To implement a file watcher in Delphi, you will need to use the TFileSystemWatcher class, which is part of the System.IOUtils unit. This class allows you to monitor changes to files and directories on the file system, and provides events that are fired when changes occur.
Here is an example of how you might use the TFileSystemWatcher class to implement a file watcher in Delphi:
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uses System.IOUtils; var FileSystemWatcher: TFileSystemWatcher; begin // Create a new TFileSystemWatcher instance FileSystemWatcher := TFileSystemWatcher.Create(nil); // Set the directory to watch FileSystemWatcher.Path := ‘C:\MyFiles’; // Set the filter to watch for specific file types FileSystemWatcher.Filter := ‘*.txt’; // Set the events to watch for FileSystemWatcher.OnChange := FileChanged; FileSystemWatcher.OnCreate := FileCreated; FileSystemWatcher.OnDelete := FileDeleted; // Enable the file system watcher FileSystemWatcher.Active := True; // … // Event handler for the OnChange event procedure FileChanged(Sender: TObject; const FileName: string); begin WriteLn(FileName, ‘ was changed.’); end; // Event handler for the OnCreate event procedure FileCreated(Sender: TObject; const FileName: string); begin WriteLn(FileName, ‘ was created.’); end; // Event handler for the OnDelete event procedure FileDeleted(Sender: TObject; const FileName: string); begin WriteLn(FileName, ‘ was deleted.’); end; end; |
In this example, we create a new TFileSystemWatcher instance and set the directory to watch and the filter for the file types to watch for. We then set the event handlers for the OnChange, OnCreate, and OnDelete events, and enable the file system watcher. When a change occurs to a file in the specified directory, the corresponding event handler is called and takes appropriate action.
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