private void ClearDirectory(string path)
{
    if (Directory.Exists(path))//if folder exists
    {
        Directory.Delete(path, true);//recursive delete (all subdirs, files)
    }
    Directory.CreateDirectory(path);//creates empty directory
}

下面的示例显示了如何做到这一点。它首先创建一些目录和文件，然后通过Directory.Delete（topPath，true）；：

    static void Main(string[] args)
    {
        string topPath = @"C:\NewDirectory";
        string subPath = @"C:\NewDirectory\NewSubDirectory";

        try
        {
            Directory.CreateDirectory(subPath);

            using (StreamWriter writer = File.CreateText(subPath + @"\example.txt"))
            {
                writer.WriteLine("content added");
            }

            Directory.Delete(topPath, true);

            bool directoryExists = Directory.Exists(topPath);

            Console.WriteLine("top-level directory exists: " + directoryExists);
        }
        catch (Exception e)
        {
            Console.WriteLine("The process failed: {0}", e.Message);
        }
    }

它取自https://msdn.microsoft.com/en-us/library/fxeahc5f（v=vs.110）.aspx。

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); 

要删除文件夹，这是使用文本框的代码和使用System.IO；的按钮：

private void Deletebt_Click(object sender, EventArgs e)
{
    System.IO.DirectoryInfo myDirInfo = new DirectoryInfo(@"" + delete.Text);

    foreach (FileInfo file in myDirInfo.GetFiles())
    {
       file.Delete();
    }
    foreach (DirectoryInfo dir in myDirInfo.GetDirectories())
    {
       dir.Delete(true);
    }
}

System.IO.Directory.Delete(installPath, true);
System.IO.Directory.CreateDirectory(installPath);

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);