以区域设置独立方式读取Excel文件

Question

我使用以下代码从各种Excel文件中读取数据:

    // IMEX=1 - to force strings on mixed data
    // HDR=NO - to process all the available data
    // Locale 1033 is en-US. This was my first attempt to force en-US locale.
    string connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Locale Identifier=1033;Extended Properties=\"{1};READONLY=TRUE;HDR=NO;IMEX=1;\"";

    // source type according to the
    // http://www.microsoft.com/en-us/download/details.aspx?id=13255

    // try determining from extension
    bool isOldFormat =
            Path.GetExtension(sourceExcel).Equals(".xls", StringComparison.OrdinalIgnoreCase);

    bool isBinary =
            Path.GetExtension(sourceExcel).Equals(".xlsb", StringComparison.OrdinalIgnoreCase);

    string sourceType = isOldFormat ? "Excel 8.0" : "Excel 12.0";

    if (!isOldFormat)
        sourceType += " Xml"; // for some reason the new binary xlsb files also need Xml

    connectionString = string.Format(connectionString, sourceExcel, sourceType);

    // this was my second attempt to force Excel to use US culture
    var oldCulture = Thread.CurrentThread.CurrentCulture;
    Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture("en-US");

    var dt = new DataTable();
    try
    {
        using (var con = new OleDbConnection(connectionString))
        {
            con.Open();

            // get all the available sheets
            using (DataTable dataSet = con.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null))
            {
                // this was my third attempt to force Excel to use US culture
                dataSet.Locale = CultureInfo.CreateSpecificCulture("en-US");
                // get the sheet name in the file (will throw if out of range)
                string workSheetName = dataSet.Rows[worksheetIndex]["TABLE_NAME"].ToString();//.Trim(new[] { '$' }).Replace("'", "");

                string sql = String.Format("select * from [{0}]", workSheetName);

                var da = new OleDbDataAdapter(sql, con);
                // this was my fourth attempt to force Excel to use US culture
                dt.Locale = CultureInfo.CreateSpecificCulture("en-US");
                da.Fill(dt);
            }

            con.Close();
        }

如你所见,我非常绝望,试图在导入数据时强制Excel使用en-US兼容的语言环境.我需要这个,因为我的代码可能在具有各种语言环境的服务器上执行,但数据需要一些额外的处理,这些处理假定传入的数据是en-US/neutral语言环境.

我也试过CultureInfo.InvariantCulture而不是CultureInfo.CreateSpecificCulture("en-US").

无论我如何尝试,当服务器区域设置设置为使用.千,位分隔符和小数分隔符的其他区域设置时,我的结果会出错dt DataTable.

要比较货币值的结果 - £200000.00:

当服务器区域设置对应于美国语言环境时,我得到 "-£200,000.00"

当服务器区域设置对应于拉脱维亚语区域设置时,我得到了 "-£200 000,00"

我甚至无法使用当前的数字分隔符对数据进行后处理Thread.CurrentThread.CurrentCulture,因为OleDb似乎完全忽略了它.

OleDb从哪里获得当前的文化？何我告诉OleDbConnection或Microsoft.ACE.OLEDB.12.0提供商我需要根据en-US或Invariant文化格式化的数据？

Answer 1

经过大量的试验和错误以及阅读这篇过时的文章后 http://support.microsoft.com/default.aspx?scid=KB;EN-US;Q320744 我发现当前版本的OLEDB默认似乎是在使用文化来自HKEY_CURRENT_USER\Control Panel\International.不幸的是,我没有找到如何SetVarConversionLocaleSetting从我的C#代码调用该函数来强制OLEDB使用当前的线程文化,所以我采用了原则 - 如果我不能为我的代码调整OLEDB,那么我将调整我的代码为与OLEDB文化兼容.在完成它之后,我可以将所有数据转换为不变文化.

但是有一个棘手的部分.您不能只从中获取小数分隔符HKEY_CURRENT_USER\Control Panel\International,因为OLEDB忽略数字格式的用户自定义设置.OLEDB仅采用该文化的默认预设值.所以我必须做以下事情:

var oldCulture = Thread.CurrentThread.CurrentCulture;

using (RegistryKey international = 
        Registry.CurrentUser.OpenSubKey("Control Panel\\International", false))
{
    string userDefaultCulture = international.GetValue("LocaleName").ToString();
    // notice: although the user might have customized his decimal/thousand separators,
    // still OLEDB ignores these customizations. That is why I create a culture with default settings.
    cultureToNormalize = new CultureInfo(userDefaultCulture, false);
}

// force both OLEDB and current thread cultures to match for the next ToString() etc. conversions in my function
Thread.CurrentThread.CurrentCulture = cultureToNormalize;

string decSep = cultureToNormalize.NumberFormat.NumberDecimalSeparator;
string groupSep = cultureToNormalize.NumberFormat.NumberGroupSeparator;

现在我可以根据需要处理数据,而且我可以安全地调用ToString() - OLEDB和.NET字符串化数字和货币的文化将匹配.而且,为了成为一个好孩子,我在功能结束时恢复了以前的文化.

如果有人有更好的解决方案,我将非常感激.但是现在我会保持原样 - 我所有的单元测试现在都是绿色的.