public static void DelectDir(string srcPath)
{
    try
    {
         DirectoryInfo dir = new DirectoryInfo(srcPath);
         FileSystemInfo[] fileinfo = dir.GetFileSystemInfos();  //返回目录中所有文件和子目录
         foreach (FileSystemInfo i in fileinfo)
         {
             if (i is DirectoryInfo)            //判断是否文件夹
             {
                  DirectoryInfo subdir = new DirectoryInfo(i.FullName);
                  subdir.Delete(true);          //删除子目录和文件
             } 
             else
             {
                  File.Delete(i.FullName);      //删除指定文件
             }
         }                
    }
    catch (Exception e)
    {
         throw;
    }
}

if(Directory.Exists(srcPath))
{
    DelectDir(srcPath);
}