Question

我正在尝试使用Vb.Net中的Json对象从SQL服务器检索数据。我将检索到的值添加到datatable但是添加的值没有显示在aspx页面中。为什么？

我的代码：

客户端：

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>View</title>
</head>
<body>
<form id="form1" runat="server">
<table border="0" >
    <tr>
        <td>
            <asp:Label ID= "lblName" runat="server" Text="Name" ></asp:Label>
        </td>
        <td>
            <asp:TextBox ID="txtName" runat="server" Text="" /><br />
        </td>
    </tr>
    <tr>
            <td> &nbsp </td>
    </tr>
    <tr>
        <td colspan ="2" >
           <asp:Button ID="btnShow" Text="Show" runat="server" />
        </td>
    </tr>
</table>
    <hr />
    <asp:GridView ID="gvUsers" runat="server" AutoGenerateColumns="false" HeaderStyle-BackColor="#3AC0F2"
    HeaderStyle-ForeColor="White" RowStyle-BackColor="#A1DCF2">
    </asp:GridView>
</form>
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/json2/0.2/json2.js"></script>
 <script type="text/javascript">
    $(document).ready(function () {
        BindGridView();
    });
    function BindGridView() {
         $("[id*=btnShow]").bind("click", function () {
            var user = {};
            user.Name = $("[id*=txtName]").val();
            $.ajax({
                type: "POST",
                url: "View.aspx/ViewUser",
                data: '{user: ' + JSON.stringify(user) + '}',
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                success: function (data) {
                    response(data.t);
                    $("#gvUsers").empty();
                        if (data.d.length > 0) {
                        $("#gvUsers").append("<tr><th>Username</th><th>Password</th></tr>");
                        for (var i = 0; i < response.d.length; i++) {
                            $("#gvUsers").append("<tr><td>" +
                            response.d[i].Username + "</td> <td>" +
                            response.d[i].Password + "</td></tr>");
                        }
                    }

                }
            });
            return;
            });
        };
        </script>
    </body>
</html>

代码背后：

Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration
Imports System.Web.Services
Imports System.Web.Script.Services
Imports System.Collections.Generic


Partial Class View
Inherits System.Web.UI.Page

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    If Not IsPostBack Then
      BindDummyItem()
    End If
End Sub
Public Sub BindDummyItem()
    Dim dtGetData As New DataTable()
    dtGetData.Columns.Add("Username")
    dtGetData.Columns.Add("Password")
    dtGetData.Rows.Add()

    gvUsers.DataSource = dtGetData
    gvUsers.DataBind()
End Sub

<WebMethod()> _
<ScriptMethod()> _
Public Shared Sub ViewUser(user As Users)
    Dim Detail As New List(Of Users)()
    Dim dt As New DataTable()
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As New SqlConnection(constr)
        Using cmd As New SqlCommand("SELECT * FROM Users WHERE Username = @Name")
            Using sda As New SqlDataAdapter()
                cmd.CommandType = CommandType.Text
                cmd.Parameters.AddWithValue("@Name", user.Name)
                cmd.Connection = con
                sda.SelectCommand = cmd
                sda.Fill(dt)

                For Each dtRow As DataRow In dt.Rows
                    Dim DataObj As New Users()
                    DataObj.Name = dtRow("Username").ToString()
                    DataObj.Password = dtRow("Password").ToString()


                    Detail.Add(DataObj)
                Next
            End Using
        End Using
    End Using
    Return
  End Sub
End Class
Public Class Users
  Public Property Name() As String
    Get
        Return _Name
    End Get
    Set(value As String)
        _Name = value
    End Set
End Property
Private _Name As String

Public Property Password As String
    Get
        Return _Password
    End Get
    Set(Value As String)
        _Password = Value
    End Set
End Property
Private _Password As String
End Class

执行此代码时，检索到的值会添加到详细信息列表中，但不会显示在网页中。告诉我这是检索数据的正确程序？提前谢谢。

Answer 1

这个怎么样：

 cmd.CommandType = CommandType.Text
 cmd.Parameters.AddWithValue("@Name", user.Name)
 cmd.Connection = con
 sda.SelectCommand = cmd
 sda.Fill(dt)


 gvUsers.DataSource = dt
 gvUsers.DataBind()

使用Json对象（webmethod）重新传输数据不会显示在aspx页面中

1 个答案: