|
|
You're in the
dotnet windows forms designtime
group:Error on LinearGradientBrush
dotnet windows forms designtime:
This is a known error (at least known to me) with LinearGradientBrush. It
seems that the colour gradient is calculated slightly too short. The work-around is to make the gradient 1 pixel larger than the destination drawing rectangle. -- Bob Powell [MVP] Visual C#, System.Drawing Ramuseco Limited .NET consulting http://www.ramuseco.com Find great Windows Forms articles in Windows Forms Tips and Tricks http://www.bobpowell.net/tipstricks.htm Answer those GDI+ questions with the GDI+ FAQ http://www.bobpowell.net/faqmain.htm All new articles provide code in C# and VB.NET. Subscribe to the RSS feeds provided and never miss a new article. [quoted text, click to view] "Carlo" <Carlo@discussions.microsoft.com> wrote in message news:2D471195-83E4-4C85-BE52-602F7512ACCE@microsoft.com... > Hello > > I found an abnormal behaviour on LinearGradientBrush (or FillRectangle). > This code > > Public Class PanelPanel > Inherits System.Windows.Forms.Panel > Protected Overrides Sub OnPaint(ByVal e As > System.Windows.Forms.PaintEventArgs) > Dim rect As System.Drawing.Rectangle = New > System.Drawing.Rectangle(10, 10, Me.Width - 20, Me.Height - 20) > Dim gradientBrush As System.Drawing.Drawing2D.LinearGradientBrush > gradientBrush = New > System.Drawing.Drawing2D.LinearGradientBrush(rect, _ > System.Drawing.Color.Gray, _ > > System.Drawing.Color.FloralWhite, _ > > System.Drawing.Drawing2D.LinearGradientMode.Vertical) > e.Graphics.FillRectangle(gradientBrush, rect) > End Sub > End Class > > generates a control with an rectangle drawn inside. > The problem is that an unusual line (colored Color.FloralWhite) appears on > the top edge of the rectangle. This line should not be there. > If LinearGradientMode id other than Vertical the problem persists, but it > is > less visible (only a small colored pixel is visible). > > Please note that the anomaly appears only with some rectangle sizes. > Example: > if rect={X=10,Y=10,Width=304,Height=208} 'equivalent to a Me.Size=New > Size(324,228) - Anomaly visible > if rect={X=10,Y=10,Width=304,Height=216} 'Correct, anomaly not visible > > Could someone PLEASE try to reproduce the problem (just copy code as is) > and > confirm that is an error and then reason with me?? > > Thank you!. > > Carlo > > (MCP) > >
Hello Bob
I'm very glad to meet you on the ng. I recently used your page named "The ToolboxBitmap puzzle"! Thank you for the suggestion. Applying your suggestion means that I'll get rectangles that overflows my needs by 1 pixel. Unfortunately, this is unacceptable for my needs since I calculate rectangles sizes based on MeasureString for a very accurate placement of text(s) and image(s) on the control. Thank you for replying Carlo "Bob Powell [MVP]" <bob@_spamkiller_bobpowell.net> ha scritto nel messaggio news:%2322vS30xFHA.1284@tk2msftngp13.phx.gbl... [quoted text, click to view] > This is a known error (at least known to me) with LinearGradientBrush. It seems that the colour gradient is calculated > slightly too short. The work-around is to make the gradient 1 pixel larger than the destination drawing rectangle. > > -- > Bob Powell [MVP] > Visual C#, System.Drawing > > Ramuseco Limited .NET consulting > http://www.ramuseco.com > > Find great Windows Forms articles in Windows Forms Tips and Tricks > http://www.bobpowell.net/tipstricks.htm > > Answer those GDI+ questions with the GDI+ FAQ > http://www.bobpowell.net/faqmain.htm > > All new articles provide code in C# and VB.NET. > Subscribe to the RSS feeds provided and never miss a new article. > > > > > > "Carlo" <Carlo@discussions.microsoft.com> wrote in message news:2D471195-83E4-4C85-BE52-602F7512ACCE@microsoft.com... >> Hello >> >> I found an abnormal behaviour on LinearGradientBrush (or FillRectangle). >> This code >> >> Public Class PanelPanel >> Inherits System.Windows.Forms.Panel >> Protected Overrides Sub OnPaint(ByVal e As >> System.Windows.Forms.PaintEventArgs) >> Dim rect As System.Drawing.Rectangle = New >> System.Drawing.Rectangle(10, 10, Me.Width - 20, Me.Height - 20) >> Dim gradientBrush As System.Drawing.Drawing2D.LinearGradientBrush >> gradientBrush = New System.Drawing.Drawing2D.LinearGradientBrush(rect, _ >> System.Drawing.Color.Gray, _ >> >> System.Drawing.Color.FloralWhite, _ >> >> System.Drawing.Drawing2D.LinearGradientMode.Vertical) >> e.Graphics.FillRectangle(gradientBrush, rect) >> End Sub >> End Class >> >> generates a control with an rectangle drawn inside. >> The problem is that an unusual line (colored Color.FloralWhite) appears on >> the top edge of the rectangle. This line should not be there. >> If LinearGradientMode id other than Vertical the problem persists, but it is >> less visible (only a small colored pixel is visible). >> >> Please note that the anomaly appears only with some rectangle sizes. Example: >> if rect={X=10,Y=10,Width=304,Height=208} 'equivalent to a Me.Size=New >> Size(324,228) - Anomaly visible >> if rect={X=10,Y=10,Width=304,Height=216} 'Correct, anomaly not visible >> >> Could someone PLEASE try to reproduce the problem (just copy code as is) and >> confirm that is an error and then reason with me?? >> >> Thank you!. >> >> Carlo >> >> (MCP) >> >> > >
Hello
I found an abnormal behaviour on LinearGradientBrush (or FillRectangle). This code Public Class PanelPanel Inherits System.Windows.Forms.Panel Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs) Dim rect As System.Drawing.Rectangle = New System.Drawing.Rectangle(10, 10, Me.Width - 20, Me.Height - 20) Dim gradientBrush As System.Drawing.Drawing2D.LinearGradientBrush gradientBrush = New System.Drawing.Drawing2D.LinearGradientBrush(rect, _ System.Drawing.Color.Gray, _ System.Drawing.Color.FloralWhite, _ System.Drawing.Drawing2D.LinearGradientMode.Vertical) e.Graphics.FillRectangle(gradientBrush, rect) End Sub End Class generates a control with an rectangle drawn inside. The problem is that an unusual line (colored Color.FloralWhite) appears on the top edge of the rectangle. This line should not be there. If LinearGradientMode id other than Vertical the problem persists, but it is less visible (only a small colored pixel is visible). Please note that the anomaly appears only with some rectangle sizes. Example: if rect={X=10,Y=10,Width=304,Height=208} 'equivalent to a Me.Size=New Size(324,228) - Anomaly visible if rect={X=10,Y=10,Width=304,Height=216} 'Correct, anomaly not visible Could someone PLEASE try to reproduce the problem (just copy code as is) and confirm that is an error and then reason with me?? Thank you!. Carlo (MCP)
A good alternative too...
-- Bob Powell [MVP] Visual C#, System.Drawing Ramuseco Limited .NET consulting http://www.ramuseco.com Find great Windows Forms articles in Windows Forms Tips and Tricks http://www.bobpowell.net/tipstricks.htm Answer those GDI+ questions with the GDI+ FAQ http://www.bobpowell.net/faqmain.htm All new articles provide code in C# and VB.NET. Subscribe to the RSS feeds provided and never miss a new article. [quoted text, click to view] "Frank Hileman" <frankhil@no.spamming.prodigesoftware.com> wrote in message news:%23mRE64CyFHA.624@TK2MSFTNGP11.phx.gbl... > Change the WrapMode to TileFlipXY. > > Regards, > Frank Hileman > > check out VG.net: http://www.vgdotnet.com > Animated vector graphics system > Integrated Visual Studio .NET graphics editor > > "Carlo, MCP" <carlodevREMOVE@gmail.com> wrote in message > news:OHcaTG1xFHA.3588@tk2msftngp13.phx.gbl... >> Hello Bob >> I'm very glad to meet you on the ng. I recently used your page named "The >> ToolboxBitmap puzzle"! >> >> Thank you for the suggestion. Applying your suggestion means that I'll >> get rectangles that overflows my needs by 1 pixel. >> Unfortunately, this is unacceptable for my needs since I calculate >> rectangles sizes based on MeasureString for a very accurate placement of >> text(s) and image(s) on the control. >> Thank you for replying >> >> Carlo >> >> >> >> "Bob Powell [MVP]" <bob@_spamkiller_bobpowell.net> ha scritto nel >> messaggio news:%2322vS30xFHA.1284@tk2msftngp13.phx.gbl... >>> This is a known error (at least known to me) with LinearGradientBrush. >>> It seems that the colour gradient is calculated slightly too short. The >>> work-around is to make the gradient 1 pixel larger than the destination >>> drawing rectangle. >>> >>> -- >>> Bob Powell [MVP] >>> Visual C#, System.Drawing >>> >>> Ramuseco Limited .NET consulting >>> http://www.ramuseco.com >>> >>> Find great Windows Forms articles in Windows Forms Tips and Tricks >>> http://www.bobpowell.net/tipstricks.htm >>> >>> Answer those GDI+ questions with the GDI+ FAQ >>> http://www.bobpowell.net/faqmain.htm >>> >>> All new articles provide code in C# and VB.NET. >>> Subscribe to the RSS feeds provided and never miss a new article. >>> >>> >>> >>> >>> >>> "Carlo" <Carlo@discussions.microsoft.com> wrote in message >>> news:2D471195-83E4-4C85-BE52-602F7512ACCE@microsoft.com... >>>> Hello >>>> >>>> I found an abnormal behaviour on LinearGradientBrush (or >>>> FillRectangle). >>>> This code >>>> >>>> Public Class PanelPanel >>>> Inherits System.Windows.Forms.Panel >>>> Protected Overrides Sub OnPaint(ByVal e As >>>> System.Windows.Forms.PaintEventArgs) >>>> Dim rect As System.Drawing.Rectangle = New >>>> System.Drawing.Rectangle(10, 10, Me.Width - 20, Me.Height - 20) >>>> Dim gradientBrush As System.Drawing.Drawing2D.LinearGradientBrush >>>> gradientBrush = New >>>> System.Drawing.Drawing2D.LinearGradientBrush(rect, _ >>>> System.Drawing.Color.Gray, >>>> _ >>>> >>>> System.Drawing.Color.FloralWhite, _ >>>> >>>> System.Drawing.Drawing2D.LinearGradientMode.Vertical) >>>> e.Graphics.FillRectangle(gradientBrush, rect) >>>> End Sub >>>> End Class >>>> >>>> generates a control with an rectangle drawn inside. >>>> The problem is that an unusual line (colored Color.FloralWhite) appears >>>> on >>>> the top edge of the rectangle. This line should not be there. >>>> If LinearGradientMode id other than Vertical the problem persists, but >>>> it is >>>> less visible (only a small colored pixel is visible). >>>> >>>> Please note that the anomaly appears only with some rectangle sizes. >>>> Example: >>>> if rect={X=10,Y=10,Width=304,Height=208} 'equivalent to a Me.Size=New >>>> Size(324,228) - Anomaly visible >>>> if rect={X=10,Y=10,Width=304,Height=216} 'Correct, anomaly not visible >>>> >>>> Could someone PLEASE try to reproduce the problem (just copy code as >>>> is) and >>>> confirm that is an error and then reason with me?? >>>> >>>> Thank you!. >>>> >>>> Carlo >>>> >>>> (MCP) >>>> >>>> >>> >>> >> >> > >
Change the WrapMode to TileFlipXY.
Regards, Frank Hileman check out VG.net: http://www.vgdotnet.com Animated vector graphics system Integrated Visual Studio .NET graphics editor [quoted text, click to view] "Carlo, MCP" <carlodevREMOVE@gmail.com> wrote in message news:OHcaTG1xFHA.3588@tk2msftngp13.phx.gbl... > Hello Bob > I'm very glad to meet you on the ng. I recently used your page named "The > ToolboxBitmap puzzle"! > > Thank you for the suggestion. Applying your suggestion means that I'll get > rectangles that overflows my needs by 1 pixel. > Unfortunately, this is unacceptable for my needs since I calculate > rectangles sizes based on MeasureString for a very accurate placement of > text(s) and image(s) on the control. > Thank you for replying > > Carlo > > > > "Bob Powell [MVP]" <bob@_spamkiller_bobpowell.net> ha scritto nel > messaggio news:%2322vS30xFHA.1284@tk2msftngp13.phx.gbl... >> This is a known error (at least known to me) with LinearGradientBrush. It >> seems that the colour gradient is calculated slightly too short. The >> work-around is to make the gradient 1 pixel larger than the destination >> drawing rectangle. >> >> -- >> Bob Powell [MVP] >> Visual C#, System.Drawing >> >> Ramuseco Limited .NET consulting >> http://www.ramuseco.com >> >> Find great Windows Forms articles in Windows Forms Tips and Tricks >> http://www.bobpowell.net/tipstricks.htm >> >> Answer those GDI+ questions with the GDI+ FAQ >> http://www.bobpowell.net/faqmain.htm >> >> All new articles provide code in C# and VB.NET. >> Subscribe to the RSS feeds provided and never miss a new article. >> >> >> >> >> >> "Carlo" <Carlo@discussions.microsoft.com> wrote in message >> news:2D471195-83E4-4C85-BE52-602F7512ACCE@microsoft.com... >>> Hello >>> >>> I found an abnormal behaviour on LinearGradientBrush (or FillRectangle). >>> This code >>> >>> Public Class PanelPanel >>> Inherits System.Windows.Forms.Panel >>> Protected Overrides Sub OnPaint(ByVal e As >>> System.Windows.Forms.PaintEventArgs) >>> Dim rect As System.Drawing.Rectangle = New >>> System.Drawing.Rectangle(10, 10, Me.Width - 20, Me.Height - 20) >>> Dim gradientBrush As System.Drawing.Drawing2D.LinearGradientBrush >>> gradientBrush = New >>> System.Drawing.Drawing2D.LinearGradientBrush(rect, _ >>> System.Drawing.Color.Gray, >>> _ >>> >>> System.Drawing.Color.FloralWhite, _ >>> >>> System.Drawing.Drawing2D.LinearGradientMode.Vertical) >>> e.Graphics.FillRectangle(gradientBrush, rect) >>> End Sub >>> End Class >>> >>> generates a control with an rectangle drawn inside. >>> The problem is that an unusual line (colored Color.FloralWhite) appears >>> on >>> the top edge of the rectangle. This line should not be there. >>> If LinearGradientMode id other than Vertical the problem persists, but >>> it is >>> less visible (only a small colored pixel is visible). >>> >>> Please note that the anomaly appears only with some rectangle sizes. >>> Example: >>> if rect={X=10,Y=10,Width=304,Height=208} 'equivalent to a Me.Size=New >>> Size(324,228) - Anomaly visible >>> if rect={X=10,Y=10,Width=304,Height=216} 'Correct, anomaly not visible >>> >>> Could someone PLEASE try to reproduce the problem (just copy code as is) >>> and >>> confirm that is an error and then reason with me?? >>> >>> Thank you!. >>> >>> Carlo >>> >>> (MCP) >>> >>> >> >> > >
WrapMode works both with LinearGradientBrush and PathGradientBrush. Just set
the WrapMode property on gradientBrush before you draw with it. Here is the problem: internally GDI+ has a small rounding error when computing the start and end coordinates of the gradient. This results in 1 pixel of the next gradient showing in your rectangle. Since the default WrapMode is Tile, the next gradient will begin with a contrasting color, so that 1 pixel line is obvious. If you change the wrap mode to flip the gradient, the next gradient will begin with the same color which just ended, and the error is no longer visible. Regards, Frank Hileman check out VG.net: http://www.vgdotnet.com Animated vector graphics system Integrated Visual Studio .NET graphics editor [quoted text, click to view] "Carlo, MCP" <carlodevREMOVE@gmail.com> wrote in message news:ecsjFuQyFHA.2516@TK2MSFTNGP12.phx.gbl... >I never heard about WrapMode before. I've seen it is applicable only to >PathGradientBrush. > I've no ideas on how draw my gradient rectangles using PathGradientBrush > (and WrapMode). > > Could you please be more precise or write a pair of rows as an example? > > This is my original code: > > Dim rect As Rectangle = New Rectangle(10, 10, Me.Width - 20, Me.Height - > 20) > Dim gradientBrush As Drawing2D.LinearGradientBrush > gradientBrush = New Drawing2D.LinearGradientBrush(rect, Color.Gray, > Color.FloralWhite, Drawing2D.LinearGradientMode.Vertical) > e.Graphics.FillRectangle(gradientBrush, rect) > > > Thank you, and regards, > > Carlo
I never heard about WrapMode before. I've seen it is applicable only to
PathGradientBrush. I've no ideas on how draw my gradient rectangles using PathGradientBrush (and WrapMode). Could you please be more precise or write a pair of rows as an example? This is my original code: Dim rect As Rectangle = New Rectangle(10, 10, Me.Width - 20, Me.Height - 20) Dim gradientBrush As Drawing2D.LinearGradientBrush gradientBrush = New Drawing2D.LinearGradientBrush(rect, Color.Gray, Color.FloralWhite, Drawing2D.LinearGradientMode.Vertical) e.Graphics.FillRectangle(gradientBrush, rect) Thank you, and regards, Carlo [quoted text, click to view] > Change the WrapMode to TileFlipXY. > > Regards, > Frank Hileman > > check out VG.net: http://www.vgdotnet.com > Animated vector graphics system > Integrated Visual Studio .NET graphics editor > > "Carlo, MCP" <carlodevREMOVE@gmail.com> wrote in message > news:OHcaTG1xFHA.3588@tk2msftngp13.phx.gbl... >> Hello Bob >> I'm very glad to meet you on the ng. I recently used your page named "The >> ToolboxBitmap puzzle"! >> >> Thank you for the suggestion. Applying your suggestion means that I'll >> get rectangles that overflows my needs by 1 pixel. >> Unfortunately, this is unacceptable for my needs since I calculate >> rectangles sizes based on MeasureString for a very accurate placement of >> text(s) and image(s) on the control. >> Thank you for replying >> >> Carlo >> >> >> >> "Bob Powell [MVP]" <bob@_spamkiller_bobpowell.net> ha scritto nel >> messaggio news:%2322vS30xFHA.1284@tk2msftngp13.phx.gbl... >>> This is a known error (at least known to me) with LinearGradientBrush. >>> It seems that the colour gradient is calculated slightly too short. The >>> work-around is to make the gradient 1 pixel larger than the destination >>> drawing rectangle. >>> >>> -- >>> Bob Powell [MVP] >>> Visual C#, System.Drawing >>> >>> Ramuseco Limited .NET consulting >>> http://www.ramuseco.com >>> >>> Find great Windows Forms articles in Windows Forms Tips and Tricks >>> http://www.bobpowell.net/tipstricks.htm >>> >>> Answer those GDI+ questions with the GDI+ FAQ >>> http://www.bobpowell.net/faqmain.htm >>> >>> All new articles provide code in C# and VB.NET. >>> Subscribe to the RSS feeds provided and never miss a new article. >>> >>> >>> >>> >>> >>> "Carlo" <Carlo@discussions.microsoft.com> wrote in message >>> news:2D471195-83E4-4C85-BE52-602F7512ACCE@microsoft.com... >>>> Hello >>>> >>>> I found an abnormal behaviour on LinearGradientBrush (or >>>> FillRectangle). >>>> This code >>>> >>>> Public Class PanelPanel >>>> Inherits System.Windows.Forms.Panel >>>> Protected Overrides Sub OnPaint(ByVal e As >>>> System.Windows.Forms.PaintEventArgs) >>>> Dim rect As System.Drawing.Rectangle = New >>>> System.Drawing.Rectangle(10, 10, Me.Width - 20, Me.Height - 20) >>>> Dim gradientBrush As System.Drawing.Drawing2D.LinearGradientBrush >>>> gradientBrush = New >>>> System.Drawing.Drawing2D.LinearGradientBrush(rect, _ >>>> System.Drawing.Color.Gray, >>>> _ >>>> >>>> System.Drawing.Color.FloralWhite, _ >>>> >>>> System.Drawing.Drawing2D.LinearGradientMode.Vertical) >>>> e.Graphics.FillRectangle(gradientBrush, rect) >>>> End Sub >>>> End Class >>>> >>>> generates a control with an rectangle drawn inside. >>>> The problem is that an unusual line (colored Color.FloralWhite) appears >>>> on >>>> the top edge of the rectangle. This line should not be there. >>>> If LinearGradientMode id other than Vertical the problem persists, but >>>> it is >>>> less visible (only a small colored pixel is visible). >>>> >>>> Please note that the anomaly appears only with some rectangle sizes. >>>> Example: >>>> if rect={X=10,Y=10,Width=304,Height=208} 'equivalent to a Me.Size=New >>>> Size(324,228) - Anomaly visible >>>> if rect={X=10,Y=10,Width=304,Height=216} 'Correct, anomaly not visible >>>> >>>> Could someone PLEASE try to reproduce the problem (just copy code as >>>> is) and >>>> confirm that is an error and then reason with me?? >>>> >>>> Thank you!. >>>> >>>> Carlo >>>> >>>> (MCP) >>>> >>>> >>> >>> >> >> > >
Thank you for the reply and for the suggestion. I'm very happy because it
works! Best Regards, Carlo "Frank Hileman" <frankhil@no.spamming.prodigesoftware.com> ha scritto nel messaggio news:O2EMVUSyFHA.916@TK2MSFTNGP10.phx.gbl... [quoted text, click to view] > WrapMode works both with LinearGradientBrush and PathGradientBrush. Just > set the WrapMode property on gradientBrush before you draw with it. > > Here is the problem: internally GDI+ has a small rounding error when > computing the start and end coordinates of the gradient. This results in 1 > pixel of the next gradient showing in your rectangle. Since the default > WrapMode is Tile, the next gradient will begin with a contrasting color, > so that 1 pixel line is obvious. If you change the wrap mode to flip the > gradient, the next gradient will begin with the same color which just > ended, and the error is no longer visible. > > Regards, > Frank Hileman > > check out VG.net: http://www.vgdotnet.com > Animated vector graphics system > Integrated Visual Studio .NET graphics editor > > "Carlo, MCP" <carlodevREMOVE@gmail.com> wrote in message > news:ecsjFuQyFHA.2516@TK2MSFTNGP12.phx.gbl... >>I never heard about WrapMode before. I've seen it is applicable only to >>PathGradientBrush. >> I've no ideas on how draw my gradient rectangles using PathGradientBrush >> (and WrapMode). >> >> Could you please be more precise or write a pair of rows as an example? >> >> This is my original code: >> >> Dim rect As Rectangle = New Rectangle(10, 10, Me.Width - 20, Me.Height - >> 20) >> Dim gradientBrush As Drawing2D.LinearGradientBrush >> gradientBrush = New Drawing2D.LinearGradientBrush(rect, Color.Gray, >> Color.FloralWhite, Drawing2D.LinearGradientMode.Vertical) >> e.Graphics.FillRectangle(gradientBrush, rect) >> >> >> Thank you, and regards, >> >> Carlo > >
Don't see what you're looking for? Try a search.
|
March 2004
April 2004
May 2004
June 2004
July 2004
August 2004
September 2004
October 2004
November 2004
December 2004
January 2005
February 2005
March 2005
April 2005
May 2005
June 2005
July 2005
August 2005
September 2005
October 2005
November 2005
December 2005
January 2006
February 2006
March 2006
April 2006
May 2006
June 2006
July 2006
August 2006
September 2006
October 2006
November 2006
December 2006
January 2007
February 2007
March 2007
April 2007
May 2007
June 2007
July 2007
August 2007
September 2007
October 2007
November 2007
December 2007
February 2008
April 2008
May 2008
June 2008
| home · blog · groups | Questions? Comments? Contact the dn |