我尝试过的每一个方法都会在某个时候失败，并出现System.IO错误。即使文件夹为空或非空、只读或非只读等，以下方法也能正常工作。

ProcessStartInfo Info = new ProcessStartInfo();  
Info.Arguments = "/C rd /s /q \"C:\\MyFolder"";  
Info.WindowStyle = ProcessWindowStyle.Hidden;  
Info.CreateNoWindow = true;  
Info.FileName = "cmd.exe";  
Process.Start(Info); 

using System.IO;

string[] filePaths = Directory.GetFiles(@"c:\MyDir\");

foreach (string filePath in filePaths)

File.Delete(filePath);

 new System.IO.DirectoryInfo(@"C:\Temp").Delete(true);

 //Or

 System.IO.Directory.Delete(@"C:\Temp", true);

仅对File和Directory而不是FileInfo和DirectoryInfo使用静态方法将执行速度更快。（请参阅C#中File和FileInfo之间的区别是什么？）。答案显示为实用方法。

public static void Empty(string directory)
{
    foreach(string fileToDelete in System.IO.Directory.GetFiles(directory))
    {
        System.IO.File.Delete(fileToDelete);
    }
    foreach(string subDirectoryToDeleteToDelete in System.IO.Directory.GetDirectories(directory))
    {
        System.IO.Directory.Delete(subDirectoryToDeleteToDelete, true);
    }
}

private void ClearFolder(string FolderName)
{
    DirectoryInfo dir = new DirectoryInfo(FolderName);

    foreach(FileInfo fi in dir.GetFiles())
    {
        try
        {
            fi.Delete();
        }
        catch(Exception) { } // Ignore all exceptions
    }

    foreach(DirectoryInfo di in dir.GetDirectories())
    {
        ClearFolder(di.FullName);
        try
        {
            di.Delete();
        }
        catch(Exception) { } // Ignore all exceptions
    }
}

如果您知道没有子文件夹，那么像这样的操作可能是最简单的：

    Array.ForEach(Directory.GetFiles(folderName), File.Delete);

private void ClearFolder(string FolderName)
{
    DirectoryInfo dir = new DirectoryInfo(FolderName);

    foreach (FileInfo fi in dir.GetFiles())
    {
        fi.IsReadOnly = false;
        fi.Delete();
    }

    foreach (DirectoryInfo di in dir.GetDirectories())
    {
        ClearFolder(di.FullName);
        di.Delete();
    }
}