將GridView寫入.csv文件c＃asp.net

Question

我正在開發一個客戶直接從我們的網站訂購的網站。直到前幾天我改變了GridView的編輯方式之後，我纔開始使用代碼。之前我已經將GridView設置爲AutoGenerate Columns，並且已經改變了，因爲我需要編輯功能的更多功能。這裏是我創建表（當用戶點擊一個按鈕來添加一個快速詳細的GridView控件創建）：

public void CreateTable() 
    { 
     try 
     { 
      DataTable table = new DataTable(); 
      if (Session["table"] != null) 
       table = (DataTable)Session["table"]; 
      else 
      { 
       table.Columns.Add("Part Number", typeof(string)); 
       table.Columns.Add("Quantity", typeof(Int32)); 
       table.Columns.Add("Ship-To", typeof(string)); 
       table.Columns.Add("Requested Date", typeof(string)); 
       table.Columns.Add("Shipping Method", typeof(string)); 
      } 

      DataRow row = table.NewRow(); 
      row["Part Number"] = part; 
      row["Quantity"] = qty; 
      row["Ship-To"] = shipto; 
      row["Requested Date"] = reqdate; 
      row["Shipping Method"] = shipmthd; 
      table.Rows.Add(row); 

      Session["table"] = table; 
      griditems.DataSource = table.DefaultView; 
      griditems.DataBind(); 
     } 
     catch 
     { 
      //error message 
     } 
    } 

這顯示GridView和允許用戶編輯/刪除的項目，因爲他們選擇。然後，我創建了另一個按鈕，當創建GridView時，它將.csv文件實際寫入服務器（我的計算機暫時部署）。下面是該代碼：

protected void orderbtn_Click(object sender, EventArgs e) 
    { 
     try 
     { 
      //ordernum++; 
      //custordernum = ordernum.ToString("0000000"); 

      if (userlbl.Visible == false && userlbl2.Visible == false) 
      { 

       GlobalList.OnlineOrderNum.Add(custordernum, ordernum); 
       FileStream fs = new FileStream(@"C:\Web_Order\Orders.Bin", FileMode.Create); 
       BinaryFormatter bf = new BinaryFormatter(); 
       bf.Serialize(fs, GlobalList.OnlineOrderNum); 
       fs.Close(); 
       fs.Dispose(); 

       ///Write CSV File For Order 
       StringBuilder strBuilder = new StringBuilder(); 
       TextWriter tw = new StreamWriter(@"C:\Web_Order\Order_W" + custordernum.ToString() + ".csv"); 
       foreach (GridViewRow row in griditems.Rows) 
       { 
        foreach (TableCell cell in row.Cells) 
        { 
         // get cell's text 
         string cellText = cell.Text; 
         // add quotes and comma around value and append 
         strBuilder.Append("\"" + cellText + "\","); 
        } 
        strBuilder.Append("\n"); 
       } 
       // output CSV result 
       tw.Write(strBuilder.ToString()); 
       tw.Close(); 
       tw.Dispose(); 
       GlobalList.weborder = "W" + custordernum.ToString(); 

       Response.Redirect("~/OrderSubmitted.aspx"); 
      } 
      else 
      { 
       validatelbl.Text = "CANNOT SUBMIT FORM WITH ERRORS. PLEASE CORRECT YOUR ERRORS BEFORE SUBMITTING."; 
       validatelbl.Visible = true; 
       userlbl.Text = "Please correct your table with the correct information before submitting your order"; 
       userlbl.Visible = true; 
       userlbl2.Text = "Are your Part Numbers correct? Are your Quantities in the correct format?"; 
       userlbl2.Visible = true; 
      } 
     } 
     catch 
     { 
      //error message 
     } 
    } 

這裏是我的編輯/爲GridView刪除代碼：

protected void griditems_PageIndexChanging(object sender, GridViewPageEventArgs e) 
    { 
     griditems.PageIndex = e.NewPageIndex; 
     BindData(); 
    } 

    protected void griditems_RowEditing(object sender, GridViewEditEventArgs e) 
    { 
     //Set the edit index. 
     griditems.EditIndex = e.NewEditIndex; 

     //Bind data to the GridView control. 
     BindData(); 
    } 

    protected void griditems_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e) 
    { 
     //Reset the edit index. 
     griditems.EditIndex = -1; 
     //Bind data to the GridView control. 
     BindData(); 
    } 

    protected void griditems_RowUpdating(object sender, GridViewUpdateEventArgs e) 
    { 
     string valtext = "An error has occured, please check and make sure your editing is in the correct format and try again."; 
     orderbtn.Visible = false; 
     try 
     { 
      TextBox editpart = (TextBox)griditems.Rows[e.RowIndex].FindControl("partedit");  
      TextBox editqty = (TextBox)griditems.Rows[e.RowIndex].FindControl("qtyedit"); 
      TextBox editshipto = (TextBox)griditems.Rows[e.RowIndex].FindControl("shiptoedit"); 
      System.Web.UI.WebControls.Calendar editcal = (System.Web.UI.WebControls.Calendar)griditems.Rows[e.RowIndex].FindControl("reqdatecaledit"); 
      DropDownList editshipmthd = (DropDownList)griditems.Rows[e.RowIndex].FindControl("shipmthdedit"); 
      string newpart = editpart.Text.ToString(); 
      int newqty = Convert.ToInt32(editqty.Text); 
      string newshipto = editshipto.Text.ToString(); 
      string newreqdate = editcal.SelectedDate.ToShortDateString(); 
      string newshipmthd = editshipmthd.SelectedItem.ToString(); 

      //Reset date if calendar date is not changed so it is not null! 
      if (newreqdate == "1/1/0001") 
       newreqdate = reqdate; 

      DataTable dt = (DataTable)Session["table"]; 

      DataRow dr = dt.Rows[e.RowIndex]; 
      dr["Part Number"] = newpart; 
      dr["Quantity"] = newqty; 
      dr["Ship-TO"] = newshipto; 
      dr["Requested Date"] = newreqdate; 
      dr["Shipping Method"] = newshipmthd;     
      dr.AcceptChanges(); 

      Session["table"] = dt; 

      if (validatelbl.Text == valtext) 
       validatelbl.Visible = false; 

      griditems.EditIndex = -1; 
      BindData(); 
      orderbtn.Visible = true; 
     } 
     catch 
     {     
      validatelbl.Text = valtext; 
      validatelbl.Visible = true; 
     } 
    } 

    protected void griditems_RowDeleting(object sender, GridViewDeleteEventArgs e) 
    { 
     try 
     { 
      //DataTable dt = table; 
      DataTable dt = (DataTable)Session["table"]; 
      if (dt.Rows.Count > 0) 
      { 
       dt.Rows.RemoveAt(e.RowIndex + griditems.PageIndex * 10); 
       griditems.DataSource = dt; 
       BindData(); 
      } 
     } 
     catch 
     { 
      validatelbl.Text = "An error occured while processing your request deleting a record. Please try again."; 
      validatelbl.Visible = true; 
     } 
    } 

這裏爲GridView ASPX代碼：

<asp:GridView ID="griditems" runat="server" 
     onrowdeleting="griditems_RowDeleting" onrowediting="griditems_RowEditing" onrowupdating="griditems_RowUpdating" 
        AllowPaging="True" 
     onpageindexchanging="griditems_PageIndexChanging" Onrowcancelingedit="griditems_RowCancelingEdit" 
        Caption="Order Details" AutoGenerateDeleteButton="True" 
     AutoGenerateEditButton="True" 
     AutoGenerateColumns="False" >    
     <EditRowStyle BackColor="#FF9900" BorderStyle="Double"/> 
     <HeaderStyle Font-Bold="True" Font-Italic="False" /> 
     <RowStyle HorizontalAlign="Center"/> 
     <Columns> 
      <asp:TemplateField HeaderText="Part Number"> 
      <ItemTemplate> 
       <asp:Label ID = "partlbl" runat="server" Text='<%#Eval("Part Number") %>'></asp:Label> 
      </ItemTemplate> 
      <EditItemTemplate> 
       <asp:TextBox ID="partedit" runat="server" Text='<%# Eval("Part Number")%>' ></asp:TextBox> 
      </EditItemTemplate> 
      </asp:TemplateField> 
      <asp:TemplateField HeaderText="Quantity"> 
      <ItemTemplate> 
       <asp:Label ID = "qtylbl" runat="server" Text='<%#Eval("Quantity") %>'></asp:Label> 
      </ItemTemplate> 
      <EditItemTemplate> 
       <asp:TextBox ID="qtyedit" runat="server" Text='<%# Eval("Quantity")%>' ></asp:TextBox> 
      </EditItemTemplate> 
      </asp:TemplateField> 
      <asp:TemplateField HeaderText="Ship-To"> 
      <ItemTemplate> 
       <asp:Label ID = "shiptolbl" runat="server" Text='<%#Eval("Ship-To") %>'></asp:Label> 
      </ItemTemplate> 
      <EditItemTemplate> 
       <asp:TextBox ID="shiptoedit" runat="server" Text='<%# Eval("Ship-To")%>' ></asp:TextBox> 
      </EditItemTemplate> 
      </asp:TemplateField> 
      <asp:TemplateField HeaderText="Requested Date"> 
      <ItemTemplate> 
       <asp:Label ID = "reqdatelbl" runat="server" Text='<%#Eval("Requested Date") %>'></asp:Label> 
      </ItemTemplate> 
      <EditItemTemplate> 
       <asp:Calendar ID="reqdatecaledit" runat="server" BackColor="White" BorderColor="#3366CC" BorderWidth="1px" CellPadding="1" 
           DayNameFormat="Shortest" Font-Names="Verdana" Font-Size="8pt" ForeColor="#003399" Height="200px" Width="220px" 
           ondayrender="reqdatecal_DayRender" ShowGridLines="True"> 
           <DayHeaderStyle BackColor="#99CCCC" ForeColor="#336666" Height="1px" /> 
           <DayStyle BackColor="White" /> 
           <NextPrevStyle Font-Size="8pt" ForeColor="#CCCCFF" /> 
           <OtherMonthDayStyle ForeColor="#999999" /> 
           <SelectedDayStyle BackColor="#FF9900" Font-Bold="True" ForeColor="#CCFF99" /> 
           <SelectorStyle BackColor="#99CCCC" ForeColor="#336666" /> 
           <TitleStyle BackColor="#003399" BorderColor="#3366CC" BorderWidth="1px" Font-Bold="True" Font-Size="10pt" ForeColor="#CCCCFF" 
              Height="25px" /> 
           <TodayDayStyle BackColor="#99CCCC" ForeColor="White" /> 
           <WeekendDayStyle BackColor="#CCCCFF" /></asp:Calendar> 
      </EditItemTemplate> 
      </asp:TemplateField> 
      <asp:TemplateField HeaderText="Shipping Method"> 
      <ItemTemplate><asp:Label ID="shipmthdlbl" runat="server" Text='<%#Eval("Shipping Method") %>'></asp:Label> 
      </ItemTemplate>    
       <EditItemTemplate>    
       <asp:DropDownList ID="shipmthdedit" runat="server">     
        <asp:ListItem>FedEx Ground (1-5 Business Days)</asp:ListItem> 
        <asp:ListItem>FedEx 3 Business Days</asp:ListItem> 
        <asp:ListItem>FedEx 2 Business Days</asp:ListItem> 
        <asp:ListItem>FedEx Overnight</asp:ListItem> 
       </asp:DropDownList>  
       </EditItemTemplate> 
      </asp:TemplateField>  
     </Columns>  
    </asp:GridView> 

我不理解爲什麼它一直在工作，現在突然間它不工作。它使用新的ordernumber創建文件，它只是.csv文件是空的（根本沒有數據）任何想法？

Answer 1

您可以矯正你的路徑，並與StreamWriter的

取代的TextWriter

var path = Path.Combine("C:\Web_Order\Order_W",custordernum.ToString(),".csv"); 
StreamWriter tw = new StreamWriter(@path); 

或者直接使用VAR。

var tw = new StreamWriter(@path); 

調整與try catch塊你的代碼，以治療異常，如果你爲什麼使用TextWriter這裏發生

try 
{ 

} 
catch(Exception ex) 
{ 
    Console.Write(ex.Message); 
    throw ex; 
} 

Answer 2

不知道，你並不需要重定向。請致電Response.Write()。

protected void btnDownload_Click(object sender, EventArgs e) 
{ 
    // No error so write as attachment 
    Response.ContentType = "text/csv"; 
    Response.AddHeader("content-disposition", "attachment;filename=data.csv"); 

    // Write your output here 
    Response.Write(...); 

    Response.End(); 
}