C#创建、读取和修改Excel的方法

// Namespaces,Variables,and Constants
using System;
using System.Configuration;
using System.Data;
private OleDbDataAdapter da;
private DataTable dt;
private void Excel_Load(object sender,System.EventArgs e)
{
    // Create the DataAdapter.
    da = new OleDbDataAdapter("SELECT * FROM [Sheet1$]",ConfigurationSettings.AppSettings["ExcelConnectString1"]);
    // Create the insert command.
    String insertSql = "INSERT INTO [Sheet1$] (CategoryID,CategoryName,Description) VALUES (?,?,?)";
    da.InsertCommand = new OleDbCommand(insertSql,da.SelectCommand.Connection);
    da.InsertCommand.Parameters.Add("@CategoryID",OleDbType.Integer,"CategoryID");
    da.InsertCommand.Parameters.Add("@CategoryName",OleDbType.Char,15,"CategoryName");
    da.InsertCommand.Parameters.Add("@Description",OleDbType.VarChar,100,"Description");
    // Create the update command.
    String updateSql = "UPDATE [Sheet1$] SET CategoryName=?,Description=? " WHERE CategoryID=?";
    da.UpdateCommand = new OleDbCommand(updateSql,da.SelectCommand.Connection);
    da.UpdateCommand.Parameters.Add("@CategoryName","CategoryName");
    da.UpdateCommand.Parameters.Add("@Description","Description");
    da.UpdateCommand.Parameters.Add("@CategoryID","CategoryID");
    // Fill the table from the Excel spreadsheet.
    dt = new DataTable( );
    da.Fill(dt);
    // Define the primary key.
    dt.PrimaryKey = new DataColumn[] {dt.Columns[0]};
    // Records can only be inserted using this technique.
    dt.DefaultView.AllowDelete = false;
    dt.DefaultView.AllowEdit = true;
    dt.DefaultView.AllowNew = true;
    // Bind the default view of the table to the grid.
    dataGrid.DataSource = dt.DefaultView;
}
private void updateButton_Click(object sender,System.EventArgs e)
{
    da.Update(dt);
}