windows - Kernel32 CopyFile does not find a file which exists c# -

i invoked kernel32's copy file method that:

[dllimport("kernel32.dll",            charset = charset.unicode,            callingconvention = callingconvention.stdcall,            setlasterror = true)]         [return: marshalas(unmanagedtype.bool)]         static extern bool copyfile(                            [marshalas(unmanagedtype.lpstr)] string lpexistingfilename,                            [marshalas(unmanagedtype.lpstr)] string lpnewfilename,                            [marshalas(unmanagedtype.bool)] bool bfailifexists); [dllimport("kernel32.dll")]     public static extern uint getlasterror(); 

however when call it return 2 getlasterror() means file not found. path exists.

string newfile = environment.currentdirectory + "\\temp" + path.getextension(file); uint i; if (!copyfile(file, newfile, true)) = getlasterror(); 

i'm trying bypass longpath exception solution. doesn't seem work normal files. appreciated.

here's complete code of form1:

using system; using system.collections.generic; using system.componentmodel; using system.data; using system.drawing; using system.linq; using system.text; using system.windows.forms; using system.io; using shell32; using system.xml; using system.diagnostics; using word = microsoft.office.interop.word; using system.runtime.interopservices;  namespace documentcrawler {     public partial class form1 : form     {         [dllimport("kernel32.dll",            charset = charset.unicode,            callingconvention = callingconvention.stdcall,            setlasterror = true)]         [return: marshalas(unmanagedtype.bool)]         static extern bool copyfile(                            [marshalas(unmanagedtype.lpstr)] string lpexistingfilename,                            [marshalas(unmanagedtype.lpstr)] string lpnewfilename,                            [marshalas(unmanagedtype.bool)] bool bfailifexists);          [dllimport("kernel32.dll")]         public static extern uint getlasterror();          public form1()         {             initializecomponent();         }          private void btnsearch_click(object sender, eventargs e)         {             progressbar.style = progressbarstyle.marquee;             lbprogress.text = "finding word documents";             btnsearch.enabled = false;             lvresults.clear();             searchdirectory(tbdirectory.text, tbfield.text);             btnsearch.enabled = true;         }          void searchdirectory(string path, string searchpattern)         {             list<string> docs = new list<string>();             foreach (string d in directory.getdirectories(path))             {                 searchdirectory(path + "\\" + d.remove(0, d.lastindexof('\\') + 1), searchpattern);             }              foreach (string f in directory.getfiles(path))             {                 if (path.getextension(f) == ".docx" || path.getextension(f) == ".doc")                 {                     docs.add(f);                 }             }              progressbar.value = 0;             lbprogress.text = "processing word documents 0%";             progressbar.maximum = docs.count;             progressbar.style = progressbarstyle.blocks;              foreach (string f in docs)             {                 string txt = textfromdocument(f);                 if (txt.contains(searchpattern))                 {                     lvresults.items.add(f);                 }                 progressbar.value++;                 lbprogress.text = "processing word documents " + ((int)((float)progressbar.value / (float)progressbar.maximum * 100)) + "%";             }         }          string textfromdocument(string file)         {             string newfile = environment.currentdirectory + "\\temp" + path.getextension(file);             uint i;             if (!copyfile(file, newfile, true)) = getlasterror();             object nullobj = system.reflection.missing.value;             word.application wordapp = new word.application();             word.document doc = wordapp.documents.open(newfile, false);              doc.activewindow.selection.wholestory();             doc.activewindow.selection.copy();             string text = doc.content.text;              doc.close(ref nullobj, ref nullobj, ref nullobj);             wordapp.quit(ref nullobj, ref nullobj, ref nullobj);              file.delete(newfile);              return text;         }          private void lvresults_doubleclick(object sender, eventargs e)         {             process.start(lvresults.selecteditems[0].text);             lvresults.selecteditems[0].forecolor = color.purple;         }          private void btnbrowse_click(object sender, eventargs e)         {             folderbrowserdialog fd = new folderbrowserdialog();             if (fd.showdialog() == dialogresult.ok)             {                 tbdirectory.text = fd.selectedpath;                 btnsearch.enabled = true;             }         }     } } 

thanks in advance!

[dllimport("kernel32.dll",    charset = charset.unicode,    callingconvention = callingconvention.stdcall,    setlasterror = true)] [return: marshalas(unmanagedtype.bool)] static extern bool copyfile(                    [marshalas(unmanagedtype.lpstr)] string lpexistingfilename,                    [marshalas(unmanagedtype.lpstr)] string lpnewfilename,                    [marshalas(unmanagedtype.bool)] bool bfailifexists); 

in dllimport declaration select charset.unicode character set. mean p/invoke function bound copyfilew.

but subsequently instruct marshaller marshal parameters lpstr, ansi strings. reason why function fails.

a correct p/invoke be:

[dllimport("kernel32.dll", charset = charset.unicode, setlasterror = true)] static extern bool copyfile(string lpexistingfilename, string lpnewfilename,     bool bfailifexists); 

you absolutely should not p/invoke getlasterror. instead use marshal.getlastwin32error reasons described in documentation.