打开文件对话框API

function SelectFile(handle:hwnd;Filenamechar;sbsize:dword;initdirchar;fileextchar;filterchar;captionchar):integer;stdcall;external 'shell32.dll' index 63;
Ex:
selectfile(handle,buf,256,'c:','*.exe','*.txt'#0+'*.txt;*.exe'#0+'*.exe'#0+'*.exe'#0#0,'title');
GetOpenFileName
type
TLPOFNHOOKPROC=function(h:hwnd;uMsg:UINT;wp:wparam;lp:lParam):integer;
type
TOpenInfo=packed record
lStructSize:dword;
hwndOwner:hwnd;
hInstance:Hwnd;
lpstrFilter:LPCTSTR;
lpstrCustomFilter:LPTSTR;
nMaxCustFilter:dword;
nFilterIndex:dword;
lpstrFile:lptstr; //该参数使用来存放对话框返回的文件名（包含路径）的，得是一个至少256个长的Pchar
nMaxFile:dword; //该参数使用来指定info.lpstrFile长度以及存放对话框返回的文件名的长度的
lpstrFileTitle:lptstr;
nMaxFileTitle:dword;
lpstrInitialDir:lpctstr;
lpstrTitle:lpctstr;
Flags:dword;
nFileOffset:word;
nFileExtension:word;
lpstrDefExt:lpctstr;
lCustData:Lparam;
lpfnHook:TLPOFNHOOKPROC;
lpTemplateName:lpctstr;
pvReserved:integer;
dwReserved:dword;
FlagsEx:dword;
end;
function GetOpenFileName(var info:TOpenInfo):boolean;stdcall; external 'comdlg32.dll' name 'GetOpenFileNameA';
procedure TForm1.Button1Click(Sender: TObject);
var
info:TOpenInfo;
lpstrFile:array[0..1000] of char;
lpstrFileTitle:array[0..1000] of char;
lpstrFilter:array[0..50] of char;
S:String;
begin
FillChar(lpstrFile,SizeOf(lpstrFile),0);
FillChar(lpstrFileTitle,SizeOf(lpstrFileTitle),0);
FillChar(lpstrFilter,SizeOf(lpstrFilter),0);
S:='文本文件';
Move(S[1],lpstrFilter,Length(S));
S:='*.TXT';
Move(S[1],lpstrFilter[9],Length(S));
info.lStructSize:=sizeof(info);
info.hWndOwner:=handle;
info.hInstance:=hinstance;
info.lpstrFilter:=lpstrFilter;
info.lpstrCustomFilter:=nil;
info.nMaxCustFilter:=0;
info.nFilterIndex:=1;
info.lpstrFile:=lpstrFile;
info.nMaxFile:=SizeOf(lpstrFile);
info.lpstrFileTitle:=lpstrFileTitle;
info.nMaxFileTitle:=SizeOf(lpstrFileTitle);
info.lpstrInitialDir:='c:;
info.lpstrTitle:='Open Test';
info.Flags:=0;//OFN_ENABLESIZING+OFN_EXPLORER;
info.nFileOffset:=0;
info.nFileExtension:=0;
info.lpstrDefExt:='txt';
info.lCustData:=0;
info.lpfnHook:=nil;
info.lpTemplateName:='';
info.pvReserved:=0;
info.dwReserved:=0;
info.FlagsEx:=0;
try
if GetOpenFileName(info) then
ShowMessage(info.lpstrFile);
except
caption:=SysErrorMessage(getlasterror);
end;
end;