Delphi provides many functions regarding file operations, where there is a directory creation and deletion of a directory operation, set the current directory, get the current directory, etc. The deletion of the directory has a function (Procedure) RMDIR, but they can only delete the empty directory, and they cannot be deleted for non-empty directories. To implement the deletion of the entire directory tree (Deltree) must write a program to delete the subdirectories and files.
The files in the directory can be deleted by calling the function deletefile, but for special files (read-only, system, hide, etc.) cannot be effectively deleted, and the file properties must be changed to delete. Changing file properties You can use FileSetattr, where the properties of special files are set to normal file properties (0).
Considering that the tree directory structure is best suited for recursive methods, all here uses a recursive algorithm to implement the Deltree function. The following is a specific implementation program.
// path is a directory path that needs to be deleted
// Directory Successfully Remove Returns True, otherwise returns false
Function TFORM1.DELTREE (PATH: STRING): Boolean;
VAR
SearchRec: tsearchrec;
Begin
/ / Judgment if the directory exists
If Directoryexists (PATH) THEN
Begin
// Enter the directory, delete the subdirectory and files
Olddir: = getcurrentdir;
CHDIR (PATH);
/ / Find all any files in the directory
Findfirst ('.', FAANYFILE, SEARCHREC);
Repeat
// Modify the file attribute to a normal attribute value
FileSetAttr (searchRec.name, 0);
// If it is a directory and is not. And .. recursive call Deltree
IF (SearchRec.attr And Fadirectory> 0) THEN
Begin
IF (SearchRec.name [1] <> '.') THEN
IF (not deltree) thein
Break;
end
// If you are the file directly delete
Else
IF (not deletefile (searchrec.name) then
Break;
/ / Continue to find until the end
Until (FindNext (SearchRec) <> 0);
/ / Back to the parent directory, delete the directory
Chdir ('..');
Result: = Removedir (PATH);
SetCurrentDir (Olddir);
end
Else
Result: = FALSE;
END;
This program compiles the passage under Windows 98, Delphi 4.0.
