获取错误（生成 XML 文档时出错。）在 asp.net 的 extjs 中从服务器端获取数据

Posted 2023-02-26

【中文标题】获取错误（生成 XML 文档时出错。）在 asp.net 的 extjs 中从服务器端获取数据

【英文标题】：getting Error(There was an error generating the XML document.) fetch data from server side in extjs in asp.net

【发布时间】：2012-10-19 07:43:09

【问题描述】：

我正在使用 Extjs 4.1 和 asp.net 我正在尝试从数据库中填充网格面板，但出现错误。我正在使用网络服务来获取数据。

错误：

System.InvalidOperationException: There was an error generating the XML document. ---> System.InvalidOperationException: Cannot serialize the DataTable. DataTable name is not set.
   at System.Data.DataTable.WriteXmlSchema(XmlWriter writer, Boolean writeHierarchy)
   at System.Data.DataTable.System.Xml.Serialization.IXmlSerializable.WriteXml(XmlWriter writer)
   at System.Xml.Serialization.XmlSerializationWriter.WriteSerializable(IXmlSerializable serializable, String name, String ns, Boolean isNullable, Boolean wrapped)
   at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationWriter1.Write2_DataTable(Object o)
   at Microsoft.Xml.Serialization.GeneratedAssembly.DataTableSerializer.Serialize(Object objectToSerialize, XmlSerializationWriter writer)
   at System.Xml.Serialization.XmlSerializer.Serialize(XmlWriter xmlWriter, Object o, XmlSerializerNamespaces namespaces, String encodingStyle, String id)
   --- End of inner exception stack trace ---
   at System.Xml.Serialization.XmlSerializer.Serialize(XmlWriter xmlWriter, Object o, XmlSerializerNamespaces namespaces, String encodingStyle, String id)
   at System.Xml.Serialization.XmlSerializer.Serialize(TextWriter textWriter, Object o, XmlSerializerNamespaces namespaces)
   at System.Xml.Serialization.XmlSerializer.Serialize(TextWriter textWriter, Object o)
   at System.Web.Services.Protocols.XmlReturnWriter.Write(HttpResponse response, Stream outputStream, Object returnValue)
   at System.Web.Services.Protocols.HttpServerProtocol.WriteReturns(Object[] returnValues, Stream outputStream)
   at System.Web.Services.Protocols.WebServiceHandler.WriteReturns(Object[] returnValues)
   at System.Web.Services.Protocols.WebServiceHandler.Invoke()

我的网络服务代码

 [WebMethod]
[ScriptMethod(ResponseFormat = ResponseFormat.Json,UseHttpGet = true, XmlSerializeString = false)]
    public DataTable displayData() 
        db obj = new db();
        return obj.getCountry();
    

从 js 文件调用 web 服务

 var store = Ext.create('Ext.data.Store', 
            pageSize: 20,
            model: 'ForumThread',
            autoLoad: true,
            proxy: 
                type: 'ajax',
                url: 'report.asmx/displayData',
                dataType: "json",
                contentType: "application/json; charset=utf-8",
                 //url: '/grid.json',
                reader:     
                root: 'data'   ,          
                    type: 'json',
                    method: "GET",
                    totalProperty: 'totalCount'
                
            
        );

即使我从 webservice [ScriptMethod(ResponseFormat = ResponseFormat.Json,UseHttpGet = true, XmlSerializeString = false)] 中删除了这一行，但仍然是同样的错误。

我没有在我的代码中使用 XMLSerializer，然后它也会给我错误，比如生成 XML 文档时出错。

【参考方案1】：

如错误提示，您需要为数据表提供名称。

dt.TableName = "我的表";

【讨论】：

正如你所说，我给出了表名，但现在我收到了类似Ext.Error: Unable to parse the JSON returned by the server: You're trying to decode an invalid JSON String: <?xml version="1.0" encoding="utf-8"?>的错误

您的服务似乎使用 XML 而不是 JSON 进行响应。类似情况见此帖：***.com/questions/5611134/…