FileSystemWatcher.Path 屬性

定義

命名空間:

System.IO

組件:

netstandard.dll, System.IO.FileSystem.Watcher.dll

來源:

FileSystemWatcher.cs

取得或設定目錄的路徑要監視。

public:
 property System::String ^ Path { System::String ^ get(); void set(System::String ^ value); };

public string Path { get; set; }

member this.Path : string with get, set

Public Property Path As String

屬性值

String

監控的路徑。 預設為空字串（“”）。

例外狀況

ArgumentException

指定的路徑不存在或找不到。

-或-

指定的路徑包含通配字元。

-或-

指定的路徑包含無效的路徑字元。

範例

以下範例建立一個 FileSystemWatcher ，以監控執行時指定的目錄。 元件設定為監控目錄中文字檔的建立、刪除或重新命名時間的變化LastWriteLastAccess。 如果檔案被更改、建立或刪除，該檔案的路徑會印到主控台。 當檔案被重新命名時，舊路徑和新路徑會印到主控台。

using System;
using System.IO;

namespace MyNamespace
{
    class MyClassCS
    {
        static void Main()
        {
            using var watcher = new FileSystemWatcher(@"C:\path\to\folder");

            watcher.NotifyFilter = NotifyFilters.Attributes
                                 | NotifyFilters.CreationTime
                                 | NotifyFilters.DirectoryName
                                 | NotifyFilters.FileName
                                 | NotifyFilters.LastAccess
                                 | NotifyFilters.LastWrite
                                 | NotifyFilters.Security
                                 | NotifyFilters.Size;

            watcher.Changed += OnChanged;
            watcher.Created += OnCreated;
            watcher.Deleted += OnDeleted;
            watcher.Renamed += OnRenamed;
            watcher.Error += OnError;

            watcher.Filter = "*.txt";
            watcher.IncludeSubdirectories = true;
            watcher.EnableRaisingEvents = true;

            Console.WriteLine("Press enter to exit.");
            Console.ReadLine();
        }

        private static void OnChanged(object sender, FileSystemEventArgs e)
        {
            if (e.ChangeType != WatcherChangeTypes.Changed)
            {
                return;
            }
            Console.WriteLine($"Changed: {e.FullPath}");
        }

        private static void OnCreated(object sender, FileSystemEventArgs e)
        {
            string value = $"Created: {e.FullPath}";
            Console.WriteLine(value);
        }

        private static void OnDeleted(object sender, FileSystemEventArgs e) =>
            Console.WriteLine($"Deleted: {e.FullPath}");

        private static void OnRenamed(object sender, RenamedEventArgs e)
        {
            Console.WriteLine($"Renamed:");
            Console.WriteLine($"    Old: {e.OldFullPath}");
            Console.WriteLine($"    New: {e.FullPath}");
        }

        private static void OnError(object sender, ErrorEventArgs e) =>
            PrintException(e.GetException());

        private static void PrintException(Exception? ex)
        {
            if (ex != null)
            {
                Console.WriteLine($"Message: {ex.Message}");
                Console.WriteLine("Stacktrace:");
                Console.WriteLine(ex.StackTrace);
                Console.WriteLine();
                PrintException(ex.InnerException);
            }
        }
    }
}

Imports System.IO

Namespace MyNamespace

    Class MyClassVB

        Shared Sub Main()
            Using watcher = New FileSystemWatcher("C:\path\to\folder")
                watcher.NotifyFilter = NotifyFilters.Attributes Or
                                       NotifyFilters.CreationTime Or
                                       NotifyFilters.DirectoryName Or
                                       NotifyFilters.FileName Or
                                       NotifyFilters.LastAccess Or
                                       NotifyFilters.LastWrite Or
                                       NotifyFilters.Security Or
                                       NotifyFilters.Size

                AddHandler watcher.Changed, AddressOf OnChanged
                AddHandler watcher.Created, AddressOf OnCreated
                AddHandler watcher.Deleted, AddressOf OnDeleted
                AddHandler watcher.Renamed, AddressOf OnRenamed
                AddHandler watcher.Error, AddressOf OnError

                watcher.Filter = "*.txt"
                watcher.IncludeSubdirectories = True
                watcher.EnableRaisingEvents = True

                Console.WriteLine("Press enter to exit.")
                Console.ReadLine()
            End Using
        End Sub

        Private Shared Sub OnChanged(sender As Object, e As FileSystemEventArgs)
            If e.ChangeType <> WatcherChangeTypes.Changed Then
                Return
            End If
            Console.WriteLine($"Changed: {e.FullPath}")
        End Sub

        Private Shared Sub OnCreated(sender As Object, e As FileSystemEventArgs)
            Dim value As String = $"Created: {e.FullPath}"
            Console.WriteLine(value)
        End Sub

        Private Shared Sub OnDeleted(sender As Object, e As FileSystemEventArgs)
            Console.WriteLine($"Deleted: {e.FullPath}")
        End Sub

        Private Shared Sub OnRenamed(sender As Object, e As RenamedEventArgs)
            Console.WriteLine($"Renamed:")
            Console.WriteLine($"    Old: {e.OldFullPath}")
            Console.WriteLine($"    New: {e.FullPath}")
        End Sub

        Private Shared Sub OnError(sender As Object, e As ErrorEventArgs)
            PrintException(e.GetException())
        End Sub

        Private Shared Sub PrintException(ex As Exception)
            If ex IsNot Nothing Then
                Console.WriteLine($"Message: {ex.Message}")
                Console.WriteLine("Stacktrace:")
                Console.WriteLine(ex.StackTrace)
                Console.WriteLine()
                PrintException(ex.InnerException)
            End If
        End Sub

    End Class

End Namespace

備註

這是通往目錄的完整合格路徑。 若 IncludeSubdirectories 屬性為 true，則該目錄為系統監控變更的根目錄;否則它是唯一被監控的目錄。 要監控特定檔案，將屬性設 Path 為完全合格且正確的目錄，並將 Filter 屬性設為檔案名稱。

此 Path 屬性支援通用命名規則（UNC）路徑。

備註

必須先設定此屬性，元件才能觀察變化。

當目錄被重新命名時，它 FileSystemWatcher 會自動重新附加到新命名的項目上。 例如，如果你將屬性設 Path 為「C：\My Documents」，然後手動將目錄重新命名為「C：\Your Documents」，元件會繼續監聽新命名目錄的變更通知。 然而，當你詢問該 Path 房產時，它包含了舊路徑。 這是因為元件根據帳柄而非目錄名稱來決定哪些目錄要被監視。 重新命名不會影響帳柄。 所以，如果你先摧毀元件，然後在沒有更新 Path 屬性的情況下重新建立它，你的應用程式會失敗，因為該目錄已經不存在了。

另請參閱

• FileSystemWatcher
• Filter