我想编写代码将 DataColumn 添加到 DataTable，但是当我保存 DataTable 时，它不包含新的 DataColumn。
它保存我添加的任何新 DataRows，但不保存 DataColumns。
有人可以告诉我我做错了什么吗？
public partial class Form1 : Form
{
MyDatabase DB;
DataTable Products;
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
DB = new MyDatabase();
DB.Open(@"C:\Users\Grant\Documents\Database.accdb");
Products = DB.GetTable("Products");
AddColumn();
AddRow();
DB.Save(Products);
}
private void AddColumn()
{
DataColumn Column = new DataColumn();
Column.DataType = Type.GetType("System.String");
Column.ColumnName = "TestColumn";
Products.Columns.Add(Column);
}
private void AddRow()
{
DataRow Row;
Row = Products.Rows.Add(1, "B", "C");
}
}
class MyDatabase
{
// The following program has to be installed on the computer
// http://www.microsoft.com/downloads/en/details.aspx?familyid=7554F536-8C28-4598-9B72-EF94E038C891&displaylang=en
private String provider = "Microsoft.ACE.OLEDB.12.0";
private String source;
private OleDbConnection connection;
private String connectionString;
private DataSet dataSet = new DataSet();
private OleDbDataAdapter adapter;
private OleDbCommandBuilder commandBuilder;
public String Provider
{
get { return provider; }
set { provider = value; }
}
public String Source
{
get { return Source; }
set { source = value; }
}
public void Open(String Filename)
{
connectionString = @"Provider=" + provider + @";Data Source=" + Filename;
connection = new OleDbConnection(connectionString);
connection.Open();
adapter = new OleDbDataAdapter();
}
public void BuildStrings()
{
commandBuilder = new OleDbCommandBuilder(adapter);
adapter.UpdateCommand = commandBuilder.GetUpdateCommand();
adapter.InsertCommand = commandBuilder.GetInsertCommand();
adapter.DeleteCommand = commandBuilder.GetDeleteCommand();
}
public DataTable GetTable(String TableName)
{
adapter.SelectCommand = new OleDbCommand("SELECT * From " + TableName, connection);
BuildStrings();
adapter.Fill(dataSet, TableName);
return dataSet.Tables[TableName];
}
public void Save(DataTable Table)
{
adapter.Update(Table);
adapter.Update(dataSet, "Products");
}
}