【办公软件】C#调用NPOI实现Excel文件的加载、导出功能

文章目录

- 1. 引言
- 2. 环境准备
- 3. 示例代码
- 4. 结果
- 5. 总结

1. 引言

本文将介绍如何使用C#和NPOI库实现Excel文件的读写操作，并通过加载文件和导出文件的按钮进行封装。NPOI是一个强大的.NET库，可以轻松处理Excel文件。我们将学习如何使用NPOI打开现有的Excel文件、读取数据，并将数据写入到Excel文件中。

2. 环境准备

在开始之前，请确保已安装以下环境：

Visual Studio（任何版本）
NPOI库

3. 示例代码

下面是一个示例代码，演示了如何使用C#和NPOI实现Excel文件的读写操作，并封装在函数中，同时添加加载文件和导出文件的按钮：

using System;
using System.Data;
using System.IO;
using System.Windows.Forms;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;class Program
{static void Main(string[] args){Application.Run(new Form1());}
}public class Form1 : Form
{private Button loadButton;private Button exportButton;private DataTable dataTable;public Form1(){loadButton = new Button();loadButton.Text = "加载文件";loadButton.Click += LoadButton_Click;exportButton = new Button();exportButton.Text = "导出文件";exportButton.Click += ExportButton_Click;Controls.Add(loadButton);Controls.Add(exportButton);}private void LoadButton_Click(object sender, EventArgs e){OpenFileDialog openFileDialog = new OpenFileDialog();openFileDialog.Filter = "Excel文件 (*.xlsx)|*.xlsx";openFileDialog.Title = "选择要加载的Excel文件";if (openFileDialog.ShowDialog() == DialogResult.OK){string filePath = openFileDialog.FileName;dataTable = LoadExcelFile(filePath);}}private void ExportButton_Click(object sender, EventArgs e){if (dataTable == null){MessageBox.Show("请先加载Excel文件！", "错误", MessageBoxButtons.OK, MessageBoxIcon.Error);return;}SaveFileDialog saveFileDialog = new SaveFileDialog();saveFileDialog.Filter = "Excel文件 (*.xlsx)|*.xlsx";saveFileDialog.Title = "选择要导出的Excel文件路径";if (saveFileDialog.ShowDialog() == DialogResult.OK){string filePath = saveFileDialog.FileName;ExportExcelFile(filePath, dataTable);}}private DataTable LoadExcelFile(string filePath){DataTable dataTable = new DataTable();FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read);XSSFWorkbook workbook = new XSSFWorkbook(file);ISheet sheet = workbook.GetSheetAt(0);// 读取表头IRow headerRow = sheet.GetRow(0);for (int i = 0; i < headerRow.LastCellNum; i++){dataTable.Columns.Add(headerRow.GetCell(i).ToString());}// 读取数据for (int row = 1; row <= sheet.LastRowNum; row++){IRow currentRow = sheet.GetRow(row);DataRow dataRow = dataTable.NewRow();for (int col = 0; col < currentRow.LastCellNum; col++){dataRow[col] = currentRow.GetCell(col)?.ToString();}dataTable.Rows.Add(dataRow);}file.Close();Console.WriteLine("加载文件完成！");return dataTable;}private void ExportExcelFile(string filePath, DataTable dataTable){XSSFWorkbook workbook = new XSSFWorkbook();ISheet sheet = workbook.CreateSheet("Sheet1");// 写入表头IRow headerRow = sheet.CreateRow(0);for (int i = 0; i < dataTable.Columns.Count; i++){headerRow.CreateCell(i).SetCellValue(dataTable.Columns[i].ColumnName);}// 写入数据for (int row = 0; row < dataTable.Rows.Count; row++){IRow newRow = sheet.CreateRow(row + 1);for (int col = 0; col < dataTable.Columns.Count; col++){newRow.CreateCell(col).SetCellValue(dataTable.Rows[row][col]?.ToString());}}FileStream writeFile = new FileStream(filePath, FileMode.Create, FileAccess.Write);workbook.Write(writeFile);writeFile.Close();Console.WriteLine("导出文件完成！");}
}