnPaint(PaintEventArgs e)
{
if (!skipPaint)
{
Graphics graphics = e.Graphics;
Draw(graphics);
}
}
protected override void OnBackColorChanged(EventArgs e)
{
if (Parent != null)
{
Parent.Invalidate(Bounds, true);
}
base.OnBackColorChanged(e);
}
protected override void OnParentBackColorChanged(EventArgs e)
{
Invalidate();
base.OnParentBackColorChanged(e);
}
}
Note that the method CreateParams is no longer present, also I've changed the contructor.
The field skipPaint is to know when not to paint in order to be able to able to tell the parent to draw itself to a bitmap during OnPaint without having infinite recursion.
backgroundBuffer is not to implement double buffering, but to keep a copy of the contents of the parent without the control rendered. It is updated each paint, I know there are more efficient solutions...* yet this approach keeps it simple and shouldn't be a bottleneck unless you have too many of these controls on the same container.
*: A better solution would be to update it each time the parent invalidates. Futhermore shared it among all the FadeControls in the same parent.