.net - 如何使用 .NET 创建 JSON 数据？

Question

目前，我正在构建 json 数据，如下所示:

<%@ Page Language="VB" Debug="True" EnableViewState="false" %>

<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<%@ Import Namespace="System.IO" %>

<script runat="server">
    Dim objSQLConnection As SqlConnection
    Dim objSQLCommand As SqlCommand
    Dim objSQLDataReader As SqlDataReader
    Dim objJSONStringBuilder As StringBuilder

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
        Response.Clear()
        Response.ContentType = "application/json"
        Response.Write(get_json())
        Response.End()
    End Sub

    Function get_json() As String
        objJSONStringBuilder = New StringBuilder()
        objSQLConnection = New SqlConnection(System.Configuration.ConfigurationManager.AppSettings("connString"))

        objSQLCommand = New SqlCommand("sql query goes here", objSQLConnection)

        objJSONStringBuilder.Append("[")

        objSQLCommand.Connection.Open()
        objSQLDataReader = objSQLCommand.ExecuteReader()

        While objSQLDataReader.Read()
            objJSONStringBuilder.Append("{")
            objJSONStringBuilder.Append("""col1""")
            objJSONStringBuilder.Append(":")
            objJSONStringBuilder.Append("""" & objSQLDataReader("col1") & """")
            objJSONStringBuilder.Append(",")
            objJSONStringBuilder.Append("""col2""")
            objJSONStringBuilder.Append(":")
            objJSONStringBuilder.Append("""" & objSQLDataReader("col2") & """")
            objJSONStringBuilder.Append(",")
            objJSONStringBuilder.Append("""col3""")
            objJSONStringBuilder.Append(":")
            objJSONStringBuilder.Append("""" & objSQLDataReader("col3") & """")
            objJSONStringBuilder.Append("},")
        End While

        objSQLDataReader.Close()
        objSQLCommand.Connection.Close()

        objJSONStringBuilder.Remove(objJSONStringBuilder.Length - 1, 1)

        objJSONStringBuilder.Append("]")

        Return objJSONStringBuilder.ToString
    End Function
</script>

这是使用 .NET 创建 JSON 数据的首选方法吗？

我想我应该使用 asmx Web 服务并将数组转换为 json？但是我看到的所有示例都是用 C# 编写的。

Answer 1

我的机器上没有 VB，但如果您想使用 JavaScriptSerializer 类，您的项目必须面向 .NET Framework 3.5 或 .NET Framework 4.0(既不是 .NET Framework 3.5 Client Profile，也不是 .NET Framework 4.0 Client Profile)。将 System.Web.Extensions.dll 添加到引用中。

C#中的一个例子是:

public String Index()
{
    Object[] myArray = new Object[3];

    myArray[0] = new { col1 = "foo", col2 = "bar" };
    myArray[1] = new { col1 = "fizz", col2 = "buzz" };
    myArray[2] = new { col1 = "fizz", col2 = "buzz" };

    JavaScriptSerializer serializer = new JavaScriptSerializer();
    return serializer.Serialize(myArray);
}

这个函数的输出是:

[{"col1":"foo","col2":"bar"},{"col1":"fizz","col2":"buzz"},{"col1":"fizz","col2":"buzz"}]

将其转换为 VB 应该很容易。

更新: VB版本:

Function get_json() As String
    Dim myArray(2) As Object

    myArray(0) = New With {Key .col1 = "foo", .col2 = "bar"}
    myArray(1) = New With {Key .col1 = "fizz", .col2 = "buzz"}
    myArray(2) = New With {Key .col1 = "fizz", .col2 = "buzz"}

    Dim serializer As New JavaScriptSerializer()
    Return serializer.Serialize(myArray)
End Function

相同的输出，只是不要忘记导入 System.Web.Script.Serialization .