的GridView並沒有在頁面加載在C＃中顯示

Question

protected void Page_Load(object sender, EventArgs e) 
      { 
       if (!IsPostBack) 
       { 
        SqlConnection con = Connection.DBconnection(); 
        { 
         SqlCommand com = new SqlCommand("sp_selectlendingstatus", con); 
         com.CommandType = CommandType.StoredProcedure; 
         com.Parameters.AddWithValue("@studentid", txtstudentid.Text.Trim()); 
         com.Parameters.AddWithValue("@bookid", txtbookid.Text.Trim()); 
         com.Parameters.AddWithValue("@status", status.Text.Trim()); 
         SqlDataAdapter sda = new SqlDataAdapter(com); 
         DataSet ds = new DataSet(); 
         sda.Fill(ds); 
         GridView1.DataSource = ds; 
         GridView1.DataBind(); 
        } 
       } 
      } 

ASPX：

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" 
     DataKeyNames="ID" EnablePersistedSelection="True" BackColor="White" 
     Height="240px" 
     Width="755px"> 
     <Columns> 
     <asp:BoundField DataField="ID" HeaderText="Student_Id" InsertVisible="False" ReadOnly="True" SortExpression="ID" /> 
      <asp:BoundField DataField="Book_id" HeaderText="Book_id" InsertVisible="False" ReadOnly="True" SortExpression="Book_id" />     
      <asp:BoundField DataField="Book_name" HeaderText="Book_name" SortExpression="Book_name" /> 
      <asp:BoundField DataField="Author_name" HeaderText="Author_name" SortExpression="Author_name" /> 
      <asp:BoundField DataField="Publisher_name" HeaderText="Publish_name" SortExpression="Publisher_name" /> 
      <asp:BoundField DataField="Publish_date" HeaderText="Publish_date" SortExpression="Publish_date" /> 
      <asp:BoundField DataField="status" HeaderText="Status" SortExpression="status" /> 
      </Columns> 
      </asp:GridView> 

SP：

ALTER PROCEDURE sp_selectlendingstatus 

AS 
Begin 
select * from book_lending left outer join studentlibrary ON studentlibrary.Book_id=book_lending.bookid 
End 

我是新來的.NET ..

在頁面加載，我需要顯示gridview。

我試過以上的源代碼，但是當我運行gridview沒有顯示。

它顯示錯誤，sp_selectlendingstatus沒有參數傳遞。

所以，如果我添加參數在這樣sp_selectlendingstatus程序，

ALTER PROCEDURE sp_selectlendingstatus 
(
@bookid int, 
@studentid int, 
@status varchar(50) 
) 
AS 
Begin 
select * from book_lending left outer join studentlibrary ON studentlibrary.Book_id=book_lending.bookid 
End 

，並運行在SQL Server EXEC sp_selectlendingstatus。

它顯示錯誤@studentid，@bookid沒有提供。

我可以知道我的代碼中有什麼錯誤嗎？

任何幫助將不勝感激。

感謝，

Answer 1

根據您的選擇查詢，你可以編寫以下format.Before綁定，您必須檢查網格中的所有列檢索名稱出現在在GridView否則拋出錯誤。

private void BindStudents() 
{ 
String strConnStr = ConfigurationManager.ConnectionStrings["conStr"].ConnectionString; 
SqlConnection con = new SqlConnection(strConnStr); 
SqlCommand cmd = new SqlCommand(); 
cmd.CommandType = CommandType.StoredProcedure; 
cmd.CommandText = "sp_selectlendingstatus"; 
cmd.Connection = con; 
try 
{ 
    con.Open(); 
    GridView1.EmptyDataText = "No Records Found"; 
    GridView1.DataSource = cmd.ExecuteReader() ; 
    GridView1.DataBind(); 
} 
catch (Exception ex) 
{ 
    throw ex; 
} 
finally 
{ 
    con.Close(); 
    con.Dispose(); 
} 
}