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); 

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

 //Or

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

这不是处理上述问题的最佳方法。但这是另一种选择。。。

while (Directory.GetDirectories(dirpath).Length > 0)
 {
       //Delete all files in directory
       while (Directory.GetFiles(Directory.GetDirectories(dirpath)[0]).Length > 0)
       {
            File.Delete(Directory.GetFiles(dirpath)[0]);
       }
       Directory.Delete(Directory.GetDirectories(dirpath)[0]);
 }

此版本不使用递归调用，并解决了只读问题。

public static void EmptyDirectory(string directory)
{
    // First delete all the files, making sure they are not readonly
    var stackA = new Stack<DirectoryInfo>();
    stackA.Push(new DirectoryInfo(directory));

    var stackB = new Stack<DirectoryInfo>();
    while (stackA.Any())
    {
        var dir = stackA.Pop();
        foreach (var file in dir.GetFiles())
        {
            file.IsReadOnly = false;
            file.Delete();
        }
        foreach (var subDir in dir.GetDirectories())
        {
            stackA.Push(subDir);
            stackB.Push(subDir);
        }
    }

    // Then delete the sub directories depth first
    while (stackB.Any())
    {
        stackB.Pop().Delete();
    }
}

使用DirectoryInfo的GetDirectories方法。

foreach (DirectoryInfo subDir in new DirectoryInfo(targetDir).GetDirectories())
                    subDir.Delete(true);

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();
    }
}