抛出异常

if(System.IO.Directory.Exists(value))
                {
                    this.skindir=value;
                    gowk.utility.IO.Regestry.SetValue(SkinDirectoryKey,skindir);
                    if(this.SkinChanged!=null)this.SkinChanged(this,System.EventArgs.Empty);
                }        
                else
                {
                    throw(new System.IO.FileNotFoundException("不能加载皮肤目录"));
                }