相关疑难解决方法(0)

我目前有一个处理程序,它接受excel文件的文件路径和tabname,将文件处理成数据表,然后将表序列化为json字符串以返回.这是有效的,直到我尝试处理大文件,然后我得到一个内存不足异常.

我想如果我没有先将所有内容加载到数据表中,而是直接加载到json字符串中,它会减少内存使用量.但是,我一直无法找到如何执行此操作的任何示例.

我可以直接从OleDbConnection序列化为字符串吗？怎么样？

    public void ProcessRequest(HttpContext context)
    {
        string path = context.Request["path"];
        string tableNames = context.Request["tableNames"];

        string connectionString = string.Empty;
        if (path.EndsWith(".xls"))
        {
            connectionString = String.Format(@"Provider=Microsoft.ACE.OLEDB.12.0;
                Data Source={0};
                Extended Properties=""Excel 8.0;HDR=YES;IMEX=1""", path);
        }
        else if (path.EndsWith(".xlsx"))
        {
            connectionString = String.Format(@"Provider=Microsoft.ACE.OLEDB.12.0;
                Data Source={0};
                Extended Properties=""Excel 12.0 Xml;HDR=YES;IMEX=1""", path);
        }
        DbProviderFactory factory = DbProviderFactories.GetFactory("System.Data.OleDb");

        DbDataAdapter adapter = factory.CreateDataAdapter();
        OleDbConnection conn = new OleDbConnection(connectionString);
        conn.Open();

        DataTable tmp = new DataTable();

        DbCommand selectCommand = factory.CreateCommand();

        selectCommand.CommandText = String.Format("SELECT * FROM [{0}]", tableNames);
        selectCommand.Connection = …