ERRORR MESSAGE GOT ANSISTRING EXPECTED SHORTSTRING

http://community.freepascal.org:10000/bboards/message?message_id=263454&forum_id=24083

 

 

 

Hello! Who an help me? I get the following error message in gimages.pp in line 271: Error: call by var parameters have to match exactly: Got ANSISTRING expected SHORTSTRING function LoadImage( Dir, FileName: string; var P: PImageCanvas; DesiredBPP: Word ): Boolean;   var     Dirr,Name,Ext: string;     R: PImageReader;     S: PStream;   begin     FSplit( FileName, Dirr, Name, Ext ); // here i get the error     FileName := FSearch( FileName, Dir+';'+Dirr+';'+'.\');     if FileName = '' then       begin         P := nil; The {$H+} directive brings no success. I tried two methods: 1.)   var   {$H+}  Dirr,Name,Ext: string; {$H-}   no success. I get the same error message. 2.)   I gave the {$H+} directive before LoadImage() function.   After LoadImage() function i gave {$H-} directive.   no success. I get the same error message. What goes wrong here? Thanks alredy for your help!

-- Thomas Schönfelder, 2007年 11月月 22日 10:48 下午

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答案：

> Thanks alredy for your help! I hope this doesn't mean you aren't going to post a reply after someone helps. If the original poster doesn't reply after help is given, the person who helped has no idea whether his answer was read by the o.p. {$H+} is very cryptic; I had to look it up. {$longstrings on} is easier to understand. I had to look up "fsplit" also, but I didn't know which unit to look in. Using "dos.fsplit" would help readers of your program, especially since you left out the "uses dos" in the fragment above. Does the compiler directive {$longstrings on} or {$h+} appear anywhere else in your program? That would seem to be the problem. If so, you want to turn longstrings off (not on with {$h+}) when defining the function load_image. In the future, please show all compiler directives and "uses" that could affect the code that you post. This works for me: {$longstrings on} uses dos; {$longstrings off} procedure show_parts( file_name: string ); var dir,name,ext: string; begin dos.fsplit( file_name, dir, name, ext ); writeln( dir ); writeln( name ); writeln( ext ); end; {$longstrings on} var path: string; begin path := 'c:\here\foo.bar'; show_parts( path ); end. Note that if the variable "path" is longer than 255 characters, only the first 255 charcters will be received by the procedure "show_parts", since its parameter is a short string. Another way to make sure that a string variable is a short string, not an ansistring, is to specify a maximal size: var dir,name,ext: string[255];

-- Steve Fisher, 2007年 11月月 23日 01:47 上午

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I noticed that it's possible to typecast ansistring to shortstring. Try this: FSplit( shortstring(FileName), shortstring(Dirr), shortstring(Name), shortstring(Ext) );
-- Mario Ray Mahardhika, 2007年 11月月 23日 05:54 上午	(E-mail)

Hello! @Steve: Thank's for your help. To parenthise the used dos unit with the longstrings on/ff directive works for me. @Mario: The other version, the typecast to shortstring brings me the error message ...different type size (4 -> 256). Only the Steves version works for me. In spite of this, thank you too. You see, my "Thank's alredy for your help" doesn't mean that i don't replay an answer. I whish you both a nice weekend. Thomas

-- Thomas Schönfelder, 2007年 11月月 23日 10:59 上午

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The most standard / simplest solution obviously is changing the declaration to the following: var dir,name,ext: shortstring; The other option obviously is to add {$H-} or {$LONGSTRINGS OFF} before the declaration, that effectively does the same.
-- Tomas Hajny, 2007年 11月月 23日 12:34 下午	(E-mail)

another possable answer is to use {R+} (openstring on) will cause all string passes to be flexable size this seems to help. you can deline a variable as openstring instead of string or shortstring.
-- Allen Harrington, 2007年 11月月 30日 02:28 下午	(E-mail)