MiniExcel/README.zh-CN.md
2021-07-30 08:45:26 +08:00

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简介

MiniExcel简单、高效避免OOM的.NET处理Excel查、写、填充数据工具。

目前主流框架大多需要将数据全载入到内存方便操作但这会导致内存消耗问题MiniExcel 尝试以 Stream 角度写底层算法逻辑能让原本1000多MB占用降低到几MB避免内存不够情况。

image

特点

  • 低内存耗用避免OOM(out of memoery)、频繁 Full GC 情况
  • 支持即时操作每行数据
  • 兼具搭配 LINQ 延迟查询特性,能办到低消耗、快速分页等复杂查询
  • 轻量,不需要安装 Microsoft Office、COM+DLL小于150KB
  • 简便操作的 API 风格

快速开始

安装

请查看 NuGet

更新日志

请查看 Release Notes

TODO

请查看 TODO

性能比较、测试

Benchmarks 逻辑可以在 MiniExcel.Benchmarks 查看或是提交 PR运行指令

dotnet run -p .\benchmarks\MiniExcel.Benchmarks\ -c Release -f netcoreapp3.1 -- -f * --join

最后一次运行规格、结果 :

BenchmarkDotNet=v0.12.1, OS=Windows 10.0.19042
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
  [Host]     : .NET Framework 4.8 (4.8.4341.0), X64 RyuJIT
  Job-ZYYABG : .NET Framework 4.8 (4.8.4341.0), X64 RyuJIT
IterationCount=3  LaunchCount=3  WarmupCount=3  

Benchmark History : Link

导入、查询 Excel 比较

逻辑 : 以 Test1,000,000x10.xlsx 做基准与主流框架做性能测试,总共 1,000,000 行 * 10 列笔 "HelloWorld",文件大小 23 MB

Library Method 最大内存耗用 平均时间
MiniExcel 'MiniExcel QueryFirst' 0.109 MB 0.0007264 sec
ExcelDataReader 'ExcelDataReader QueryFirst' 15.24 MB 10.66421 sec
MiniExcel 'MiniExcel Query' 17.3 MB 14.17933 sec
ExcelDataReader 'ExcelDataReader Query' 17.3 MB 22.56508 sec
Epplus 'Epplus QueryFirst' 1,452 MB 18.19801 sec
Epplus 'Epplus Query' 1,451 MB 23.64747 sec
OpenXmlSDK 'OpenXmlSDK Query' 1,412 MB 52.00327 sec
OpenXmlSDK 'OpenXmlSDK QueryFirst' 1,413 MB 52.34865 sec
ClosedXml 'ClosedXml QueryFirst' 2,158 MB 66.18897 sec
ClosedXml 'ClosedXml Query' 2,184 MB 191.43412 sec

导出、创建 Excel 比较

逻辑 : 创建1千万笔 "HelloWorld"

Library Method 最大内存耗用 平均时间
MiniExcel 'MiniExcel Create Xlsx' 15 MB 11.53181 sec
Epplus 'Epplus Create Xlsx' 1,204 MB 22.50971 sec
OpenXmlSdk 'OpenXmlSdk Create Xlsx' 2,621 MB 42.47399 sec
ClosedXml 'ClosedXml Create Xlsx' 7,141 MB 140.93992 sec

读 Excel

1. Query 查询 Excel 返回强型别 IEnumerable 数据 [Try it]

public class UserAccount
{
    public Guid ID { get; set; }
    public string Name { get; set; }
    public DateTime BoD { get; set; }
    public int Age { get; set; }
    public bool VIP { get; set; }
    public decimal Points { get; set; }
}

var rows = MiniExcel.Query<UserAccount>(path);

// or

using (var stream = File.OpenRead(path))
    var rows = stream.Query<UserAccount>();

image

2. Query 查询 Excel 返回Dynamic IEnumerable 数据 [Try it]

  • Key 系统预设为 A,B,C,D...Z
MiniExcel 1
Github 2

var rows = MiniExcel.Query(path).ToList();

// or 
using (var stream = File.OpenRead(path))
{
    var rows = stream.Query().ToList();
                
    Assert.Equal("MiniExcel", rows[0].A);
    Assert.Equal(1, rows[0].B);
    Assert.Equal("Github", rows[1].A);
    Assert.Equal(2, rows[1].B);
}

3. 查询数据以第一行数据当Key [Try it]

注意 : 同名以右边数据为准

Input Excel :

Column1 Column2
MiniExcel 1
Github 2

var rows = MiniExcel.Query(useHeaderRow:true).ToList();

// or

using (var stream = File.OpenRead(path))
{
    var rows = stream.Query(useHeaderRow:true).ToList();

    Assert.Equal("MiniExcel", rows[0].Column1);
    Assert.Equal(1, rows[0].Column2);
    Assert.Equal("Github", rows[1].Column1);
    Assert.Equal(2, rows[1].Column2);
}

4. Query 查询支援延迟加载(Deferred Execution)能配合LINQ First/Take/Skip办到低消耗、高效率复杂查询

举例 : 查询第一笔数据

var row = MiniExcel.Query(path).First();
Assert.Equal("HelloWorld", row.A);

// or

using (var stream = File.OpenRead(path))
{
    var row = stream.Query().First();
    Assert.Equal("HelloWorld", row.A);
}

与其他框架效率比较 :

queryfirst

5. 查询指定 Sheet 名称

MiniExcel.Query(path, sheetName: "SheetName");
//or
stream.Query(sheetName: "SheetName");

6. 查询所有 Sheet 名称跟数据

var sheetNames = MiniExcel.GetSheetNames(path);
foreach (var sheetName in sheetNames)
{
    var rows = MiniExcel.Query(path, sheetName: sheetName);
}

7. 查询所有栏(列)

var columns = MiniExcel.GetColumns(path); // e.g result : ["A","B"...]

var cnt = columns.Count;  // get column count

8. Dynamic Query 转成 IDictionary<string,object> 数据

foreach(IDictionary<string,object> row in MiniExcel.Query(path))
{
    //..
}

// or 
var rows = MiniExcel.Query(path).Cast<IDictionary<string,object>>(); 

9. Query 读 Excel 返回 DataTable

提醒 : 不建议使用因为DataTable会将数据全载入内存失去MiniExcel低内存消耗功能。

var table = MiniExcel.QueryAsDataTable(path, useHeaderRow: true);

image

10. 指定单元格开始读取数据

MiniExcel.Query(path,useHeaderRow:true,startCell:"B3")

image

11. 合并的单元格填充

注意 : 效率相对于没有使用合并填充来说差
底层原因 : OpenXml 标准将 mergeCells 放在文件最下方,导致需要遍历两次 sheetxml

	var config = new OpenXmlConfiguration()
	{
		FillMergedCells = true
	};
	var rows = MiniExcel.Query(path, configuration: config);

image

支持不固定长宽多行列填充

image

写 Excel

  1. 必须是非abstract 类别有公开无参数构造函数
  2. MiniExcel SaveAs 支援 IEnumerable参数延迟查询,除非必要请不要使用 ToList 等方法读取全部数据到内存

图片 : 是否呼叫 ToList 的内存差别

image1. 支持集合<匿名类别>或是<强型别> [Try it]

var path = Path.Combine(Path.GetTempPath(), $"{Guid.NewGuid()}.xlsx");
MiniExcel.SaveAs(path, new[] {
    new { Column1 = "MiniExcel", Column2 = 1 },
    new { Column1 = "Github", Column2 = 2}
});

2. IEnumerable<IDictionary<string, object>>

var values = new List<Dictionary<string, object>>()
{
    new Dictionary<string,object>{{ "Column1", "MiniExcel" }, { "Column2", 1 } },
    new Dictionary<string,object>{{ "Column1", "Github" }, { "Column2", 2 } }
};
MiniExcel.SaveAs(path, values);

output :

Column1 Column2
MiniExcel 1
Github 2

3. IDataReader 参数

  • 推荐使用,可以避免载入全部数据到内存
MiniExcel.SaveAs(path, reader);

image

4. Datatable

  • 不推荐使用,会将数据全载入内存
  • 优先使用 Caption 当栏位名称
var path = Path.Combine(Path.GetTempPath(), $"{Guid.NewGuid()}.xlsx");
var table = new DataTable();
{
    table.Columns.Add("Column1", typeof(string));
    table.Columns.Add("Column2", typeof(decimal));
    table.Rows.Add("MiniExcel", 1);
    table.Rows.Add("Github", 2);
}

MiniExcel.SaveAs(path, table);

5. Dapper

  • 不推荐使用,会将数据全载入内存
using (var connection = GetConnection(connectionString))
{
    var rows = connection.Query(@"select 'MiniExcel' as Column1,1 as Column2 union all select 'Github',2");
    MiniExcel.SaveAs(path, rows);
}

6. SaveAs 支持 Stream生成文件不落地 [Try it]

using (var stream = new MemoryStream()) //支持 FileStream,MemoryStream..等
{
    stream.SaveAs(values);
}

像是 API 导出 Excel

public IActionResult DownloadExcel()
{
    var values = new[] {
        new { Column1 = "MiniExcel", Column2 = 1 },
        new { Column1 = "Github", Column2 = 2}
    };

    var memoryStream = new MemoryStream();
    memoryStream.SaveAs(values);
    memoryStream.Seek(0, SeekOrigin.Begin);
    return new FileStreamResult(memoryStream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
    {
        FileDownloadName = "demo.xlsx"
    };
}

7. 创建多个工作表(Sheet)

// 1. Dictionary<string,object>
var users = new[] { new { Name = "Jack", Age = 25 }, new { Name = "Mike", Age = 44 } };
var department = new[] { new { ID = "01", Name = "HR" }, new { ID = "02", Name = "IT" } };
var sheets = new Dictionary<string, object>
{
    ["users"] = users,
    ["department"] = department
};
MiniExcel.SaveAs(path, sheets);

// 2. DataSet
var sheets = new DataSet();
sheets.Add(UsersDataTable);
sheets.Add(DepartmentDataTable);
//..
MiniExcel.SaveAs(path, sheets);

image

8. 表格样式选择

从v0.15.0版本开始预设样式改为

image

不需要样式

var config = new OpenXmlConfiguration()
{
    TableStyles = TableStyles.None
};
MiniExcel.SaveAs(path, value,configuration:config);

image

模板填充 Excel

  • 宣告方式类似 Vue 模板 {{变量名称}}, 或是集合渲染 {{集合名称.栏位名称}}
  • 集合渲染支持 IEnumerable/DataTable/DapperRow

1. 基本填充

模板:
image

最终效果:
image

代码:

// 1. By POCO
var value = new
{
    Name = "Jack",
    CreateDate = new DateTime(2021, 01, 01),
    VIP = true,
    Points = 123
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);


// 2. By Dictionary
var value = new Dictionary<string, object>()
{
    ["Name"] = "Jack",
    ["CreateDate"] = new DateTime(2021, 01, 01),
    ["VIP"] = true,
    ["Points"] = 123
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);

2. IEnumerable 数据填充

Note1: 同行从左往右以第一个 IEnumerableUse 当列表来源 (不支持同列多集合)

模板:
image

最终效果:
image

代码:

//1. By POCO
var value = new
{
    employees = new[] {
        new {name="Jack",department="HR"},
        new {name="Lisa",department="HR"},
        new {name="John",department="HR"},
        new {name="Mike",department="IT"},
        new {name="Neo",department="IT"},
        new {name="Loan",department="IT"}
    }
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);

//2. By Dictionary
var value = new Dictionary<string, object>()
{
    ["employees"] = new[] {
        new {name="Jack",department="HR"},
        new {name="Lisa",department="HR"},
        new {name="John",department="HR"},
        new {name="Mike",department="IT"},
        new {name="Neo",department="IT"},
        new {name="Loan",department="IT"}
    }
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);

3. 复杂数据填充

Note: 支持多 sheet 填充,并共用同一组参数

模板:

image

最终效果:

image

代码:

// 1. By POCO
var value = new
{
    title = "FooCompany",
    managers = new[] {
        new {name="Jack",department="HR"},
        new {name="Loan",department="IT"}
    },
    employees = new[] {
        new {name="Wade",department="HR"},
        new {name="Felix",department="HR"},
        new {name="Eric",department="IT"},
        new {name="Keaton",department="IT"}
    }
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);

// 2. By Dictionary
var value = new Dictionary<string, object>()
{
    ["title"] = "FooCompany",
    ["managers"] = new[] {
        new {name="Jack",department="HR"},
        new {name="Loan",department="IT"}
    },
    ["employees"] = new[] {
        new {name="Wade",department="HR"},
        new {name="Felix",department="HR"},
        new {name="Eric",department="IT"},
        new {name="Keaton",department="IT"}
    }
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);

4. 大数据填充效率比较

NOTE: 在 MiniExcel 使用 IEnumerable 延迟 ( 不ToList ) 可以节省内存使用

image

5. Cell 值自动类别对应

模板

image

最终效果

image

类别

public class Poco
{
    public string @string { get; set; }
    public int? @int { get; set; }
    public decimal? @decimal { get; set; }
    public double? @double { get; set; }
    public DateTime? datetime { get; set; }
    public bool? @bool { get; set; }
    public Guid? Guid { get; set; }
}

代码

var poco = new TestIEnumerableTypePoco { @string = "string", @int = 123, @decimal = decimal.Parse("123.45"), @double = (double)123.33, @datetime = new DateTime(2021, 4, 1), @bool = true, @Guid = Guid.NewGuid() };
var value = new
{
    Ts = new[] {
        poco,
        new TestIEnumerableTypePoco{},
        null,
        poco
    }
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);

6. Example : 列出 Github 专案

模板

image

最终效果

image

代码

var projects = new[]
{
    new {Name = "MiniExcel",Link="https://github.com/shps951023/MiniExcel",Star=146, CreateTime=new DateTime(2021,03,01)},
    new {Name = "HtmlTableHelper",Link="https://github.com/shps951023/HtmlTableHelper",Star=16, CreateTime=new DateTime(2020,02,01)},
    new {Name = "PocoClassGenerator",Link="https://github.com/shps951023/PocoClassGenerator",Star=16, CreateTime=new DateTime(2019,03,17)}
};
var value = new
{
    User = "ITWeiHan",
    Projects = projects,
    TotalStar = projects.Sum(s => s.Star)
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);

7. DataTable 当参数

var managers = new DataTable();
{
    managers.Columns.Add("name");
    managers.Columns.Add("department");
    managers.Rows.Add("Jack", "HR");
    managers.Rows.Add("Loan", "IT");
}
var value = new Dictionary<string, object>()
{
    ["title"] = "FooCompany",
    ["managers"] = managers,
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);

Excel 列属性 (Excel Column Attribute)

1. 指定列名称、指定第几列、是否忽略该列

Excel例子

image

代码

public class ExcelAttributeDemo
{
    [ExcelColumnName("Column1")]
    public string Test1 { get; set; }
    [ExcelColumnName("Column2")]
    public string Test2 { get; set; }
    [ExcelIgnore]
    public string Test3 { get; set; }
    [ExcelColumnIndex("I")] // 系统会自动转换"I"为第8列
    public string Test4 { get; set; } 
    public string Test5 { get; } //系统会忽略此列
    public string Test6 { get; private set; } //set非公开,系统会忽略
    [ExcelColumnIndex(3)] // 从0开始索引
    public string Test7 { get; set; }
}

var rows = MiniExcel.Query<ExcelAttributeDemo>(path).ToList();
Assert.Equal("Column1", rows[0].Test1);
Assert.Equal("Column2", rows[0].Test2);
Assert.Null(rows[0].Test3);
Assert.Equal("Test7", rows[0].Test4);
Assert.Null(rows[0].Test5);
Assert.Null(rows[0].Test6);
Assert.Equal("Test4", rows[0].Test7);

2. 自定义日期格式 (ExcelFormatAttribute)

类别

public class Dto
{
    public string Name { get; set; }

    [ExcelFormat("MMMM dd, yyyy")]
    public DateTime InDate { get; set; }
}

代码

var value = new Dto[] {
    new Issue241Dto{ Name="Jack",InDate=new DateTime(2021,01,04)},
    new Issue241Dto{ Name="Henry",InDate=new DateTime(2020,04,05)},
};
MiniExcel.SaveAs(path, value);

效果

image

Query 支持自定义格式转换

image

Excel 类别自动判断

  • MiniExcel 预设会根据文件扩展名判断是 xlsx 还是 csv但会有失准时候请自行指定。
  • Stream 类别无法判断来源于哪种 excel 请自行指定
stream.SaveAs(excelType:ExcelType.CSV);
//or
stream.SaveAs(excelType:ExcelType.XLSX);
//or
stream.Query(excelType:ExcelType.CSV);
//or
stream.Query(excelType:ExcelType.XLSX);

CSV

概念

  • 预设全以字串类型返回,预设不会转换为数字或者日期,除非有强型别定义泛型

自定分隔符

预设以 , 作为分隔符,自定义请修改 Seperator 属性

var config = new MiniExcelLibs.Csv.CsvConfiguration() 
{
    Seperator=';'
};
MiniExcel.SaveAs(path, values,configuration: config);

自定义换行符

预设以 \r\n 作为换行符,自定义请修改 NewLine 属性

var config = new MiniExcelLibs.Csv.CsvConfiguration() 
{
    NewLine='\n'
};
MiniExcel.SaveAs(path, values,configuration: config);

自定义编码

  • 预设编码为「从Byte顺序标记检测编码」(detectEncodingFromByteOrderMarks: true)
  • 有自定义编码需求,请修改 StreamReaderFunc / StreamWriterFunc 属性
// Read
var config = new MiniExcelLibs.Csv.CsvConfiguration()
{
    StreamReaderFunc = (stream) => new StreamReader(stream,Encoding.GetEncoding("gb2312"))
};
var rows = MiniExcel.Query(path, true,excelType:ExcelType.CSV,configuration: config);

// Write
var config = new MiniExcelLibs.Csv.CsvConfiguration()
{
    StreamWriterFunc = (stream) => new StreamWriter(stream, Encoding.GetEncoding("gb2312"))
};
MiniExcel.SaveAs(path, value,excelType:ExcelType.CSV, configuration: config);

异步 Async

从 v0.17.0 版本开始支持异步 (感谢isdaniel ( SHIH,BING-SIOU))

public static Task SaveAsAsync(string path, object value, bool printHeader = true, string sheetName = "Sheet1", ExcelType excelType = ExcelType.UNKNOWN, IConfiguration configuration = null)
public static Task SaveAsAsync(this Stream stream, object value, bool printHeader = true, string sheetName = "Sheet1", ExcelType excelType = ExcelType.XLSX, IConfiguration configuration = null)
public static Task<IEnumerable<dynamic>> QueryAsync(string path, bool useHeaderRow = false, string sheetName = null, ExcelType excelType = ExcelType.UNKNOWN, string startCell = "A1", IConfiguration configuration = null)
public static Task<IEnumerable<T>> QueryAsync<T>(this Stream stream, string sheetName = null, ExcelType excelType = ExcelType.UNKNOWN, string startCell = "A1", IConfiguration configuration = null) where T : class, new()    
public static Task<IEnumerable<T>> QueryAsync<T>(string path, string sheetName = null, ExcelType excelType = ExcelType.UNKNOWN, string startCell = "A1", IConfiguration configuration = null) where T : class, new() 
public static Task<IEnumerable<IDictionary<string, object>>> QueryAsync(this Stream stream, bool useHeaderRow = false, string sheetName = null, ExcelType excelType = ExcelType.UNKNOWN, string startCell = "A1", IConfiguration configuration = null)
public static Task SaveAsByTemplateAsync(this Stream stream, string templatePath, object value)
public static Task SaveAsByTemplateAsync(this Stream stream, byte[] templateBytes, object value)    
public static Task SaveAsByTemplateAsync(string path, string templatePath, object value)
public static Task SaveAsByTemplateAsync(string path, byte[] templateBytes, object value) 
public static Task<DataTable> QueryAsDataTableAsync(string path, bool useHeaderRow = true, string sheetName = null, ExcelType excelType = ExcelType.UNKNOWN, string startCell = "A1", IConfiguration configuration = null)

例子

1. SQLite & Dapper 读取大数据新增到数据库

Note : 请不要呼叫 call ToList/ToArray 等方法,这会将所有数据读到内存内

using (var connection = new SQLiteConnection(connectionString))
{
    connection.Open();
    using (var transaction = connection.BeginTransaction())
    using (var stream = File.OpenRead(path))
    {
       var rows = stream.Query();
       foreach (var row in rows)
             connection.Execute("insert into T (A,B) values (@A,@B)", new { row.A, row.B }, transaction: transaction);
       transaction.Commit();
    }
}

效能: image

2. ASP.NET Core 3.1 下载/上传 Excel Xlsx API Demo Try it

public class ApiController : Controller
{
    public IActionResult Index()
    {
        return new ContentResult
        {
            ContentType = "text/html",
            StatusCode = (int)HttpStatusCode.OK,
            Content = @"<html><body>
<a href='api/DownloadExcel'>DownloadExcel</a><br>
<a href='api/DownloadExcelFromTemplatePath'>DownloadExcelFromTemplatePath</a><br>
<a href='api/DownloadExcelFromTemplateBytes'>DownloadExcelFromTemplateBytes</a><br>
<p>Upload Excel</p>
<form method='post' enctype='multipart/form-data' action='/api/uploadexcel'>
    <input type='file' name='excel'> <br>
    <input type='submit' >
</form>
</body></html>"
        };
    }

    public IActionResult DownloadExcel()
    {
        var values = new[] {
            new { Column1 = "MiniExcel", Column2 = 1 },
            new { Column1 = "Github", Column2 = 2}
        };
        var memoryStream = new MemoryStream();
        memoryStream.SaveAs(values);
        memoryStream.Seek(0, SeekOrigin.Begin);
        return new FileStreamResult(memoryStream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
        {
            FileDownloadName = "demo.xlsx"
        };
    }

    public IActionResult DownloadExcelFromTemplatePath()
    {
        string templatePath = "TestTemplateComplex.xlsx";

        Dictionary<string, object> value = new Dictionary<string, object>()
        {
            ["title"] = "FooCompany",
            ["managers"] = new[] {
                new {name="Jack",department="HR"},
                new {name="Loan",department="IT"}
            },
            ["employees"] = new[] {
                new {name="Wade",department="HR"},
                new {name="Felix",department="HR"},
                new {name="Eric",department="IT"},
                new {name="Keaton",department="IT"}
            }
        };

        MemoryStream memoryStream = new MemoryStream();
        memoryStream.SaveAsByTemplate(templatePath, value);
        memoryStream.Seek(0, SeekOrigin.Begin);
        return new FileStreamResult(memoryStream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
        {
            FileDownloadName = "demo.xlsx"
        };
    }

    private static Dictionary<string, Byte[]> TemplateBytesCache = new Dictionary<string, byte[]>();

    static ApiController()
    {
        string templatePath = "TestTemplateComplex.xlsx";
        byte[] bytes = System.IO.File.ReadAllBytes(templatePath);
        TemplateBytesCache.Add(templatePath, bytes);
    }

    public IActionResult DownloadExcelFromTemplateBytes()
    {
        byte[] bytes = TemplateBytesCache["TestTemplateComplex.xlsx"];

        Dictionary<string, object> value = new Dictionary<string, object>()
        {
            ["title"] = "FooCompany",
            ["managers"] = new[] {
                new {name="Jack",department="HR"},
                new {name="Loan",department="IT"}
            },
            ["employees"] = new[] {
                new {name="Wade",department="HR"},
                new {name="Felix",department="HR"},
                new {name="Eric",department="IT"},
                new {name="Keaton",department="IT"}
            }
        };

        MemoryStream memoryStream = new MemoryStream();
        memoryStream.SaveAsByTemplate(bytes, value);
        memoryStream.Seek(0, SeekOrigin.Begin);
        return new FileStreamResult(memoryStream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
        {
            FileDownloadName = "demo.xlsx"
        };
    }

    public IActionResult UploadExcel(IFormFile excel)
    {
        var stream = new MemoryStream();
        excel.CopyTo(stream);

        foreach (var item in stream.Query(true))
        {
            // do your logic etc.
        }

        return Ok("File uploaded successfully");
    }
}

3. 分页查询

void Main()
{
	var rows = MiniExcel.Query(path);
	
	Console.WriteLine("==== No.1 Page ====");
	Console.WriteLine(Page(rows,pageSize:3,page:1));
	Console.WriteLine("==== No.50 Page ====");
	Console.WriteLine(Page(rows,pageSize:3,page:50));
	Console.WriteLine("==== No.5000 Page ====");
	Console.WriteLine(Page(rows,pageSize:3,page:5000));
}

public static IEnumerable<T> Page<T>(IEnumerable<T> en, int pageSize, int page)
{
	return en.Skip(page * pageSize).Take(pageSize);
}

20210419

4. WebForm不落地导出Excel

var fileName = "Demo.xlsx";
var sheetName = "Sheet1";
HttpResponse response = HttpContext.Current.Response;
response.Clear();
response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
response.AddHeader("Content-Disposition", $"attachment;filename=\"{fileName}\"");
var values = new[] {
    new { Column1 = "MiniExcel", Column2 = 1 },
    new { Column1 = "Github", Column2 = 2}
};
var memoryStream = new MemoryStream();
memoryStream.SaveAs(values, sheetName: sheetName);
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(Response.OutputStream);
response.End();

5. 动态 i18n 多国语言跟权限管理

像例子一样,建立一个方法处理 i18n 跟权限管理,并搭配 yield return 返回 IEnumerable<Dictionary<string, object>>,即可达到动态、低内存处理效果

void Main()
{
	var value = new Order[] {
		new Order(){OrderNo = "SO01",CustomerID="C001",ProductID="P001",Qty=100,Amt=500},
		new Order(){OrderNo = "SO02",CustomerID="C002",ProductID="P002",Qty=300,Amt=400},
	};

	Console.WriteLine("en-Us and Sales role");
	{
		var path = Path.GetTempPath() + Guid.NewGuid() + ".xlsx";
		var lang = "en-US";
		var role = "Sales";
		MiniExcel.SaveAs(path, GetOrders(lang, role, value));
		MiniExcel.Query(path, true).Dump();
	}

	Console.WriteLine("zh-CN and PMC role");
	{
		var path = Path.GetTempPath() + Guid.NewGuid() + ".xlsx";
		var lang = "zh-CN";
		var role = "PMC";
		MiniExcel.SaveAs(path, GetOrders(lang, role, value));
		MiniExcel.Query(path, true).Dump();
	}
}

private IEnumerable<Dictionary<string, object>> GetOrders(string lang, string role, Order[] orders)
{
	foreach (var order in orders)
	{
		var newOrder = new Dictionary<string, object>();

		if (lang == "zh-CN")
		{
			newOrder.Add("客户编号", order.CustomerID);
			newOrder.Add("订单编号", order.OrderNo);
			newOrder.Add("产品编号", order.ProductID);
			newOrder.Add("数量", order.Qty);
			if (role == "Sales")
				newOrder.Add("价格", order.Amt);
			yield return newOrder;
		}
		else if (lang == "en-US")
		{
			newOrder.Add("Customer ID", order.CustomerID);
			newOrder.Add("Order No", order.OrderNo);
			newOrder.Add("Product ID", order.ProductID);
			newOrder.Add("Quantity", order.Qty);
			if (role == "Sales")
				newOrder.Add("Amount", order.Amt);
			yield return newOrder;
		}
		else
		{
			throw new InvalidDataException($"lang {lang} wrong");
		}
	}
}

public class Order
{
	public string OrderNo { get; set; }
	public string CustomerID { get; set; }
	public decimal Qty { get; set; }
	public string ProductID { get; set; }
	public decimal Amt { get; set; }
}

image

6. CSV 转成 Xlsx

public void CsvToXlsx(string csvPath, string xlsxPath)
{
	var value = MiniExcel.Query(csvPath, true);
	MiniExcel.SaveAs(xlsxPath, value);
}

image

FAQ 常见问题

Q: Excel 表头标题名称跟 class 属性名称不一致,如何对应?

A. 请使用 ExcelColumnName 作 mapping

image

Q. 多工作表(sheet)如何导出/查询数据?

A. 使用 GetSheetNames 方法搭配 Query 的 sheetName 参数

var sheets = MiniExcel.GetSheetNames(path);
foreach (var sheet in sheets)
{
    Console.WriteLine($"sheet name : {sheet} ");
    var rows = MiniExcel.Query(path,useHeaderRow:true,sheetName:sheet);
    Console.WriteLine(rows);
}

image

Q. 查询如何映射枚举(enum)?

A. 名称一样,系统会自动映射(注意:大小写不敏感)

image

Q. 是否使用 Count 会载入全部数据到内存

不会,图片测试一百万行*十列数据,简单测试,内存最大使用 < 60MB花费13.65秒

image

Q. Query如何使用整数索引取值?

Query 预设索引为字串Key : A,B,C....,想要改为数字索引,请建立以下方法自行转换

void Main()
{
	var path = @"D:\git\MiniExcel\samples\xlsx\TestTypeMapping.xlsx";
	var rows = MiniExcel.Query(path,true);
	foreach (var r in ConvertToIntIndexRows(rows))
	{
		Console.Write($"column 0 : {r[0]} ,column 1 : {r[1]}");
		Console.WriteLine();
	}
}

private IEnumerable<Dictionary<int, object>> ConvertToIntIndexRows(IEnumerable<object> rows)
{
	ICollection<string> keys = null;
	var isFirst = true;
	foreach (IDictionary<string,object> r in rows)
	{
		if(isFirst)
		{
			keys = r.Keys;
			isFirst = false;
		}
		
		var dic = new Dictionary<int, object>();
		var index = 0;
		foreach (var key in keys)
			dic[index++] = r[key];
		yield return dic;
	}
}

Q. 导出时数组为空时生成没有标题空 Excel

因为 MiniExcel 使用类似 JSON.NET 动态从值获取类别机制简化 API 操作,没有数据就无法获取类别。可以查看 issue #133 了解。

image

局限与警告

  • 目前不支援 xls (97-2003) 或是加密文件
  • xlsm 只支持查询

参考

ExcelDataReader / ClosedXML / Dapper

感谢名单

Jetbrains

jetbrains-variant-2

感谢提供免费IDE支持此项目 (License)

Contributors