Improve company productivity with a Business Account.Sign Up

x
?
Solved

remove the background from EMF

Posted on 2002-05-08
4
Medium Priority
?
517 Views
Last Modified: 2010-04-04
I have a metafile that has been captured from a TRichEdit. As the Rich edit has a white background, so does the metafile. I need to remove this background from the metafile to make it transparent.

The only way I can see to do this is by using EnumEnhMetaFile, and removing the entries that setbkcolor but I can't work out how to do this.

Can anyone tell me how to do this or suggest another way of making the metafile transparent.

Cheers in advance
0
Comment
Question by:mike_tipping
4 Comments
 
LVL 4

Expert Comment

by:nestorua
ID: 6997062
HI,
As if the Help says:
"Description
Transparent specifies whether that the metafile be drawn transparently. TMetafile overrides the write method of the Transparent property to essentially make the property read-only, so setting the property for this object does not change their behavior,"
yuo can't change its Transparent property to True when it is False (if it is True you have no problem).
So, I propose the following:
1.Create new Metafile with Create method.
(in this case newly created Metafile has its Transparent=True)2.Assign to created Metafile that copied from the Richedit.
(It seems the transparent property isn't assigning)
Sincerely,
Nestorua.
0
 

Author Comment

by:mike_tipping
ID: 6998431
I think this bit of the help is meaning that the transparent property makes no difference to the background of the tmetafile. A metafile is a collection of GDI calls that play onto the display canvas so a 'transparent' metafile is actualy onw with no background. Looking at the GDI help there are 2 GDI calls that appear in my metafile setbkcolor and setbkmode and I beleive these are what I need to get rid of or change.

I may be wrong but that's my thinking
0
 
LVL 35

Accepted Solution

by:
Slick812 earned 800 total points
ID: 7002367
hello mike_tipping, As you have found out, the TMetaFile transparent property does not do anything. I had the opossite problem, the metafiles were transparent and I did not want that. Since the drawing operations for a metafile are in an array of records, if those drawing operations draw a background, then it may be difficult to stop it. What I would do id copy it to a Bitmap and Transparent the bitmap.


procedure TForm1.sbut_LoadWmfClick(Sender: TObject);
var
Wmf1: TMetaFile;
TempBmp: TBitmap;
begin
Wmf1 := TMetafile.Create;
Wmf1.LoadFromFile('C:\Temp\Wmf1.wmf');
TempBmp := TBitmap.Create;
TempBmp.Height := Wmf1.Height;
TempBmp.Width := Wmf1.Width;
TempBmp.Canvas.Draw(0,0,Wmf1);
TempBmp.Transparent := True;
//TempBmp.TransparentColor := clWhite;
PaintBox8.Canvas.Draw(0,0,TempBmp);
FreeAndNil(Wmf1);
FreeAndNil(TempBmp);
end;


Changing the drawing operations of a Metafile may be alot more dificult. Hope this helps you.
0
 
LVL 1

Expert Comment

by:pnh73
ID: 9005325
No comment has been added lately, so it's time to clean up this TA.
I will leave a recommendation in the Cleanup topic area that this question is:

Accept answer from Slick812

Please leave any comments here within the next seven days.
 
PLEASE DO NOT ACCEPT THIS COMMENT AS AN ANSWER!
 
Paul (pnh73)
EE Cleanup Volunteer
0

Featured Post

Get your problem seen by more experts

Be seen. Boost your question’s priority for more expert views and faster solutions

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Hello everybody This Article will show you how to validate number with TEdit control, What's the TEdit control? TEdit is a standard Windows edit control on a form, it allows to user to write, read and copy/paste single line of text. Usua…
Introduction I have seen many questions in this Delphi topic area where queries in threads are needed or suggested. I know bumped into a similar need. This article will address some of the concepts when dealing with a multithreaded delphi database…
In response to a need for security and privacy, and to continue fostering an environment members can turn to for support, solutions, and education, Experts Exchange has created anonymous question capabilities. This new feature is available to our Pr…
Watch the video to know the process of migration of Exchange or Office 365 mailboxes in absence of MS Outlook. It is an eminent tool which can easily migrate Public, Archive user mailboxes from one another Exchange server and Office 365. Kernel Migr…

595 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question