Question

我想将数据表格式的wcf rest服务返回到c＃表单，但是在将datatable表单服务器返回给客户端时会出现错误。

无法从传输连接读取数据：远程主机强行关闭现有连接。

Answer 1

也许，问题是，数据表的大小太大了。序列化数据表非常复杂，因此响应长度或深度可能会溢出。您可以尝试配置它。

但我的建议是：不要通过网络服务回复数据表:)你不应该知道，谁在另一边听。

Answer 2

我已经解决了这个问题。当我们返回数据表格式wcf rest Services时，数据表会出现序列化问题。

           to avoid this problem convert datatable in to json stirg,and return this string to client side.
               on the client side convert this string to datatable.

服务器端代码：

       public string GetAssetRegisterDataTableBySp(ParameterDto parameters)
    {
        string jsonString="";
        string query = string.Format("SELECT * FROM ReportDisplaySetting where Display= 'true'");
        var DisplayColumnSetting = repositoryReportDisplaySetting.ExecuteRawQuery<ReportDisplaySetting>(query).ToList();
        List<string> selectedColumn = DisplayColumnSetting.Select(C => C.ColumnName).ToList();
        string columnOfString = (string.Join(",", selectedColumn.Select(x => x.ToString()).ToArray()));

        List<string> locationIds = new List<string>();
        if (parameters.locationId == 0)
        {
            locationIds = repository.All<CompanyLocationMaster>().AsEnumerable().Where(x => x.CompanyID == parameters.companyId && x.IsActive == true).Select(x => x.LocationID.ToString()).ToList();
        }
        string locationString = "";
        if (locationIds.Count() > 0)
        {
            locationString = string.Join(",", locationIds.ToArray());
        }
        else
        {
            locationString = parameters.locationId.ToString();
        }
        var report = new AssetrakRepository<AssetRegisterReport>();
        DataTable taggingReport = report.GetAssetRegisterReportBySP(parameters.companyId, locationString, columnOfString);
        string strColumns = columnOfString;
        var JSONString = new StringBuilder();
        if (taggingReport.Rows.Count > 0)
        {
            JSONString.Append("[");
            for (int i = 0; i < taggingReport.Rows.Count; i++)
            {
                JSONString.Append("{");
                for (int j = 0; j < taggingReport.Columns.Count; j++)
                {
                    if (j < taggingReport.Columns.Count - 1)
                    {
                        JSONString.Append("\"" + taggingReport.Columns[j].ColumnName.ToString() + "\":" + "\"" + taggingReport.Rows[i][j].ToString().Replace(","," ") + "\",");
                    }
                    else if (j == taggingReport.Columns.Count - 1)
                    {
                        JSONString.Append("\"" + taggingReport.Columns[j].ColumnName.ToString() + "\":" + "\"" + taggingReport.Rows[i][j].ToString().Replace(",", " ") + "\"");
                    }
                }
                if (i == taggingReport.Rows.Count - 1)
                {
                    JSONString.Append("}");
                }
                else
                {
                    JSONString.Append("},");
                }
            }
            JSONString.Append("]");

        }
        jsonString=JSONString.ToString();


        return jsonString;
    }

客户端代码：

        DataTable dt = ConvertJSONToDataTable(jsonString);


       protected DataTable ConvertJSONToDataTable(string jsonString)
    {
        DataTable dt = new DataTable();
        //strip out bad characters
        string[] jsonParts = Regex.Split(jsonString.Replace("[", "").Replace("]", ""), "},{");

        //hold column names
        List<string> dtColumns = new List<string>();

        //get columns
        foreach (string jp in jsonParts)
        {
            //only loop thru once to get column names
            string[] propData = Regex.Split(jp.Replace("{", "").Replace("}", ""), ",");
            foreach (string rowData in propData)
            {
                try
                {
                    int idx = rowData.IndexOf(":");
                    string n = rowData.Substring(0, idx - 1);
                    string v = rowData.Substring(idx + 1);
                    if (!dtColumns.Contains(n))
                    {
                        dtColumns.Add(n.Replace("\"", ""));
                    }
                }
                catch (Exception ex)
                {
                    throw new Exception(string.Format("Error Parsing Column Name : {0}", rowData));
                }

            }
            break; // TODO: might not be correct. Was : Exit For
        }

        //build dt
        foreach (string c in dtColumns)
        {
            dt.Columns.Add(c);
        }
        //get table data
        foreach (string jp in jsonParts)
        {
            string[] propData = Regex.Split(jp.Replace("{", "").Replace("}", ""), ",");
            DataRow nr = dt.NewRow();
            foreach (string rowData in propData)
            {
                try
                {
                    int idx = rowData.IndexOf(":");
                    string n = rowData.Substring(0, idx - 1).Replace("\"", "");
                    string v = rowData.Substring(idx + 1).Replace("\"", "");
                    nr[n] = v;
                }
                catch (Exception ex)
                {
                    continue;
                }

            }
            dt.Rows.Add(nr);
        }
        return dt;
    }

Answer 3

以下是针对您的问题的解决方案，请参阅此博客并按照以下步骤操作我遇到的类似问题Remote Host Connectivity以及返回数据表的示例代码段。

[WebMethod]
    public DataTable GetBankdtls(string pm_Action, string pm_bankid, string pm_name, string pm_Accno, string pm_branch, string pm_VidStr)
    {
        MySqlParameter[] param = new MySqlParameter[6];
        DataTable dt = new DataTable("Bank");
        cn = new MySqlConnection(conn);
        try
        {
            string query = "DML1_getbank_Sp";
            cmd = new MySqlCommand(query, cn);
            cmd.CommandType = System.Data.CommandType.StoredProcedure;
            cmd.CommandTimeout = 120;
            cmd.Parameters.AddWithValue("pm_Action", pm_Action);
            cmd.Parameters.AddWithValue("pm_bankid", pm_bankid);
            cmd.Parameters.AddWithValue("pm_name", pm_name);
            cmd.Parameters.AddWithValue("pm_Accno", pm_Accno);
            cmd.Parameters.AddWithValue("pm_branch", pm_branch);
            cmd.Parameters.AddWithValue("pm_VidStr", pm_VidStr);               
            cn.Open();
            da.SelectCommand = cmd;
            da.Fill(dt);
            return dt;
        }
        catch (MySqlException ex)
        {
            throw ex;
        }
        finally
        {
            cmd.Connection.Close();
            cn.Close();
        }
    }

并确保您的连接应该打开，最后应该关闭。

如何返回数据表格式wcf休息服务？

3 个答案: