Directory.GetLastWriteTime(String) 方法
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
傳回指定檔案或目錄上次被寫入的日期和時間。
public:
static DateTime GetLastWriteTime(System::String ^ path);public static DateTime GetLastWriteTime (string path);static member GetLastWriteTime : string -> DateTimePublic Shared Function GetLastWriteTime (path As String) As DateTime參數
- path
- String
要取得其修改日期和時間資訊的檔案或目錄。
傳回
結構，設定為指定之檔案或目錄上次被寫入的日期和時間。 這個值以本地時間表示。
例外狀況
呼叫端沒有必要的權限。
.NET Framework 和 2.1 之前的 .NET Core 版本：path是長度為零的字串、只包含空格符，或包含一或多個無效的字元。 您可以使用 GetInvalidPathChars() 方法查詢無效字元。
path 為 null。
指定的路徑、檔案名稱，或兩者都超出系統定義的長度上限。
範例
下列範例示範如何使用 GetLastWriteTime。
using namespace System;
using namespace System::IO;
int main()
{
try
{
String^ path = "c:\\MyDir";
if ( !Directory::Exists( path ) )
{
Directory::CreateDirectory( path );
}
else
{
// Take an action which will affect the write time.
Directory::SetLastWriteTime( path, DateTime(1985,4,3) );
}
// Get the creation time of a well-known directory.
DateTime dt = Directory::GetLastWriteTime( path );
Console::WriteLine( "The last write time for this directory was {0}", dt );
// Update the last write time.
Directory::SetLastWriteTime( path, DateTime::Now );
dt = Directory::GetLastWriteTime( path );
Console::WriteLine( "The last write time for this directory was {0}", dt );
}
catch ( Exception^ e )
{
Console::WriteLine( "The process failed: {0}", e );
}
}
using System;
using System.IO;
class Test
{
public static void Main()
{
try
{
string path = @"c:\MyDir";
if (!Directory.Exists(path))
{
Directory.CreateDirectory(path);
}
else
{
// Take an action which will affect the write time.
Directory.SetLastWriteTime(path, new DateTime(1985,4,3));
}
// Get the creation time of a well-known directory.
DateTime dt = Directory.GetLastWriteTime(path);
Console.WriteLine("The last write time for this directory was {0}", dt);
// Update the last write time.
Directory.SetLastWriteTime(path, DateTime.Now);
dt = Directory.GetLastWriteTime(path);
Console.WriteLine("The last write time for this directory was {0}", dt);
}
catch (Exception e)
{
Console.WriteLine("The process failed: {0}", e.ToString());
}
}
}
open System
open System.IO
try
let path = @"c:\MyDir"
if not (Directory.Exists path) then
Directory.CreateDirectory path |> ignore
else
// Take an action which will affect the write time.
Directory.SetLastWriteTime(path, DateTime(1985, 4, 3))
// Get the creation time of a well-known directory.
let dt = Directory.GetLastWriteTime path
printfn $"The last write time for this directory was {dt}"
// Update the last write time.
Directory.SetLastWriteTime(path, DateTime.Now)
let dt = Directory.GetLastWriteTime path
printfn $"The last write time for this directory was {dt}"
with e ->
printfn $"The process failed: {e}"
Imports System.IO
Public Class Test
Public Shared Sub Main()
Try
Dim path As String = "c:\MyDir"
If Directory.Exists(path) = False Then
Directory.CreateDirectory(path)
Else
' Take an action which will affect the write time.
Directory.SetLastWriteTime(path, New DateTime(1985, 4, 3))
End If
' Get the creation time of a well-known directory.
Dim dt As DateTime = Directory.GetLastWriteTime(path)
Console.WriteLine("The last write time for this directory was {0}", dt)
' Update the last write time.
Directory.SetLastWriteTime(path, DateTime.Now)
dt = Directory.GetLastWriteTime(path)
Console.WriteLine("The last write time for this directory was {0}", dt)
Catch e As Exception
Console.WriteLine("The process failed: {0}", e.ToString())
End Try
End Sub
End Class
備註
注意
這個方法可能會傳回不正確的值，因為它會使用操作系統可能不會持續更新其值的原生函式。
如果參數中所述的 path 目錄不存在，這個方法會傳回 12：00 午夜，1601 A.D. (C.E.) 國際標準時間 (UTC) ，調整為當地時間。
允許 path 參數指定相對路徑或絕對路徑資訊。 相對路徑資訊會解譯為相對於目前的工作目錄。 若要取得目前的工作目錄，請參閱 GetCurrentDirectory。
參數的 path 區分大小寫會對應至執行程式碼的文件系統。 例如，在NTFS上不區分大小寫 (預設Windows檔案系統) 和Linux檔案系統上區分大小寫。
如需一般 I/O 工作的清單，請參閱 一般 I/O 工作。
