Click here to Skip to main content
11,633,476 members (76,088 online)
Click here to Skip to main content

Aqua Gauge

, 4 Sep 2007 CPOL 283.8K 24.6K 354
Rate this:
Please Sign up or sign in to vote.
A Gauge Control Developed using GDI+ with Aqua Skin
Screenshot - AquaGauge.gif

Introduction

I have chosen to develop this .NET user control to explore the easy yet powerful .NET GDI+. This simple gauge control developed using .NET 2.0 can cater to the entire range of monitoring purposes. Let's see how to develop such a glossy control using GDI+.

Overridden UserControl Methods

Normally, If we create user controls that have been fully drawn by the user, we should override the OnPaint and OnPaintBackground methods. Additionally, the control styles are to be set as appropriate. The following common styles can be set using this.SetStyle(ControlStyles.XXXXX, true/false);.

SupportsTransparentBackColor This will enable your control to support a transparent backcolor if set to true.
ControlStyles.ResizeRedraw Allows repainting when the control is resized.
ControlStyles.AllPaintingInWmPaint If true, the control ignores the window message WM_ERASEBKGND to reduce flicker.
This style should only be applied if the UserPaint bit is set to true.
ControlStyles.UserPaint If true, the control paints itself rather than the operating system doing so.
ControlStyles.OptimizedDoubleBuffer If true, the control is first drawn to a buffer rather than directly to the screen, which can reduce flicker. If you set this property to true, you should also set the AllPaintingInWmPaint to true.

The OnPaint and OnPaintBackground methods will be called whenever the control needs to be repainted. For example, when the control is resized or the form is minimized and maximized, the OnPaint method will be called.

OnPaintBackground vs. OnPaint

OnPaintBackground paints the background (and thereby the shape) of the Window and is guaranteed to be fast. In contrast, OnPaint paints the details and might be slower because individual paint requests are combined into one Paint event that covers all areas that have to be redrawn. You might want to invoke the OnPaintBackground if, for instance, you want to draw a gradient-colored background for your control.

While OnPaintBackground has an event-like nomenclature and takes the same argument as the OnPaint method, OnPaintBackground is not a true event method. There is no PaintBackground event and OnPaintBackground does not invoke event delegates. When overriding the OnPaintBackground method, a derived class is not required to invoke the OnPaintBackground method of its base class.

Drawing the Guage Dial

First, let's see how to draw the dial. The dial requires a Scale, Threshold Indicator, some text and the current value to be displayed.

Drawing the scale requires calculating the positions for the rules that are to be drawn at the circumference. Let's say we need to draw a scale starting from 0 to 10 from angle 90 degrees to 270 degrees on the dial. In this case, the difference in the degrees (270-90 = 180) must be divided into 10 parts. To find the position for each part to be drawn, we need the following formula:

x = centerX + radius * cos(180/partNo)
y = centerY + radius * sin(180/partNo)

Note: when using Math.Cos or Math.Sin we should give angles in radians.

Circle Formula

After finding the position, we can draw any type of scale mark on the circumference. I have chosen to draw a line as a scale mark. Since the dial area is not going to be changed often, it can be drawn in OnPaintBackground overridden method.

Drawing the Pointer

The pointer may need to be repainted often. So, it is better to draw it in the OnPaint method. Finding the pointer position is the same as the logic for drawing the scale. The pointer can be drawn using graphicsObj.FillPolygon() method and it can be transformed to any angle that will represent the current value. Otherwise, the pointer can be redrawn for every change made for the current value.

Drawing the Glossiness

Drawing the glossiness is very simple. All you have to do is, after painting all the dial and pointer, fill two ellipses with gradient coloring. The LinearGradientBrush class provides the ability to draw gradient fills. Masking the gradient layer over the dial gives the glossiness as shown in the below figure.

Glosiness

Using the AquaGauge Control

This AquaGauge control can be used as any other user control provided by Windows. The following are the control-specific properties that can be used to configure this gauge to suit your requirements.

Property Name Type Description
DialColor Color Gets or Sets the background color for the gauge.
DialText String Gets or Sets the Text displayed on the gauge dial.
EnableTransparentBackground bool Enables or Disables Transparent Background color. Note: Enabling this will reduce the performance and may make the control flicker.
Glossiness float Gets or Sets the strength of the Glossiness.
MaxValue float Gets or Sets the maximum value shown on the gauge scale.
MinValue float Gets or Sets the minimum value shown on the gauge scale.
NoOfDivisions int Gets or Sets the number of divisions on the gauge scale.
NoOfSubDivisions int Gets or Sets the number of subdivisions displayed on the scale for each division.
RecommendedValue float Gets or Sets the recommended value on the scale. This will be used as a pivot point for drawing the threshold area.
ThresholdPercent float Gets or Sets the Threshold area percentage on the scale.
Value float Gets or Sets the value to which the pointer will point.

Points of Interest

Whenever we draw images with lots of manipulations, it is recommended to draw it on an image object and then paint. For example, drawing the gauge dial requires lots of CPU-consuming operations. So, we can draw the dial onto an image and then draw using graphicsObj.DrawImage(). Whenever changes are made on the dial properties, we can recreate the image object. It would improve the performance.

History

  • Version 1.0 - Initial Version

All comments and suggestions are welcome.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Share

About the Author

Ambalavanar Thirugnanam
Architect BNY Mellon
India India
Ambalavanar, working as a .NET Solutions Architect at BNY Mellon (iNautix), Chennai. Enjoys designing and developing UI & highly scalable apps.

You may also be interested in...

Comments and Discussions

 
GeneralVery Nice Pin
JJMatthews4-Dec-08 15:46
memberJJMatthews4-Dec-08 15:46 
GeneralThanks! Pin
Colores214-Nov-08 18:33
memberColores214-Nov-08 18:33 
GeneralDial Text Pin
ashesman12-Oct-08 20:41
memberashesman12-Oct-08 20:41 
GeneralRe: Dial Text Pin
Ambalavanar Thirugnanam17-Oct-08 2:44
memberAmbalavanar Thirugnanam17-Oct-08 2:44 
QuestionHow can I use this control in other language? Pin
jeffri1516-Sep-08 14:29
memberjeffri1516-Sep-08 14:29 
GeneralGood and Useful Pin
Angelo Cresta19-Jun-08 2:53
memberAngelo Cresta19-Jun-08 2:53 
GeneralRe: Good and Useful Pin
Ambalavanar Thirugnanam19-Jun-08 17:19
memberAmbalavanar Thirugnanam19-Jun-08 17:19 
GeneralAwesome [modified] Pin
ErnestMoore2-May-08 4:57
memberErnestMoore2-May-08 4:57 
GeneralRe: Awesome Pin
Angelo Cresta18-Jun-08 5:32
memberAngelo Cresta18-Jun-08 5:32 
GeneralVery Nice Very Professional looking Pin
lokiblack18-Apr-08 12:32
memberlokiblack18-Apr-08 12:32 
GeneralRe: Very Nice Very Professional looking Pin
Ambalavanar Thirugnanam18-Apr-08 20:14
memberAmbalavanar Thirugnanam18-Apr-08 20:14 
QuestionCan we used this control in ASP.Net 2.0? Pin
Nikhil_pune13-Mar-08 21:41
memberNikhil_pune13-Mar-08 21:41 
GeneralLove this control Pin
pduffin29-Nov-07 8:45
memberpduffin29-Nov-07 8:45 
GeneralRe: Love this control Pin
Ambalavanar Thirugnanam17-Dec-07 2:58
memberAmbalavanar Thirugnanam17-Dec-07 2:58 
Thanks for the comment. Smile | :)
-----------------------------
Go far with your knowledge...
Further with google...

Generaldemo project request Pin
cncbashing16-Nov-07 13:33
membercncbashing16-Nov-07 13:33 
GeneralRe: demo project request Pin
Bob10005-May-08 2:34
memberBob10005-May-08 2:34 
Generalsmooth movement Pin
oneteam12-Nov-07 0:59
memberoneteam12-Nov-07 0:59 
GeneralThis control flickers when used with other gdi paints Pin
Stig_Brannlund26-Oct-07 11:26
memberStig_Brannlund26-Oct-07 11:26 
GeneralVery nice Pin
victorbos18-Oct-07 4:26
membervictorbos18-Oct-07 4:26 
GeneralSuggested adaption / Alpha Transparency Pin
pthomet30-Sep-07 6:56
memberpthomet30-Sep-07 6:56 
GeneralMast hai ! It's Great ! Pin
pthomet30-Sep-07 6:24
memberpthomet30-Sep-07 6:24 
GeneralRe: Mast hai ! It's Great ! Pin
Ambalavanar Thirugnanam30-May-08 7:04
memberAmbalavanar Thirugnanam30-May-08 7:04 
QuestionHow to run?? Pin
sanjayeinstein17-Sep-07 11:16
membersanjayeinstein17-Sep-07 11:16 
AnswerRe: How to run?? Pin
Ambalavanar Thirugnanam19-Sep-07 18:31
memberAmbalavanar Thirugnanam19-Sep-07 18:31 
GeneralDisposing of resources Pin
Keith Iveson14-Sep-07 1:45
memberKeith Iveson14-Sep-07 1:45 
GeneralRe: Disposing of resources Pin
vkolgi9-Sep-08 0:16
membervkolgi9-Sep-08 0:16 
GeneralRe: Disposing of resources Pin
Keith Iveson9-Sep-08 2:12
memberKeith Iveson9-Sep-08 2:12 
QuestionDigital display Pin
Bruce McKinnon12-Sep-07 12:16
memberBruce McKinnon12-Sep-07 12:16 
AnswerRe: Digital display [modified] Pin
JF201513-Sep-07 17:57
memberJF201513-Sep-07 17:57 
GeneralRe: Digital display Pin
Bruce McKinnon13-Sep-07 19:17
memberBruce McKinnon13-Sep-07 19:17 
GeneralProblems Pin
JF201510-Sep-07 19:55
memberJF201510-Sep-07 19:55 
GeneralRe: Problems Pin
Joe Sonderegger10-Sep-07 22:35
memberJoe Sonderegger10-Sep-07 22:35 
GeneralRe: Problems Pin
three1111-Sep-07 15:09
memberthree1111-Sep-07 15:09 
GeneralRe: Problems Pin
JF201511-Sep-07 18:01
memberJF201511-Sep-07 18:01 
GeneralRe: Problems Pin
William Ten Broek13-Sep-07 5:18
memberWilliam Ten Broek13-Sep-07 5:18 
GeneralRe: Problems / Solution to label refresh issue Pin
pthomet30-Sep-07 15:08
memberpthomet30-Sep-07 15:08 
GeneralCoooooooooooooooooooooool maaaaaaaaaaaaan! Pin
Muammar©10-Sep-07 19:45
memberMuammar©10-Sep-07 19:45 
GeneralVB Translation Pin
BobishKindaGuy10-Sep-07 17:52
memberBobishKindaGuy10-Sep-07 17:52 
GeneralRe: VB Translation Pin
Devious26-Feb-08 19:53
memberDevious26-Feb-08 19:53 
GeneralRe: VB Translation Pin
Scorpio12-Feb-09 4:47
memberScorpio12-Feb-09 4:47 
GeneralExcellent reusable component Pin
GanesanSenthilvel5-Sep-07 5:45
memberGanesanSenthilvel5-Sep-07 5:45 
GeneralAwesome Control Pin
SurenSoman5-Sep-07 4:43
memberSurenSoman5-Sep-07 4:43 
GeneralLooks great Pin
Jonathan [Darka]4-Sep-07 22:31
memberJonathan [Darka]4-Sep-07 22:31 
QuestionDemo Project Pin
thomasswilliams4-Sep-07 17:21
memberthomasswilliams4-Sep-07 17:21 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

| Advertise | Privacy | Terms of Use | Mobile
Web04 | 2.8.150728.1 | Last Updated 4 Sep 2007
Article Copyright 2007 by Ambalavanar Thirugnanam
Everything else Copyright © CodeProject, 1999-2015
Layout: fixed | fluid