Question

我需要用两个excel文件填充两个数据表。这些文件可以是逗号分隔值文件（.csv），也可以是Excel文档（.xlsx）文件。我使用函数将.csv转换为数据表：

public DataTable GetDataTableFromCsv(string path)
{
    DataTable dataTable = new DataTable();
    String[] values;

    values = File.ReadAllLines(path);

    string[] csvRows = System.IO.File.ReadAllLines(path);
    string[] headers = csvRows[0].Split(',');

    // Adding columns name
    foreach (var item in headers)
        dataTable.Columns.Add(new DataColumn(item));

    string[] fields = null;

    foreach (string csvRow in csvRows)
    {
        fields = csvRow.Split(',');
        DataRow row = dataTable.NewRow();
        row.ItemArray = fields;
        dataTable.Rows.Add(row);
    }
    return dataTable;
}

当我尝试将两个数据表与：

进行比较时，会出现问题

ieDiff = dt1.AsEnumerable().Except(dt2.AsEnumerable(), DataRowComparer.Default);

我的.xlsx文件获取的第一个数据表包含正确的值，而.csv文件获取的第二个数据表包含正确的值，但有一些额外的引号。

ex：

dt1.Rows [10]（来自.csv的数据表）将包含：

项目1
项目2
“”
“项目4”

dt2.Rows [10]（来自.xlsx的数据表）将包含：

项目1
项目2
项目4

我知道我可以修剪所有这些，但肯定有更好的方法来执行此操作吗？

Answer 1

最简单的答案是你在问题中提到的修剪引号字符的答案。

我的测试代码：

var test = new[] { "Item1", "Item2", "\".\"", "\"Item4\"" };
foreach (var s in test)
{
    textBox1.AppendTextAddNewLine(s.Trim('"'));
}

结果输出：

Item1
Item2
.
Item4

Answer 2

下面我写了五个方法，将Csv文件转换为DataTable。

它们的设计考虑了可选的引号（例如＆＃34;符号），并且在不使用其他库的情况下尽可能多样化：

    public static DataTable GetDataTabletFromCSVFile(string filePath, bool isHeadings)
    {
        DataTable MethodResult = null;
        try
        {
            using (TextFieldParser TextFieldParser = new TextFieldParser(filePath))
            {
                if (isHeadings)
                {
                    MethodResult = GetDataTableFromTextFieldParser(TextFieldParser);

                }
                else
                {
                    MethodResult = GetDataTableFromTextFieldParserNoHeadings(TextFieldParser);

                }

            }

        }
        catch (Exception ex)
        {
            ex.HandleException();
        }
        return MethodResult;
    }

    public static DataTable GetDataTableFromCsvString(string csvBody, bool isHeadings)
    {
        DataTable MethodResult = null;
        try
        {
            MemoryStream MemoryStream = new MemoryStream();


            StreamWriter StreamWriter = new StreamWriter(MemoryStream);

            StreamWriter.Write(csvBody);

            StreamWriter.Flush();


            MemoryStream.Position = 0;


            using (TextFieldParser TextFieldParser = new TextFieldParser(MemoryStream))
            {
                if (isHeadings)
                {
                    MethodResult = GetDataTableFromTextFieldParser(TextFieldParser);

                }
                else
                {
                    MethodResult = GetDataTableFromTextFieldParserNoHeadings(TextFieldParser);

                }

            }

        }
        catch (Exception ex)
        {
            ex.HandleException();
        }
        return MethodResult;
    }

    public static DataTable GetDataTableFromRemoteCsv(string url, bool isHeadings)
    {
        DataTable MethodResult = null;
        try
        {
            HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
            HttpWebResponse httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();

            StreamReader StreamReader = new StreamReader(httpWebResponse.GetResponseStream());

            using (TextFieldParser TextFieldParser = new TextFieldParser(StreamReader))
            {
                if (isHeadings)
                {
                    MethodResult = GetDataTableFromTextFieldParser(TextFieldParser);

                }
                else
                {
                    MethodResult = GetDataTableFromTextFieldParserNoHeadings(TextFieldParser);

                }

            }

        }
        catch (Exception ex)
        {
            ex.HandleException();
        }
        return MethodResult;
    }


    private static DataTable GetDataTableFromTextFieldParser(TextFieldParser textFieldParser)
    {
        DataTable MethodResult = null;
        try
        {
            textFieldParser.SetDelimiters(new string[] { "," });

            textFieldParser.HasFieldsEnclosedInQuotes = true;


            string[] ColumnFields = textFieldParser.ReadFields();

            DataTable dt = new DataTable();

            foreach (string ColumnField in ColumnFields)
            {
                DataColumn DataColumn = new DataColumn(ColumnField);

                DataColumn.AllowDBNull = true;

                dt.Columns.Add(DataColumn);

            }


            while (!textFieldParser.EndOfData)
            {
                string[] Fields = textFieldParser.ReadFields();


                for (int i = 0; i < Fields.Length; i++)
                {
                    if (Fields[i] == "")
                    {
                        Fields[i] = null;

                    }

                }

                dt.Rows.Add(Fields);

            }

            MethodResult = dt;

        }
        catch (Exception ex)
        {
            ex.HandleException();
        }
        return MethodResult;
    }

    private static DataTable GetDataTableFromTextFieldParserNoHeadings(TextFieldParser textFieldParser)
    {
        DataTable MethodResult = null;
        try
        {
            textFieldParser.SetDelimiters(new string[] { "," });

            textFieldParser.HasFieldsEnclosedInQuotes = true;

            bool FirstPass = true;

            DataTable dt = new DataTable();

            while (!textFieldParser.EndOfData)
            {
                string[] Fields = textFieldParser.ReadFields();

                if(FirstPass)
                {
                    for (int i = 0; i < Fields.Length; i++)
                    {
                        DataColumn DataColumn = new DataColumn("Column " + i);

                        DataColumn.AllowDBNull = true;

                        dt.Columns.Add(DataColumn);

                    }

                    FirstPass = false;

                }

                for (int i = 0; i < Fields.Length; i++)
                {
                    if (Fields[i] == "")
                    {
                        Fields[i] = null;

                    }

                }

                dt.Rows.Add(Fields);

            }

            MethodResult = dt;

        }
        catch (Exception ex)
        {
            ex.HandleException();
        }
        return MethodResult;
    }

如果像我一样，您从报告服务中保存，那么您应该像这样使用它：

    Warning[] warnings;
    string[] streamids;
    string mimeType;
    string encoding;
    string filenameExtension;

    byte[] bytes = rvMain.ServerReport.Render("csv", null, out mimeType, out encoding, out filenameExtension, out streamids, out warnings);

    string CsvBody = System.Text.Encoding.UTF8.GetString(bytes);

    DataTable dt = GetDataTableFromCsvString(CsvBody,true);

否则，您只需要：

    bool IsHeadings = true; //Does the data include a heading row?

    DataTable dt = GetDataTableFromCsvString(CsvBody, IsHeadings);

或直接从csv文件中使用

    bool IsHeadings = true; //Does the data include a heading row?

    DataTable dt = GetDataTabletFromCsvFile(FilePath, IsHeadings)

或者使用远程存储的csv文件

    bool IsHeadings = true; //Does the data include a heading row?

    DataTable dt = GetDataTabletFromRemoteCsv(Url, IsHeadings)

将.csv转换为datatable时的额外引号

2 个答案: