您code看起来很好.......你是说你已经分配的权限了。 唯一的问题是，你可能会传递一个错误的源，这是造成problem..Check您的源字符串可能有一个错误......

Your code look fine.......you are saying that you have assigned permission too. The only problem is that you may be passing a wrong "Source"which is causing problem..Check your source string it may have an error......

路径应

 WebRequest request = WebRequest.Create("ftp://host.com/directory123");

这意味着目录将与名为directory12创建 如果您要指定这样的路径

it mean directory will be created with name "directory12" if your are specifying path like this

 WebRequest request = WebRequest.Create("ftp://host.com/directory123/directory1234");

这意味着 ftp://host.com/directory123/ 应该已经存在，新目录将被命名为directory1234创建 希望这将有助于

this mean "ftp://host.com/directory123/" should already exist and new directory will be created with name "directory1234" hope it will help