| Description |
The WaitForChanged method waits until the specified ChangeType occurs in the current path. The wait is indefinite unless the WaitLimitMiiilseconds value is specified.
The ChangeType must be one of the following :
| All | The creation, deletion, change, or renaming of a file or folder. |
| Changed | The change of a file or folder. The types of changes include: changes to size, attributes, security settings, last write, and last access time. |
| Created | The creation of a file or folder. |
| Deleted | The deletion of a file or folder. |
| Renamed | The renaming of a file or folder. |
The returned WaitForChangedResult holds information about the change :
| ChangeType | The type of change that occurred. |
| Name | The name of the file or directory that changed. |
| OldName | The original name of the file or directory that was renamed. |
| TimedOut | A value indicating whether the wait operation timed out. |
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| Microsoft MSDN Links |
System.IO
System.IO.FileSystemWatcher
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| Waiting for any file system access |
program Project1;
{$APPTYPE CONSOLE}
uses
System.IO;
var
MyWatcher : System.IO.FileSystemWatcher;
begin
// Create a FileSystemWatcher object
MyWatcher := FileSystemWatcher.Create('C:\');
// Watch for any file access
MyWatcher.NotifyFilter := NotifyFilters.LastAccess;
// Now we wait until an event occurs
MyWatcher.WaitForChanged(WatcherChangeTypes.Changed);
// Indicate a file has been accessed
Console.WriteLine('A file or folder has been accessed');
Console.Readline;
end.
| | Show full unit code | When a C:\ file or folder is accessed, the above code produces the following message :
A file or folder has been accessed
| | | Waiting for a file to be renamed | program Project1;
{$APPTYPE CONSOLE}
uses
System.IO;
var
MyWatcher : System.IO.FileSystemWatcher;
ChangeResult : System.IO.WaitForChangedResult;
begin
// Create a FileSystemWatcher object
MyWatcher := FileSystemWatcher.Create('C:\');
// Watch for access to a file (which we will rename)
MyWatcher.NotifyFilter := NotifyFilters.FileName;
// Now we wait until an event occurs
ChangeResult := MyWatcher.WaitForChanged(WatcherChangeTypes.Renamed);
// Indicate a file has been renamed
Console.WriteLine('{0} renamed to {1}',
ChangeResult.OldName,
ChangeResult.Name);
Console.Readline;
end.
| | Show full unit code | After renaming a file in the C:\ folder, the following message was produced :
DelphiBasics.txt renamed to RenamedDelphiBasics.txt
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