【C#】C#使用OleDb将数据导出到Excel文件

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方法：

public class ExcelHelper
{
    /// <summary>
    /// 将数据导出至Excel文件
    /// </summary>
    /// <param name="Table">DataTable对象</param>
    /// <param name="ExcelFilePath">Excel文件路径</param>
    public static bool OutputToExcel(DataTable Table, string ExcelFilePath)
    {
        if (File.Exists(ExcelFilePath))
        {
            throw new Exception("该文件已经存在！");
        }

        if ((Table.TableName.Trim().Length == 0) || (Table.TableName.ToLower() == "table"))
        {
            Table.TableName = "Sheet1";
        }

        //数据表的列数
        int ColCount = Table.Columns.Count;

        //用于记数，实例化参数时的序号
        int i = 0;

        //创建参数
        OleDbParameter[] para = new OleDbParameter[ColCount];

        //创建表结构的SQL语句
        string TableStructStr = @"Create Table " + Table.TableName + "(";

        //连接字符串
        string connString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + ExcelFilePath + ";Extended Properties=Excel 8.0;";
        OleDbConnection objConn = new OleDbConnection(connString);

        //创建表结构
        OleDbCommand objCmd = new OleDbCommand();

        //数据类型集合
        ArrayList DataTypeList = new ArrayList();
        DataTypeList.Add("System.Decimal");
        DataTypeList.Add("System.Double");
        DataTypeList.Add("System.Int16");
        DataTypeList.Add("System.Int32");
        DataTypeList.Add("System.Int64");
        DataTypeList.Add("System.Single");

        //遍历数据表的所有列，用于创建表结构
        foreach (DataColumn col in Table.Columns)
        {
            //如果列属于数字列，则设置该列的数据类型为double
            if (DataTypeList.IndexOf(col.DataType.ToString()) >= 0)
            {
                para[i] = new OleDbParameter("@" + col.ColumnName, OleDbType.Double);
                objCmd.Parameters.Add(para[i]);

                //如果是最后一列
                if (i + 1 == ColCount)
                {
                    TableStructStr += col.ColumnName + " double)";
                }
                else
                {
                    TableStructStr += col.ColumnName + " double,";
                }
            }
            else
            {
                para[i] = new OleDbParameter("@" + col.ColumnName, OleDbType.VarChar);
                objCmd.Parameters.Add(para[i]);

                //如果是最后一列
                if (i + 1 == ColCount)
                {
                    TableStructStr += col.ColumnName + " varchar)";
                }
                else
                {
                    TableStructStr += col.ColumnName + " varchar,";
                }
            }
            i++;
        }

        //创建Excel文件及文件结构
        try
        {
            objCmd.Connection = objConn;
            objCmd.CommandText = TableStructStr;

            if (objConn.State == ConnectionState.Closed)
            {
                objConn.Open();
            }
            objCmd.ExecuteNonQuery();
        }
        catch (Exception exp)
        {
            throw exp;
        }

        //插入记录的SQL语句
        string InsertSql_1 = "Insert into " + Table.TableName + " (";
        string InsertSql_2 = " Values (";
        string InsertSql = "";

        //遍历所有列，用于插入记录，在此创建插入记录的SQL语句
        for (int colID = 0; colID < ColCount; colID++)
        {
            if (colID + 1 == ColCount)  //最后一列
            {
                InsertSql_1 += Table.Columns[colID].ColumnName + ")";
                InsertSql_2 += "@" + Table.Columns[colID].ColumnName + ")";
            }
            else
            {
                InsertSql_1 += Table.Columns[colID].ColumnName + ",";
                InsertSql_2 += "@" + Table.Columns[colID].ColumnName + ",";
            }
        }

        InsertSql = InsertSql_1 + InsertSql_2;

        //遍历数据表的所有数据行
        for (int rowID = 0; rowID < Table.Rows.Count; rowID++)
        {
            for (int colID = 0; colID < ColCount; colID++)
            {
                if (para[colID].DbType == DbType.Double && Table.Rows[rowID][colID].ToString().Trim() == "")
                {
                    para[colID].Value = 0;
                }
                else
                {
                    para[colID].Value = Table.Rows[rowID][colID].ToString().Trim();
                }
            }
            try
            {
                objCmd.CommandText = InsertSql;
                objCmd.ExecuteNonQuery();
            }
            catch (Exception exp)
            {
                string str = exp.Message;
            }
        }
        try
        {
            if (objConn.State == ConnectionState.Open)
            {
                objConn.Close();
            }
        }
        catch (Exception exp)
        {
            throw exp;
        }
        return true;
    }
}

使用：

System.Data.DataTable dt = new System.Data.DataTable();
dt.TableName = "用户记录";

dt.Columns.Add("ID", typeof(string));
dt.Columns.Add("姓名", typeof(string));
dt.Columns.Add("年龄", typeof(string));

List<UserInfo> list = new List<UserInfo>();
list.Add(new UserInfo() { Id = 10001, Name = "Bob", Age = 20 });
list.Add(new UserInfo() { Id = 10002, Name = "Alice", Age = 18 });
list.Add(new UserInfo() { Id = 10003, Name = "David", Age = 19 });

for (int i = 0; i < list.Count; i++)
{
    DataRow dr = dt.NewRow();
    dr["ID"] = list[i].Id;
    dr["姓名"] = list[i].Name;
    dr["年龄"] = list[i].Age;

    dt.Rows.Add(dr);
}

//保存到Excel文件中.xls
ExcelHelper.OutputToExcel(dt, @"E:\BT\Users.xls");

效果：

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