【C#】CsvHelper 读写CSV文件

// 版权所有 2009-2022 Josh Close
// 此文件是 CsvHelper 的一部分，在 MS-PL 和 Apache 2.0 下获得双重许可。
// 有关详细信息，请参阅 LICENSE.txt 或访问 http://www.opensource.org/licenses/ms-pl.html 对于 MS-PL 和 http://opensource.org/licenses/Apache-2.0 对于 Apache 2.0。
// https://github.com/JoshClose/CsvHelper
using System;
using System.Collections.Generic;
using System.Data;
using System.Globalization;
using System.IO;
using System.Text;
using CsvHelper.Configuration;
using CsvHelper.Tests.Mocks;
using CsvHelper.TypeConversion;
using Xunit;namespace CsvHelper.Tests.DataTableTests
{public class CsvDataReaderTests{[Fact]public void GetValuesTest(){var s = new StringBuilder();s.AppendLine("Boolean,Byte,Bytes,Char,Chars,DateTime,Decimal,Double,Float,Guid,Short,Int,Long,Null");s.AppendLine("true,1,0x0102,a,ab,1/1/2019,1.23,4.56,7.89,eca0c8c6-9a2a-4e6c-8599-3561abda13f1,1,2,3,null");using (var reader = new StringReader(s.ToString()))using (var csv = new CsvReader(reader, CultureInfo.InvariantCulture)){csv.Context.TypeConverterOptionsCache.GetOptions<string>().NullValues.Add("null");var dataReader = new CsvDataReader(csv);dataReader.Read();Assert.True(dataReader.GetBoolean(0));Assert.Equal(1, dataReader.GetByte(1));byte[] byteBuffer = new byte[2];dataReader.GetBytes(2, 0, byteBuffer, 0, byteBuffer.Length);Assert.Equal(0x1, byteBuffer[0]);Assert.Equal(0x2, byteBuffer[1]);Assert.Equal('a', dataReader.GetChar(3));char[] charBuffer = new char[2];dataReader.GetChars(4, 0, charBuffer, 0, charBuffer.Length);Assert.Equal('a', charBuffer[0]);Assert.Equal('b', charBuffer[1]);Assert.Null(dataReader.GetData(0));Assert.Equal(DateTime.Parse("1/1/2019"), dataReader.GetDateTime(5));Assert.Equal(typeof(string).Name, dataReader.GetDataTypeName(0));Assert.Equal(1.23m, dataReader.GetDecimal(6));Assert.Equal(4.56d, dataReader.GetDouble(7));Assert.Equal(typeof(string), dataReader.GetFieldType(0));Assert.Equal(7.89f, dataReader.GetFloat(8));Assert.Equal(Guid.Parse("eca0c8c6-9a2a-4e6c-8599-3561abda13f1"), dataReader.GetGuid(9));Assert.Equal(1, dataReader.GetInt16(10));Assert.Equal(2, dataReader.GetInt32(11));Assert.Equal(3, dataReader.GetInt64(12));Assert.Equal("Boolean", dataReader.GetName(0)); Assert.Equal(0, dataReader.GetOrdinal("Boolean"));//返回字段的索引Assert.Equal("true", dataReader.GetString(0));Assert.Equal("true", dataReader.GetValue(0));var objectBuffer = new object[14];dataReader.GetValues(objectBuffer);Assert.Equal("true", objectBuffer[0]);Assert.Equal(DBNull.Value, objectBuffer[13]);Assert.True(dataReader.IsDBNull(13));}}[Fact]public void GetSchemaTableTest(){var s = new StringBuilder();s.AppendLine("Id,Name");s.AppendLine("1,one");s.AppendLine("2,two");using (var reader = new StringReader(s.ToString()))using (var csv = new CsvReader(reader, CultureInfo.InvariantCulture)){var dataReader = new CsvDataReader(csv);var schemaTable = dataReader.GetSchemaTable();Assert.Equal(25, schemaTable.Columns.Count);Assert.Equal(2, schemaTable.Rows.Count);}}[Fact]public void DataTableLoadTest(){var s = new StringBuilder();s.AppendLine("Id,Name");s.AppendLine("1,one");s.AppendLine("2,two");using (var reader = new StringReader(s.ToString()))using (var csv = new CsvReader(reader, CultureInfo.InvariantCulture)){var dataReader = new CsvDataReader(csv);var dataTable = new DataTable();dataTable.Columns.Add("Id", typeof(int));dataTable.Columns.Add("Name", typeof(string));dataTable.Load(dataReader);Assert.Equal(2, dataTable.Rows.Count);Assert.Equal(1, dataTable.Rows[0]["Id"]);Assert.Equal("one", dataTable.Rows[0]["Name"]);Assert.Equal(2, dataTable.Rows[1]["Id"]);Assert.Equal("two", dataTable.Rows[1]["Name"]);}}[Fact]public void DataTableLoadHeaderAndRowsHaveDifferentLengthTest(){var s = new StringBuilder();s.AppendLine("Id,Name");s.AppendLine("1,one,a");s.AppendLine("2,two,b");using (var reader = new StringReader(s.ToString()))using (var csv = new CsvReader(reader, CultureInfo.InvariantCulture)){var dataReader = new CsvDataReader(csv);var dataTable = new DataTable();dataTable.Columns.Add("Id", typeof(int));dataTable.Columns.Add("Name", typeof(string));dataTable.Load(dataReader);Assert.Equal(2, dataTable.Rows.Count);Assert.Equal(1, dataTable.Rows[0]["Id"]);Assert.Equal("one", dataTable.Rows[0]["Name"]);Assert.Equal(2, dataTable.Rows[1]["Id"]);Assert.Equal("two", dataTable.Rows[1]["Name"]);}}[Fact]public void DataTableLoadNoHeaderTest(){var config = new CsvConfiguration(CultureInfo.InvariantCulture){HasHeaderRecord = false,};var s = new StringBuilder();s.AppendLine("1,one");s.AppendLine("2,two");using (var reader = new StringReader(s.ToString()))using (var csv = new CsvReader(reader, config)){var dataReader = new CsvDataReader(csv);var dataTable = new DataTable();dataTable.Load(dataReader);Assert.Equal(0, dataTable.Rows.Count);}}[Fact]public void ReadWithNoHeaderTest(){var config = new CsvConfiguration(CultureInfo.InvariantCulture){HasHeaderRecord = false,};var s = new StringBuilder();s.AppendLine("1,one");s.AppendLine("2,two");using (var reader = new StringReader(s.ToString()))using (var csv = new CsvReader(reader, config)){var dataReader = new CsvDataReader(csv);dataReader.Read();Assert.Equal(1, dataReader.GetInt32(0));Assert.Equal("one", dataReader.GetString(1));dataReader.Read();Assert.Equal(2, dataReader.GetInt32(0));Assert.Equal("two", dataReader.GetString(1));}}[Fact]public void IsNullTest(){var config = new CsvConfiguration(CultureInfo.InvariantCulture){HasHeaderRecord = false,};var s = new StringBuilder();s.AppendLine(",null");using (var reader = new StringReader(s.ToString()))using (var csv = new CsvReader(reader, config)){csv.Context.TypeConverterOptionsCache.GetOptions<string>().NullValues.Add("null");var dataReader = new CsvDataReader(csv);Assert.False(dataReader.IsDBNull(0));Assert.True(dataReader.IsDBNull(1));}}[Fact]public void DbNullTest(){var config = new CsvConfiguration(CultureInfo.InvariantCulture){HasHeaderRecord = false,};var s = new StringBuilder();s.AppendLine(",null");using (var reader = new StringReader(s.ToString()))using (var csv = new CsvReader(reader, config)){csv.Context.TypeConverterOptionsCache.GetOptions<string>().NullValues.Add("null");var dataReader = new CsvDataReader(csv);Assert.Equal(string.Empty, dataReader.GetValue(0));Assert.Equal(DBNull.Value, dataReader.GetValue(1));var values = new object[2];dataReader.GetValues(values);Assert.Equal(string.Empty, values[0]);Assert.Equal(DBNull.Value, values[1]);}}[Fact]public void GetOrdinalCaseInsensitiveTest(){var parser = new ParserMock{{ "Id", "Name" },{ "1", "one" },null,};using (var csv = new CsvReader(parser)){using (var dr = new CsvDataReader(csv)){var ordinal = dr.GetOrdinal("name");Assert.Equal(1, ordinal);}}}[Fact]public void GetOrdinalMissingTest(){var parser = new ParserMock{{ "Id", "Name" },{ "1", "one" },null,};using (var csv = new CsvReader(parser)){using (var dr = new CsvDataReader(csv)){Assert.Throws<IndexOutOfRangeException>(() =>{dr.GetOrdinal("Foo");});}}}[Fact]public void DataTableLoadEmptyTest(){var config = new CsvConfiguration(CultureInfo.InvariantCulture){HasHeaderRecord = false,};using (var reader = new StringReader(string.Empty))using (var csv = new CsvReader(reader, config)){var dataReader = new CsvDataReader(csv);Assert.Equal(0, dataReader.FieldCount);}}[Fact]public void DataTableNullableValueTypeTest(){var config = new CsvConfiguration(CultureInfo.InvariantCulture){};var parser = new ParserMock(config){{ "Id", "Name", "DateTime" },{ "1", "one", DateTime.Now.ToString() },};using (var csv = new CsvReader(parser))using (var dr = new CsvDataReader(csv)){csv.Context.TypeConverterOptionsCache.GetOptions<string>().NullValues.Add("");var table = new DataTable();table.Columns.Add("Id", typeof(int));table.Columns.Add("Name", typeof(string));var column = table.Columns.Add("DateTime", typeof(DateTime));column.AllowDBNull = true;table.Load(dr);}}}
}

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