C# File.SetLastWriteTime()用法及代碼示例

File.SetLastWriteTime(String)是一個內置的File類方法，用於設置指定文件的最後寫入日期和時間。

用法:

public static void SetLastWriteTime (string path, DateTime lastWriteTime);

參數：此函數接受兩個參數，如下所示：

path: This is the specified file for which to set the date and time information.

lastWriteTime: This is the specified local last write date and time of the path.

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：lastWriteTime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.SetLastWriteTime(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：

// C# program to illustrate the usage 
// of File.SetLastWriteTime() 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 SetLastWriteTime() function 
        // to set last written date and time 
        File.SetLastWriteTime(myfile, new DateTime(2020, 
                                         5, 4, 4, 5, 7)); 
  
        // Getting the last written date and time 
        // of the file 
        DateTime dt = File.GetLastWriteTime(myfile); 
        Console.WriteLine("The last written date and "+ 
                     "time for this file was {0}.", dt); 
    } 
}

輸出：

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

程序2:最初，沒有創建文件。在代碼下方，其自身創建文件file.txt並打印最後寫入的日期和時間。

// C# program to illustrate the usage 
// of File.SetLastWriteTime() 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 SetLastWriteTime() function 
        // to set last written date and time 
        File.SetLastWriteTime(path, new DateTime(2019, 
                                      5, 4, 4, 5, 7)); 
  
        // Getting the last written date and time 
        // of the specified file 
        DateTime dt = File.GetLastWriteTime(path); 
        Console.WriteLine("The last written date and "+ 
                     "time for this file was {0}.", dt); 
    } 
}

執行中：

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

相關用法

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.SetLastWriteTime() 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。