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C# File.SetLastAccessTimeUtc()用法及代碼示例

File.SetLastAccessTimeUtc(String,DateTime)是一個內置的File類方法,該方法用於以協調世界時(UTC)設置最後一次訪問指定文件的日期和時間。

用法:

public static void SetLastAccessTimeUtc (string path, DateTime lastAccessTimeUtc);

參數:此函數接受兩個參數,如下所示:



  • path: This is the file for which to set the access date and time information.
  • lastAccessTime: This is the specified last access date and time, expressed in UTC time.

異常:

  • ArgumentException:路徑為長度為零的字符串,僅包含空格,或者由InvalidPathChars定義的一個或多個無效字符。
  • ArgumentNullException:路徑為空。
  • PathTooLongException:指定的路徑,文件名或兩者都超過了system-defined的最大長度。
  • FileNotFoundException:找不到指定的路徑。
  • UnauthorizedAccessException:調用者沒有所需的權限。
  • NotSupportedException:路徑格式無效。
  • ArgumentOutOfRangeException:lastAccessTime指定一個超出此操作允許的日期或時間範圍的值。

下麵是說明File.SetLastAccessTimeUtc(String,DateTime)方法的程序。

程序1:在運行下麵的代碼之前,將創建一個文件file.txt,其內容如下所示:

file.txt

// C# program to illustrate the usage 
// of File.SetLastAccessTimeUtc() method 
  
// Using System and System.IO namespaces 
using System; 
using System.IO; 
  
class GFG { 
    public static void Main() 
    { 
        // Specifing a file 
        string myfile = @"file.txt"; 
  
        // Calling the SetLastAccessTimeUtc() function 
        // to set last access date and time 
        File.SetLastAccessTimeUtc(myfile, new DateTime(2020, 5, 4, 4, 5, 7)); 
  
        // Getting the last access date and time 
        DateTime dt = File.GetLastAccessTimeUtc(myfile); 
        Console.WriteLine("The last access date and "+ 
             "time in UTC for this file was {0}.", dt); 
    } 
}

輸出:

The last access date and time in UTC for this file was 5/4/2020 4:05:07 AM.

程序2:最初,沒有創建文件。下麵的代碼本身創建了一個文件file.txt並顯示了上次訪問的日期和時間。

// C# program to illustrate the usage 
// of File.SetLastAccessTimeUtc() method 
  
// Using System and System.IO namespaces 
using System; 
using System.IO; 
  
class GFG { 
    public static void Main() 
    { 
        // Specifing a file 
        string path = @"file.txt"; 
  
        // Checking the existance of the file 
        if (!File.Exists(path)) { 
            File.Create(path); 
        } 
  
        // Calling the SetLastAccessTimeUtc() function 
        // to set last access date and time 
        File.SetLastAccessTimeUtc(path, new DateTime(2019, 5, 4, 4, 5, 7)); 
  
        // Getting the last access date and time 
        DateTime dt = File.GetLastAccessTimeUtc(path); 
        Console.WriteLine("The last access date and time "+ 
                      "in UTC for this file was {0}.", dt); 
    } 
}

執行中:

The last access date and time in UTC for this file was 5/4/2019 4:05:07 AM.



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注:本文由純淨天空篩選整理自Kanchan_Ray大神的英文原創作品 File.SetLastAccessTimeUtc() Method in C# with Examples。非經特殊聲明,原始代碼版權歸原作者所有,本譯文未經允許或授權,請勿轉載或複製。