为什么上传不了图片到文件夹？

Question

要把一个图片上传到UpFile文件夹，是文件夹的共享设置还是什么问题？代码如下，哪位给看看如何改？  
private  void  btn_PostUp_Click(object  sender,  System.EventArgs  e)  
           {  
                       string  Path;  
                       string  FileName;  
                       int  Po;  
                       long  FileSize;  
                       string  fType;  
                       if(File1.PostedFile.FileName.Trim()!="")      
                       {  
                                   try  
                                   {  
                                               Path=Server.MapPath("\\BookShop\\UpFile").ToString();  
                                               FileName=File1.PostedFile.FileName.ToString();  
                                               fType=File1.PostedFile.ContentType;    
                                               FileSize=File1.PostedFile.ContentLength;      
                                               if(fType.Substring(0,5)!="image")  
                                               {  
                                                           ShowErrMsg("PostFile  is  not  Image!");  
                                                           return;  
                                               }  
                                               Po=FileName.LastIndexOf((char)92);  
                                               FileName=FileName.Substring(Po+1,FileName.Length  -Po-1);  
                                               ViewState["PostFileName"]=FileName;                                  
                                               File1.PostedFile.SaveAs(Path+"\\"+FileName);    
                                               img_BookImg.ImageUrl="UpFile\\"+FileName;  
                                   }  
                                   catch(Exception  er)  
                                   {  
                                               ShowErrMsg(er.Message);  
                                   }  
                       }  
           }

Answer 1

这个比较好看些
private void btn_PostUp_Click(object sender, System.EventArgs e)
{
string Path;
string FileName;
int Po;
long FileSize;
string fType;
if(File1.PostedFile.FileName.Trim()!="")  
{
try
{
Path=Server.MapPath("\\BookShop\\UpFile").ToString();
FileName=File1.PostedFile.FileName.ToString();
fType=File1.PostedFile.ContentType; 
FileSize=File1.PostedFile.ContentLength;  
if(fType.Substring(0,5)!="image")
{
ShowErrMsg("PostFile is not Image!");
return;
}
Po=FileName.LastIndexOf((char)92);
FileName=FileName.Substring(Po+1,FileName.Length -Po-1);
ViewState["PostFileName"]=FileName;                
File1.PostedFile.SaveAs(Path+"\\"+FileName); 
img_BookImg.ImageUrl="UpFile\\"+FileName;
}
catch(Exception er)
{
ShowErrMsg(er.Message);
}
}
}

Answer 2

Server.MapPath("BookShop/UpFile")//虚拟路径