CSharpe中的IO+NPOI+序列化

思成俊远 · 发表于 2024-6-13 20:05:12

CSharpe中的IO+NPOI+序列化

文件文件夹操作

学习一下常见的文件、文件夹的操作。
什么是IO流？
I:就是input O:就是output,故称:输入输出流
将数据读入内存或者内存输出的过程。
常见的IO流操作，一般说的是[内存]与[磁盘]之间的输入输出。
作用
持久化数据，保证数据不再丢失！
文件操作流程:打开文件、读写数据、关闭文件。
常见的文件IO操作

//这是操作文件、文件夹必备
if (!Directory.Exists(LogPath))//检测文件夹是否存在
{
}
DirectoryInfo directory = new DirectoryInfo(LogPath);//对文件夹、文件的描述对象、不存在不报错注意exists属性
Console.WriteLine($"全名称：{directory.FullName} || 创建时间:{directory.CreationTime} || 最后写入时间:{directory.LastWriteTime}");
//路径拼接，得到一个完整的路径
string filePath = Path.Combine(LogPath, "info.txt");
if (!File.Exists(filePath))
{
}
FileInfo fileInfo = new FileInfo(filePath);
Console.WriteLine($"全名称：{fileInfo.FullName} || 创建时间:{fileInfo.CreationTime} || 最后写入时间:{fileInfo.LastWriteTime}");

复制代码

常见的文件夹操作

{
if (!Directory.Exists(LogPath))
{
DirectoryInfo directoryInfo = Directory.CreateDirectory(LogPath);//一次性创建全部的子路径
Directory.Move(LogPath, LogMovePath);//移动原文件夹就不在了
Directory.Delete(LogMovePath);//删除
}
}

复制代码

常见的文件读写操作

string fileName = Path.Combine(LogPath, "log.txt");
string fileNameCopy = Path.Combine(LogPath, "logCopy.txt");
string fileNameMove = Path.Combine(LogPath, "logMove.txt");
bool isExists = File.Exists(fileName);
if (!isExists)
{
Directory.CreateDirectory(LogPath);//创建了文件夹之后，才能创建里面的文件
using (FileStream fileStream = File.Create(fileName))//打开文件流（创建文件并写入）
{
string name = "12345567778890";
byte[] bytes = Encoding.Default.GetBytes(name);
fileStream.Write(bytes, 0, bytes.Length);
fileStream.Flush();
}
using (FileStream fileStream = File.Create(fileName))//打开文件流（创建文件并写入）
{
StreamWriter sw = new StreamWriter(fileStream);
sw.WriteLine("1234567890");
sw.Flush();
}
using (StreamWriter sw = File.AppendText(fileName))//流写入器（创建/打开文件并写入）
{
string msg = "大家好，我是Richard老师！！";
sw.WriteLine(msg);
sw.Flush();
}
using (StreamWriter sw = File.AppendText(fileName))//流写入器（创建/打开文件并写入）
{
string name = "0987654321";
byte[] bytes = Encoding.Default.GetBytes(name);
sw.BaseStream.Write(bytes, 0, bytes.Length);
sw.Flush();
}
//文件的读取
foreach (string result in File.ReadAllLines(fileName))//读取文件中所有的行信息
{
Console.WriteLine(result);
}
string sResult = File.ReadAllText(fileName);
Byte[] byteContent = File.ReadAllBytes(fileName);
string sResultByte = System.Text.Encoding.UTF8.GetString(byteContent);
//建议大家不要去做多线程读取，即使要多线程读取，也要加锁，加锁----反多线程；
//你们有没有遇到过大文件Txt---10G
using (FileStream stream = File.OpenRead(fileName))//分批读取
{
int length = 5;
int result = 0;
do
{
byte[] bytes = new byte[length];
result = stream.Read(bytes, 0, 5);
for (int i = 0; i < result; i++)
{
Console.WriteLine(bytes[i].ToString());
}
}
while (length == result);
}
File.Copy(fileName, fileNameCopy);
File.Move(fileName, fileNameMove);
File.Delete(fileNameCopy);
File.Delete(fileNameMove);//尽量不要delete
}

复制代码

常见的盘符操作

{//DriveInfo
DriveInfo[] drives = DriveInfo.GetDrives();//获取当前计算机所有盘符
foreach (DriveInfo drive in drives)
{
if (drive.IsReady)
Console.WriteLine($"类型：{drive.DriveType} 卷标：{drive.VolumeLabel} 名称：{drive.Name} 总空间：{drive.TotalSize} 剩余空间：{drive.TotalFreeSpace}");
else
Console.WriteLine("类型：{drive.DriveType} is not ready");
}
}
{
Console.WriteLine(Path.GetDirectoryName(LogPath)); //返回目录名，需要注意路径末尾是否有反斜杠对结果是有影响的
Console.WriteLine(Path.GetDirectoryName(@"d:\\abc")); //将返回 d:\
Console.WriteLine(Path.GetDirectoryName(@"d:\\abc"));// 将返回 d:\abc
Console.WriteLine(Path.GetRandomFileName());//将返回随机的文件名
Console.WriteLine(Path.GetFileNameWithoutExtension("d:\\abc.txt"));// 将返回abc
Console.WriteLine(Path.GetInvalidPathChars());// 将返回禁止在路径中使用的字符
Console.WriteLine(Path.GetInvalidFileNameChars());//将返回禁止在文件名中使用的字符
Console.WriteLine(Path.Combine(LogPath, "log.txt"));//合并两个路径
}

复制代码

递归获取所有的文件

public static List<DirectoryInfo> GetAllDirectory(string rootPath)
{
if (!Directory.Exists(rootPath))
return new List<DirectoryInfo>();
List<DirectoryInfo> directoryList = new List<DirectoryInfo>();//容器
DirectoryInfo directory = new DirectoryInfo(rootPath);//root文件夹
directoryList.Add(directory);
return GetChild(directoryList, directory);
}
/// <summary>
/// 完成文件夹--子目录--放入集合
/// </summary>
/// <param name="directoryList"></param>
/// <param name="directoryCurrent"></param>
/// <returns></returns>
private static List<DirectoryInfo> GetChild(List<DirectoryInfo> directoryList, DirectoryInfo directoryCurrent)
{
var childArray = directoryCurrent.GetDirectories();
if (childArray != null && childArray.Length > 0)
{
directoryList.AddRange(childArray);
foreach (var child in childArray)
{
GetChild(directoryList, child);
}
}
return directoryList;
}

复制代码

NPOI操作Excel

NPOI背景

Apache Poi是一种流行的API，它允许程序员使用java程序创建，修改和显示MS Office文件。这由Apche软件基金会开发使用java分布式设计或修改该Microsoft Office文件的开源库，它包含类和方法对用户输入数据或文件到Ms Office文档进行解码；
NPOI是什么呢？顾名思义就是POI的.NET版本，可以通过.NET来操作Office文档。
使用NPOI

名词解释
整个Excel:工作簿
Sheet页:页签，一个工作簿客户可以包含多个Sheet页。
表格:对应一个Sheet
行、列、单元格
C#中的常规操作:
导出一个Excel:其实就是要生成一个Excel文件，Excel文件对应的文件流。
导入一个Excel:读取一个文件，读取文件流，需要从文件流中读取我们需要的各种数据，解析Excel的数据。
创建一个Excel文件:

public class ExcelOperationHelper
{
public static IWorkbook CreateExcelWorkbook(string filePath)
{
IWorkbook workbook = null;
if (filePath.EndsWith(".xls"))
{
workbook = new NPOI.HSSF.UserModel.HSSFWorkbook();
}
else if (filePath.EndsWith(".xlsx"))
{
workbook = new NPOI.XSSF.UserModel.XSSFWorkbook();
}
ISheet sheet = workbook.CreateSheet("Sheet1");
{
IRow row = sheet.CreateRow(0);
ICell cell = row.CreateCell(0);
cell.SetCellValue("学生姓名");
ICell cell1 = row.CreateCell(1);
cell1.SetCellValue("数学成绩");
ICell cell2 = row.CreateCell(2);
cell2.SetCellValue("语文成绩");
}
{
IRow row = sheet.CreateRow(1);
ICell cell = row.CreateCell(0);
cell.SetCellValue("JJ鹏");
ICell cell1 = row.CreateCell(1);
cell1.SetCellValue("100");
ICell cell2 = row.CreateCell(2);
cell2.SetCellValue("150");
}
return workbook;
}
}

复制代码

Programs.cs

IWorkbook work = ExcelOperationHelper.CreateExcelWorkbook(path);
using (FileStream file=new FileStream(path,FileMode.Create))
{
work.Write(file);
file.Close();
}

复制代码

数据实体设置

需要考虑的问题

数据写道工作簿中的哪个sheet页中
生成的Excel---考虑表头放在哪个位置
直接集合中的某一个对象来直接生成---如果对象是一个实体---实体中有多少个属性；就表示多少个列；
最终的目标:做到业务系统不需要考虑其他，只需要按照规则来给定数据即可，就可以生成Excel出来。

数据实体

public class ExcelDataResource
{
/// <summary>
/// 保存到Sheet的名称
/// </summary>
public string SheetName { get; set; }
/// <summary>
/// 标题所在行
/// </summary>
public int TitleIndex { get; set; }
/// <summary>
/// 每一个sheet的数据
/// </summary>
public List<object> SheetDataResource { get; set; }
}

复制代码

添加一个新的特性

public class TitleAttribute:Attribute
{
public string Title { get; set; }
public TitleAttribute(string title)
{
Title = title;
}
}

复制代码

用户的信息

public class UserInfo
{
[Title("用户ID")]
public int UserId { get; set; }
[Title("用户名称")]
public string UserName { get; set; }
[Title("用户年龄")]
public int UserAge { get; set; }
[Title("用户类型")]
public string UserType { get; set; }
[Title("描述")]
public string Description { get; set; }
}
}

复制代码

根据固定格式生成IWorkBook

生成我们需要的excel的数据

static List<ExcelDataResource> GetExcelDataList()
{
List<object> objlist = new List<object>();
for (int i = 0; i < 100; i++)
{
objlist.Add(new UserInfo()
{
UserId = i + 1,
UserName = $"名称-{i}",
UserAge = i + i + 1,
UserType = i + 1,
Description = $"描述_描述_描述_描述_描述_描述_描述_描述_描述_描述_{i}"
});
}
List<object> Classobjlist = new List<object>();
for (int i = 0; i < 200; i++)
{
Classobjlist.Add(new ClassInfo()
{
UserId = i + 1,
UserName = $"名称-{i}",
Age = i + i + 1,
UserType = i + 1,
Description1 = $"描述_描述_描述_描述_描述_描述_描述_描述_描述_描述_{i}",
Description2 = $"描述_描述_描述_描述_描述_描述_描述_描述_描述_描述_{i}",
Description3 = $"描述_描述_描述_描述_描述_描述_描述_描述_描述_描述_{i}",
Description4 = $"描述_描述_描述_描述_描述_描述_描述_描述_描述_描述_{i}"
});
}
return new List<ExcelDataResource>()
{
new ExcelDataResource(){
SheetName="页签1",
TitleIndex=1,
SheetDataResource=objlist
},
new ExcelDataResource(){
SheetName="页签2",
TitleIndex=1,
SheetDataResource=Classobjlist
}
};
}

复制代码

生成DataToXSSFWorkbook工作簿

public static IWorkbook DataToXSSFWorkbook(List<ExcelDataResource> dataResources)
{
XSSFWorkbook _Workbook = new XSSFWorkbook();
if (dataResources == null && dataResources.Count == 0)
{
return _Workbook;
}
foreach (var sheetResource in dataResources)
{
if (sheetResource.SheetDataResource != null && sheetResource.SheetDataResource.Count == 0)
{
break;
}
ISheet sheet = _Workbook.CreateSheet(sheetResource.SheetName);
object obj = sheetResource.SheetDataResource[0];
Type type = obj.GetType();
List<PropertyInfo> propList = type.GetProperties().Where(c => c.IsDefined(typeof(TitleAttribute), true)).ToList();
IRow titleRow = sheet.CreateRow(0);
ICellStyle style = _Workbook.CreateCellStyle();
style.FillForegroundColor = NPOI.HSSF.Util.HSSFColor.Grey25Percent.Index;
style.FillPattern = FillPattern.SolidForeground;
style.FillBackgroundColor = NPOI.HSSF.Util.HSSFColor.Automatic.Index;
style.Alignment = HorizontalAlignment.CenterSelection;
style.VerticalAlignment = VerticalAlignment.Center;
titleRow.Height = 100 * 4;
for (int i = 0; i < propList.Count(); i++)
{
TitleAttribute propertyAttribute = propList[i].GetCustomAttribute<TitleAttribute>();
ICell cell = titleRow.CreateCell(i);
cell.SetCellValue(propertyAttribute.Title);
cell.CellStyle = style;
}
for (int i = 0; i < sheetResource.SheetDataResource.Count(); i++)
{
IRow row = sheet.CreateRow(i + 1);
object objInstance = sheetResource.SheetDataResource[i];
for (int j = 0; j < propList.Count; j++)
{
ICell cell = row.CreateCell(j);
cell.SetCellValue(propList[j].GetValue(objInstance).ToString());
}
}
}
return _Workbook;
}

复制代码

对应的使用的例子为:

List<ExcelDataResource> excelDataList = GetExcelDataList();
IWorkbook workbook1 = ExcelOperationHelper.DataToXSSFWorkbook(excelDataList);
using (FileStream file=new FileStream(path,FileMode.Create))
{
workbook1.Write(file);
file.Close();
}

复制代码

开发中的各种应用场景

写入Response二进制流

public void ImportExcelFileOnWriteResponse(int id)
{
///设置ContentType
HttpContext.Response.ContentType = "application/vnd.ms-excel";
///生成文件名
string fileName = DateTime.Now.ToString("yyyyMMddHHmmssffffff");
///设置Excel文件名
HttpContext.Response.Headers.Add("Content-Disposition", $"attachment;filename={fileName}.xls");
// 获取导出Excel需要的数据源
List<ExcelDataResource> excelDataResources = GetExcelSheetData(id);
byte[] bt = ExcelOperationHelper.ToExcelByteArray(excelDataResources);
HttpContext.Response.BodyWriter.WriteAsync(bt);
}

复制代码

调用框架的file方法

public IActionResult ImportExcelFileOnFileMethod(int id)
{
List<ExcelDataResource> excelDataResources = GetExcelSheetData(id);
byte[] bt = ExcelOperationHelper.ToExcelByteArray(excelDataResources);
string fileName = DateTime.Now.ToString("yyyyMMddHHmmssffffff");
return File(bt, "application/vnd.ms-excel", $"{fileName}.xls");
}

复制代码

扩展IActionResult方法 ExcelResult方法

public IActionResult ImportExcelFileOnActionResultExtend(int id)
{
// 获取导出Excel需要的数据源
List<ExcelDataResource> list = GetExcelSheetData(id);
return new ExcelResult(list); //调用IActionResult的扩展返回Excel
}

复制代码

对应IActionResult的实现

public class ExcelResult : IActionResult
{
private string _ExcelName;
private List<ExcelDataResource> _ExcelDataResources;
/// <summary>
/// 如果没有时间就默认以当前时间为文件名称
/// </summary>
/// <param name="excelDataResources"></param>
public ExcelResult(List<ExcelDataResource> excelDataResources) : this(DateTime.Now.ToString("yyyyMMddHHmmssffffff"), excelDataResources)
{
}
/// <summary>
/// 构造函数
/// </summary>
/// <param name="excelName">文件名称</param>
/// <param name="excelDataResources">数据源</param>
public ExcelResult(string excelName, List<ExcelDataResource> excelDataResources)
{
this._ExcelName = excelName;
this._ExcelDataResources = excelDataResources;
}
public Task ExecuteResultAsync(ActionContext context)
{
return Task.Run(() =>
{
context.HttpContext.Response.ContentType = "application/vnd.ms-excel";
context.HttpContext.Response.Headers.Add("Content-Disposition", $"attachment;filename={_ExcelName}.xls");
byte[] bt = ExcelOperationHelper.ToExcelByteArray(_ExcelDataResources);
context.HttpContext.Response.BodyWriter.WriteAsync(bt);
});
}
}

复制代码

excel导入

本质:目的是把Excel文件提交到服务器，然后把Excel文件中的数据信息读取出来，然后要处理的就是数据信息，
Excel文件的解析

Excel文件---文件流 fileStream MemoryStream Byte[]----->IWorkbook,如果得到了一个IWorkbook就可以使用Npoi来进行解析.

转换为DataTable

public static List<DataTable> ToExcelDateTable(IWorkbook hSSFWorkbook)
{
List<DataTable> datatableList = new List<DataTable>();
for (int sheetIndex = 0; sheetIndex < hSSFWorkbook.NumberOfSheets; sheetIndex++)
{
ISheet sheet = hSSFWorkbook.GetSheetAt(sheetIndex);
//获取表头 FirstRowNum 第一行索引 0
IRow header = sheet.GetRow(sheet.FirstRowNum);//获取第一行
if (header == null)
{
break;
}
int startRow = 0;//数据的第一行索引
DataTable dtNpoi = new DataTable();
startRow = sheet.FirstRowNum + 1;
for (int i = header.FirstCellNum; i < header.LastCellNum; i++)
{
ICell cell = header.GetCell(i);
if (cell != null)
{
string cellValue = $"Column{i + 1}_{cell.ToString()}";
if (cellValue != null)
{
DataColumn col = new DataColumn(cellValue);
dtNpoi.Columns.Add(col);
}
else
{
DataColumn col = new DataColumn();
dtNpoi.Columns.Add(col);
}
}
}
//数据 LastRowNum 最后一行的索引如第九行---索引 8
for (int i = startRow; i <= sheet.LastRowNum; i++)
{
IRow row = sheet.GetRow(i);//获取第i行
if (row == null)
{
continue;
}
DataRow dr = dtNpoi.NewRow();
//遍历每行的单元格
for (int j = row.FirstCellNum; j < row.LastCellNum; j++)
{
if (row.GetCell(j) != null)
dr[j] = row.GetCell(j).ToString();
}
dtNpoi.Rows.Add(dr);
}
datatableList.Add(dtNpoi);
}
return datatableList;
}

复制代码

序列化和反序列化

序列化(Serialization)是将对象的状态信息转换为可以存储或传输的形式的过程。在序列化期间，对象将其当前状态写入到临时或永久性存储区。以后，可以通过存储区中读取或反序列化对象的状态，重新创建该对象。
序列化之前:对象
序列化之后:把一个对象转换成另外一种形式来存储。
原始数据:

public IActionResult ImportExcelOnFormSubmit()
{
//获取上传的Excel文件
IFormFile file = Request.Form.Files["file"];
if (file != null && file.Length > 0)
{
string suffixName = Path.GetExtension(file.FileName).ToLower();
if (suffixName != ".xls" && suffixName != ".xlsx")
{
return Content("请导入文件为Excel格式");
}
XSSFWorkbook hSSFWorkbook = new XSSFWorkbook(file.OpenReadStream());
List<DataTable> datatableList = ExcelOperationHelper.ToExcelDateTable(hSSFWorkbook);
ViewBag.Info = Newtonsoft.Json.JsonConvert.SerializeObject(datatableList);
}
else
{
ViewBag.Info = "请上传文件";
}
return View();
}

复制代码

XML序列化

public class DataFactory
{
/// <summary>
/// 初始化数据的
/// </summary>
/// <returns></returns>
public static List<Programmer> BuildProgrammerList()
{
#region data prepare
List<Programmer> list = new List<Programmer>();
list.Add(new Programmer()
{
Id = 1,
Description = "Richard老师的学员",
Name = "SoWhat",
Sex = "男"
});
list.Add(new Programmer()
{
Id = 1,
Description = "Richard老师的学员",
Name = "day",
Sex = "男"
});
list.Add(new Programmer()
{
Id = 1,
Description = "Richard老师的学员",
Name = "领悟",
Sex = "男"
});
list.Add(new Programmer()
{
Id = 1,
Description = "Richard老师的学员",
Name = "Sam",
Sex = "男"
});
list.Add(new Programmer()
{
Id = 1,
Description = "Richard老师的学员",
Name = "AlphaGo",
Sex = "男"
});
list.Add(new Programmer()
{
Id = 1,
Description = "Richard老师的学员",
Name = "折腾",
Sex = "男"
});
list.Add(new Programmer()
{
Id = 1,
Description = "Richard老师的学员",
Name = "Me860",
Sex = "男"
});
list.Add(new Programmer()
{
Id = 1,
Description = "Richard老师的学员",
Name = "打兔子的猎人",
Sex = "男"
});
list.Add(new Programmer()
{
Id = 1,
Description = "Richard老师的学员",
Name = "Nine",
Sex = "女"
});
list.Add(new Programmer()
{
Id = 1,
Description = "Richard老师的学员",
Name = "望",
Sex = "女"
});
list.Add(new Programmer()
{
Id = 1,
Description = "Richard老师的学员",
Name = "微笑刺客",
Sex = "男"
});
list.Add(new Programmer()
{
Id = 1,
Description = "Richard老师的学员",
Name = "waltz",
Sex = "男"
});
list.Add(new Programmer()
{
Id = 1,
Description = "Richard老师的学员",
Name = "爱在昨天",
Sex = "男"
});
list.Add(new Programmer()
{
Id = 1,
Description = "Richard老师的学员",
Name = "waltz",
Sex = "男"
});
#endregion
return list;
}
}
[Serializable] //必须添加序列化特性
public class Person
{
[NonSerialized]
public int Id = 1;
public string Name { get; set; }
public string Sex { get; set; }
}
[Serializable] //必须添加序列化特性
public class Programmer : Person
{
private string Language { get; set; }//编程语言
public string Description { get; set; }
}

复制代码

jSON序列化

public class XmlHelper
{
/// <summary>
/// XmlSerializer序列化实体为字符串
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="t"></param>
/// <returns></returns>
public static string ToXml<T>(T t) where T : new()
{
XmlSerializer xmlSerializer = new XmlSerializer(t.GetType());
Stream stream = new MemoryStream();
xmlSerializer.Serialize(stream, t);
stream.Position = 0;
StreamReader reader = new StreamReader(stream);
string text = reader.ReadToEnd();
return text;
}
/// <summary>
/// 字符串序列化成XML
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="content"></param>
/// <returns></returns>
public static T ToObject<T>(string content) where T : new()
{
using (MemoryStream stream = new MemoryStream(Encoding.UTF8.GetBytes(content)))
{
XmlSerializer xmlFormat = new XmlSerializer(typeof(T));
return (T)xmlFormat.Deserialize(stream);
}
}
/// <summary>
/// 文件反序列化成实体
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="fileName"></param>
/// <returns></returns>
public static T FileToObject<T>(string fileName) where T : new()
{
fileName = Path.Combine(Constant.basePath, "File", @"Student.xml");
using (Stream fStream = new FileStream(fileName, FileMode.Open, FileAccess.ReadWrite))
{
XmlSerializer xmlFormat = new XmlSerializer(typeof(T));
return (T)xmlFormat.Deserialize(fStream);
}
}
}

复制代码

调用的实例

public class JsonHelper
{
#region Json
/// <summary>
/// JavaScriptSerializer
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="obj"></param>
/// <returns></returns>
public static string ObjectToString<T>(T obj)
{
JavaScriptSerializer jss = new JavaScriptSerializer();
return jss.Serialize(obj);
}
/// <summary>
/// JavaScriptSerializer
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="content"></param>
/// <returns></returns>
public static T StringToObject<T>(string content)
{
JavaScriptSerializer jss = new JavaScriptSerializer();
return jss.Deserialize<T>(content);
}
/// <summary>
/// JsonConvert.SerializeObject
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="obj"></param>
/// <returns></returns>
public static string ToJson<T>(T obj)
{
return JsonConvert.SerializeObject(obj);
}
/// <summary>
/// JsonConvert.DeserializeObject
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="content"></param>
/// <returns></returns>
public static T ToObject<T>(string content)
{
try
{
return JsonConvert.DeserializeObject<T>(content);
}
catch (Exception)
{
throw;
}
}
#endregion Json
}

复制代码

来源:https://www.cnblogs.com/wenlong-4613615/p/18222548
免责声明：由于采集信息均来自互联网，如果侵犯了您的权益，请联系我们【E-Mail:cb@itdo.tech】我们会及时删除侵权内容，谢谢合作！