ASP.NET操作Excel助手代码指南，如何编写相关代码？

在ASP.NET中操作Excel文件时，通常会使用到ADO.NET的OleDb连接来进行数据的读写，以下是一个简单的ExcelHelper类的实现，它封装了对Excel文件的基本操作：

ExcelHelper类代码

using System;
using System.Data;
using System.Data.OleDb;
using System.IO;
public partial class ExcelHelper : IDisposable
{
    #region Fields
    private string _excelObject = "Provider=Microsoft.{0}.OLEDB.{1};Data Source={2};Extended Properties="Excel {3};HDR={4};IMEX={5}"";
    private string _filepath = string.Empty;
    private string _hdr = "No";
    private string _imex = "1";
    private OleDbConnection _con = null;
    #endregion
    #region Constructor
    public ExcelHelper(string filePath)
    {
        this._filepath = filePath;
    }
    #endregion
    #region Properties
    /// <summary>
    /// 获取连接字符串
    /// </summary>
    public string ConnectionString
    {
        get
        {
            string result = string.Empty;
            if (String.IsNullOrEmpty(this._filepath))
                return result;
            //检查文件格式
            FileInfo fi = new FileInfo(this._filepath);
            if (fi.Extension.Equals(".xls"))
            {
                result = string.Format(this._excelObject, "Jet", "4.0", this._filepath, "8.0", this._hdr, this._imex);
            }
            else if (fi.Extension.Equals(".xlsx"))
            {
                result = string.Format(this._excelObject, "Ace", "12.0", this._filepath, "12.0", this._hdr, this._imex);
            }
            return result;
        }
    }
    /// <summary>
    /// 获取连接
    /// </summary>
    public OleDbConnection Connection
    {
        get
        {
            if (_con == null)
            {
                this._con = new OleDbConnection();
                this._con.ConnectionString = this.ConnectionString;
            }
            return this._con;
        }
    }
    /// <summary>
    /// HDR
    /// </summary>
    public string Hdr
    {
        get { return this._hdr; }
        set { this._hdr = value; }
    }
    /// <summary>
    /// IMEX
    /// </summary>
    public string Imex
    {
        get { return this._imex; }
        set { this._imex = value; }
    }
    #endregion
    #region Methods
    /// <summary>
    /// Gets a schema
    /// </summary>
    /// <returns>Schema</returns>
    public DataTable GetSchema()
    {
        DataTable dtSchema = null;
        if (this.Connection.State != ConnectionState.Open) this.Connection.Open();
        dtSchema = this.Connection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });
        return dtSchema;
    }
    private string GetTableName()
    {
        string tableName = string.Empty;
        DataTable dt = GetSchema();
        for (int i = 0; i < dt.Rows.Count; i++)
        {
            tableName += dt.Rows[i][2].ToString().Trim();
        }
        return tableName.Substring(0, tableName.Length 1);
    }
    public DataTable ReadTable()
    {
        return this.ReadTable(GetTableName(), ExcelHelperReadTableMode.ReadFromWorkSheet);
    }
    /// <summary>
    /// Read all table rows
    /// </summary>
    /// <param name="tableName">Table Name</param>
    /// <returns>Table</returns>
    public DataTable ReadTable(string tableName)
    {
        return this.ReadTable(tableName, ExcelHelperReadTableMode.ReadFromWorkSheet);
    }
    /// <summary>
    /// Read table
    /// </summary>
    /// <param name="tableName">Table Name</param>
    /// <param name="mode">Read mode</param>
    /// <returns>Table</returns>
    public DataTable ReadTable(string tableName, ExcelHelperReadTableMode mode)
    {
        return this.ReadTable(tableName, mode, "");
    }
    /// <summary>
    /// Read table with additional criteria
    /// </summary>
    /// <param name="tableName">Table Name</param>
    /// <param name="mode">Read mode</param>
    /// <param name="criteria">Additional criteria for reading</param>
    /// <returns>Table</returns>
    public DataTable ReadTable(string tableName, ExcelHelperReadTableMode mode, string criteria)
    {
        DataTable dt = new DataTable();
        using (OleDbCommand command = new OleDbCommand())
        {
            command.Connection = this.Connection;
            if (mode == ExcelHelperReadTableMode.ReadFromWorkSheet)
            {
                command.CommandText = "SELECT  FROM [" + tableName + "]";
            }
            else if (mode == ExcelHelperReadTableMode.ReadFromQuery)
            {
                command.CommandText = "SELECT  FROM [" + tableName + "] WHERE " + criteria;
            }
            using (OleDbDataAdapter adapter = new OleDbDataAdapter(command))
            {
                adapter.Fill(dt);
            }
        }
        return dt;
    }
    #endregion
    #region IDisposable Support
    private bool disposedValue = false; // To detect redundant calls
    protected virtual void Dispose(bool disposing)
    {
        if (!disposedValue)
        {
            if (disposing)
            {
                // TODO: dispose managed state (managed objects).
                if (_con != null && _con.State == ConnectionState.Open)
                {
                    _con.Close();
                }
                _con = null;
            }
            // TODO: free unmanaged resources (unmanaged objects) and override a finalizer below.
            // TODO: set large fields to null.
            disposedValue = true;
        }
    }
    // TODO: override a finalizer only if Dispose(bool disposing) above has code to free unmanaged resources.
    // ~ExcelHelper() {
    //    Dispose(false);
    // }
    // This code added to correctly implement the disposable pattern.
    public void Dispose()
    {
        // Do not change this code. Put cleanup code in Dispose(bool disposing) above.
        Dispose(true);
        // TODO: uncomment the following line if the finalizer is overridden above.
        // GC.SuppressFinalize(this);
    }
    #endregion
}

使用示例

以下是如何使用ExcelHelper类的一个简单示例：

string filePath = Server.MapPath("~/App_Data/example.xlsx");
ExcelHelper excelHelper = new ExcelHelper(filePath);
excelHelper.Hdr = "Yes"; //设置第一行包含列名
DataTable dt = excelHelper.ReadTable(); //读取Excel文件中的第一个工作表数据到DataTable中
GridView1.DataSource = dt; //绑定到GridView显示数据
GridView1.DataBind(); //刷新GridView显示数据