Question

我创建了一个绑定到本地SQL数据库文件（mdf）的GridView。数据库连接成功。我收到了来自我的EmptyDataText =＆＃34; No Data＆＃34;的错误消息。在GridView所假设的网页上。

非常感谢任何帮助。

这是我的div持有GridView：

   <div style="border: 10px hidden #0B4A80; height: 108px; width: 494px; overflow: auto; margin-bottom: 40px;" >
    <asp:SqlDataSource runat="server" ID="SqlDataSource1" 
      ConnectionString='<%$ ConnectionStrings:DefaultConnection %>' 
      SelectCommand="SELECT AspNetUsers.EmailConfirmed, AspNetUser.UserName, AspNetUsers.FirstName, AspNetUsers.LastName, AspNetUsers.BusinessName, AspNetRoles.Name FROM AspNetUsers INNER JOIN AspNetRoles ON AspNetUsers.Id = AspNetRoles.Id INNER JOIN AspNetUserRoles ON AspNetUsers.Id = AspNetUserRoles.UserId AND AspNetRoles.Id = AspNetUserRoles.RoleId"></asp:SqlDataSource>
    <asp:GridView ID="GridView2" runat="server" SelectMethod ="" UpdateMethod ="" AutoGenerateColumns="true" DataKeyNames="Id" EmptyDataText="No Data" EnableModelValidation="false" ForeColor="#333333" GridLines="None" BorderStyle="None" BorderWidth="10px" Height="75px" PageSize="3" Width="472px">
      <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
      <Columns>
        <asp:BoundField DataField="Text" HeaderText="User Information" />
        <asp:DynamicField DataField="EmailConfirmed" HeaderText="EmailConfirmed" SortExpression="EmailConfirmed"></asp:DynamicField>
        <asp:BoundField DataField="FirstName" HeaderText="First Name" SortExpression="FirstName"></asp:BoundField>
        <asp:BoundField DataField="LastName" HeaderText="Last Name" SortExpression="LastName"></asp:BoundField>
        <asp:DynamicField DataField="BusinessName" HeaderText="Business Name" SortExpression="BusinessName"></asp:DynamicField>
        <asp:DynamicField DataField="UserName" HeaderText="Email" SortExpression="UserName"></asp:DynamicField>
        <asp:DynamicField DataField="Name" HeaderText="Role"  SortExpression="Role" ></asp:DynamicField>
       </Columns>
      <EditRowStyle BackColor="#999999" />
      <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
      <HeaderStyle BackColor="#D7E4FF" Font-Bold="True" ForeColor="#1484AA" />
      <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
      <RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
      <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />          
    </asp:GridView>
  </div>

这是我的代码背后：

public partial class _Default : System.Web.UI.Page
{
  protected void Page_Load(object sender, EventArgs e)
  {
    if (!IsPostBack)
    {
      BindGrid1();
      BindGrid2();
    }

      private void BindGrid2()
      {
        String queryString = "SELECT [EmailConfirmed], [UserName], [FirstName], [LastName], [BusinessName], [Name] FROM AspNetUsers INNER JOIN AspNetRoles ON AspNetUsers.Id = AspNetRoles.Id INNER JOIN AspNetUserRoles ON AspNetUsers.Id = AspNetUserRoles.UserId AND AspNetRoles.Id = AspNetUserRoles.RoleId";
        DataSet ds = GetData(queryString);
        if (ds.Tables.Count > 0)
        {
          GridView2.DataSource = ds;
          GridView2.DataBind();
        }
        else
        {
          Response.Write("Unable to conenct to the database");
        }

      }

      DataSet GetData(String queryString)
      {
        //Retrive the connection string in the web.config file.
        String connectionString = ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString;

        DataSet ds = new DataSet();

        try
        {
          // Connect to the database and run query.
          SqlConnection connection = new SqlConnection(connectionString);
          SqlDataAdapter adapter = new SqlDataAdapter(queryString, connection);

          //Fill the dataSet.
          adapter.Fill(ds);
        }
        catch(System.Exception ex)
        {
          // The connection failed. Display an error message.
          Response.Write("Unable to connect to the database.");
          Response.Write(ex.Message);
        }
        return ds;
      }
   }
}

Answer 1

请删除您的代码隐藏数据库调用。您已经在ASPX页面的SQL数据源中填充了gridview。

<强> ASPX：

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="Id" DataSourceID="SqlDataSource1">
  <Columns>
      <asp:BoundField DataField="Id" HeaderText="Id" ReadOnly="True" SortExpression="Id" />
      <asp:BoundField DataField="Email" HeaderText="Email" SortExpression="Email" />
      <asp:CheckBoxField DataField="EmailConfirmed" HeaderText="EmailConfirmed" SortExpression="EmailConfirmed" />
      <asp:BoundField DataField="PasswordHash" HeaderText="PasswordHash" SortExpression="PasswordHash" />
      <asp:BoundField DataField="SecurityStamp" HeaderText="SecurityStamp" SortExpression="SecurityStamp" />
      <asp:BoundField DataField="PhoneNumber" HeaderText="PhoneNumber" SortExpression="PhoneNumber" />
      <asp:CheckBoxField DataField="PhoneNumberConfirmed" HeaderText="PhoneNumberConfirmed" SortExpression="PhoneNumberConfirmed" />
      <asp:CheckBoxField DataField="TwoFactorEnabled" HeaderText="TwoFactorEnabled" SortExpression="TwoFactorEnabled" />
      <asp:BoundField DataField="LockoutEndDateUtc" HeaderText="LockoutEndDateUtc" SortExpression="LockoutEndDateUtc" />
      <asp:CheckBoxField DataField="LockoutEnabled" HeaderText="LockoutEnabled" SortExpression="LockoutEnabled" />
      <asp:BoundField DataField="AccessFailedCount" HeaderText="AccessFailedCount" SortExpression="AccessFailedCount" />
      <asp:BoundField DataField="UserName" HeaderText="UserName" SortExpression="UserName" />
      <asp:BoundField DataField="TrialExpiration" HeaderText="TrialExpiration" SortExpression="TrialExpiration" />
      <asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" />
  </Columns>
</asp:GridView>

<asp:SqlDataSource runat="server" ID="SqlDataSource1" 
ConnectionString='......' SelectCommand="SELECT AspNetUsers.EmailConfirmed, AspNetUser.UserName, AspNetUsers.FirstName, AspNetUsers.LastName, AspNetUsers.BusinessName, AspNetRoles.Name FROM AspNetUsers LEFT OUTER JOIN AspNetUserRoles ON AspNetUsers.Id = AspNetUserRoles.UserId LEFT OUTER JOIN AspNetRoles ON AspNetRoles.Id = AspNetUserRoles.RoleId"></asp:SqlDataSource>

C＃代码隐藏：

public partial class _Default : Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
        }
    }
}

Answer 2

您是否忘记打开连接？

 using(SqlConnection connection = new SqlConnection(connectionString))
 {
      connection.Open();
      SqlDataAdapter adapter = new SqlDataAdapter(queryString, connection);

      //Fill the dataSet.
      adapter.Fill(ds);
 }

我的GridView不会填充来自我的SQL数据源

2 个答案: