Blazor 中的 CsvHelper 将 »¿ 插入到文件的第一行第一列

Question

我正在 .net 8 中使用 Blazor 服务器。我正在尝试保存 csv 文件并使用 CsvHelper 来执行此操作。问题是附加字符被添加到第一个条目中。

我的 razor.cs 文件如下所示：

    private async Task ExportToCSV()
    {
        var myExport = new CsvExport(includeColumnSeparatorDefinitionPreamble: false, includeHeaderRow: false);

        myExport.AddRow();
        myExport["Directions"] = "Directions";
        myExport["Leg"] = "Leg";
        myExport["LegTime"] = "Leg Time";
        myExport["Trip"] = "Trip";
        myExport["TripTime"] = "Trip Time";


        foreach (var direction in LoadedDrivingDirections)
        {
            var row = new object[5]
            {
                    $"{direction.Maneuver} on {direction.Road}",
                    direction.LegDistance.ToString("0.00"),
                    TimeSpan.FromMinutes(direction.Time).ToString(@"hh\:mm"),
                    direction.DistanceAtStart.ToString("0.00"),
                    TimeSpan.FromMinutes(drivingDirectionViews.Where(w => w.Direction.Latitude == direction.Latitude).Select(s => s.TotalTime).FirstOrDefault()).ToString(@"hh\:mm")
            };

            myExport.AddRow();
            myExport["Directions"] = row[0];
            myExport["Leg"] = row[1];
            myExport["LegTime"] = row[2];
            myExport["Trip"] = row[3];
            myExport["TripTime"] = row[4];
        }

        await _js.SaveAs("ProMilesTrip.csv", myExport.ExportAsMemoryStream().ToArray());
    }

我的js函数如下：

function saveAsFile(filename, bytesBase64) {

if (navigator.msSaveBlob) {
    //Download document in Edge browser
    var data = window.atob(bytesBase64);
    var bytes = new Uint8Array(data.length);
    for (var i = 0; i < data.length; i++) {
        bytes[i] = data.charCodeAt(i);
    }
    var blob = new Blob([bytes.buffer], { type: "application/octet-stream" });
    navigator.msSaveBlob(blob, filename);
}
else {
    var link = document.createElement('a');
    link.download = filename;
    link.href = "data:application/octet-stream;base64," + bytesBase64;
    document.body.appendChild(link); // Needed for Firefox
    link.click();
    document.body.removeChild(link);
}
}

Answer 1

CSV 开头的字符似乎是字节顺序标记。

假设您正在使用jitbit/CsvExport，该方法

CsvExport.ExportAsMemoryStream(Encoding encoding = null)

有一个可选参数

Encoding encoding

：

 private readonly Encoding _defaultEncoding = Encoding.UTF8;

 public MemoryStream ExportAsMemoryStream(Encoding encoding = null)
 {
     MemoryStream ms = new MemoryStream();

     encoding = encoding ?? _defaultEncoding;

默认值，

Encoding.UTF8

：

返回一个

UTF8Encoding

对象，该对象提供 Unicode 字节顺序标记 (BOM)。

既然您不希望这样，请传入您自己的编码，并将构造函数参数

encoderShouldEmitUTF8Identifier

设置为

false

:

_js.SaveAs("ProMilesTrip.csv", 
           myExport.ExportAsMemoryStream(encoding : new UTF8Encoding(false)).ToArray());