C# Excel操作

 记住这个参数：IMEX=0

0：写入

1：读取

2：写入和读取

用2好像没用 没深究

读取Excel 返回 DataSet：

ToDataTable("E:\2.xlsx")；

public static DataSet ToDataTable(string filePath)
        {
            string connStr = "";
            string fileType = System.IO.Path.GetExtension(filePath);
            if (string.IsNullOrEmpty(fileType)) return null;

            if (fileType == ".xls")
                connStr = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + filePath + ";" + ";Extended Properties="Excel 8.0;HDR=YES;IMEX=1"";
            else
                connStr = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + filePath + ";" + ";Extended Properties="Excel 12.0;HDR=YES;IMEX=1"";
            string sql_F = "Select * FROM [{0}]";

            OleDbConnection conn = null;
            OleDbDataAdapter da = null;
            DataTable dtSheetName = null;

            DataSet ds = new DataSet();
            try
            {
                // 初始化连接，并打开  
                conn = new OleDbConnection(connStr);
                conn.Open();

                // 获取数据源的表定义元数据                         
                string SheetName = "";
                dtSheetName = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });

                // 初始化适配器  
                da = new OleDbDataAdapter();
                for (int i = 0; i < dtSheetName.Rows.Count; i++)
                {
                    SheetName = (string)dtSheetName.Rows[i]["TABLE_NAME"];

                    if (SheetName.Contains("$") && !SheetName.Replace("'", "").EndsWith("$"))
                    {
                        continue;
                    }

                    da.SelectCommand = new OleDbCommand(String.Format(sql_F, SheetName), conn);
                    DataSet dsItem = new DataSet();
                    da.Fill(dsItem, "table" + i);

                    ds.Tables.Add(dsItem.Tables[0].Copy());
                }
            }
            catch (Exception ex)
            {
            }
            finally
            {
                // 关闭连接  
                if (conn.State == ConnectionState.Open)
                {
                    conn.Close();
                    da.Dispose();
                    conn.Dispose();
                }
            }
            return ds;
        }

传入DataSet保存到Excel

DataSetToExcel("E:\2.xlsx", DataSet, "表名");

        public static void DataSetToExcel(string filePath, DataSet ds, string tableName)
        {
            DataTable dt = ds.Tables[0];
            string connStr = "";
            string fileType = System.IO.Path.GetExtension(filePath);
            if (string.IsNullOrEmpty(fileType)) return;

            if (fileType == ".xls")
                connStr = string.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties='Excel 8.0;HDR=Yes;IMEX=0;'", filePath);
            else
                connStr = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + filePath + ";" + ";Extended Properties="Excel 12.0;HDR=YES;IMEX=0"";
 
            try
            {
                using (OleDbConnection conn = new OleDbConnection(connStr))
                {
                    conn.Open();
                    //创建表格字段
                    StringBuilder strSQL = new StringBuilder();
                    strSQL.Append("CREATE TABLE ").Append("[" + tableName + "]");
                    strSQL.Append("(");
                    for (int i = 0; i < dt.Columns.Count; i++)
                    {
                        strSQL.Append("[" + dt.Columns[i].ColumnName + "] text,");
                    }
                    strSQL = strSQL.Remove(strSQL.Length - 1, 1);
                    strSQL.Append(")");

                    OleDbCommand cmd = new OleDbCommand(strSQL.ToString(), conn);
                    cmd.ExecuteNonQuery();


　　　　　　　　　　　　//添加数据
                    for (int i = 0; i < dt.Rows.Count; i++)
                    {
                        strSQL.Clear();
                        StringBuilder strvalue = new StringBuilder();
                        for (int j = 0; j < dt.Columns.Count; j++)
                        {
                            strvalue.Append("'" + dt.Rows[i][j].ToString() + "'");
                            if (j != dt.Columns.Count - 1)
                            {
                                strvalue.Append(",");
                            }
                        }
                        cmd.CommandText = strSQL.Append(" insert into [" + tableName + "] values (").Append(strvalue).Append(")").ToString();
                        cmd.ExecuteNonQuery();
                    }
                    conn.Close();
                }
            }
            catch (Exception ex)
            {
            }
            
        }