连接数据库:
using System;
using System.Collections.Generic;
using System.Text;
using System.Data.OleDb;namespace tyjxc.Method
{
public class getSqlConnection
{ #region 代码中用到的变量
string G_Str_ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=tyjxc.mdb ;Persist Security Info=False;Jet OLEDB:Database Password=";
OleDbConnection G_Con; //声明链接对象
#endregion #region 构造函数
/// <summary>
/// 构造函数
/// </summary>
public getSqlConnection()
{ }
#endregion #region 连接数据库
/// <summary>
/// 连接数据库
/// </summary>
/// <returns></returns>
public OleDbConnection GetCon()
{
G_Con = new OleDbConnection(G_Str_ConnectionString);
G_Con.Open();
return G_Con;
}
#endregion
}
}datagridview绑定数据:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;
using tyjxc.Method;private void class_list()
{ getSqlConnection getConnection = new getSqlConnection();
conn = getConnection.GetCon(); string sql = "select kh_classid as 编号,kh_classname as 客户分类 from kh_class order by kh_classid"; dataAdapter = new OleDbDataAdapter(sql, conn);
OleDbCommandBuilder commandBuilder = new OleDbCommandBuilder(dataAdapter);
DataTable table = new DataTable();
table.Locale = System.Globalization.CultureInfo.InvariantCulture;
dataAdapter.Fill(table);
bindingSource1.DataSource = table;
dataGridView1.DataSource = bindingSource1;
conn.Dispose();
}修改后保存datagridview的代码:
dataAdapter.Update((DataTable)bindingSource1.DataSource);
提示connectionstring 属性尚未初始化?请教高人,这是什么问题,我应该如何修改?谢谢。
using System;
using System.Collections.Generic;
using System.Text;
using System.Data.OleDb;namespace tyjxc.Method
{
public class getSqlConnection
{ #region 代码中用到的变量
string G_Str_ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=tyjxc.mdb ;Persist Security Info=False;Jet OLEDB:Database Password=";
OleDbConnection G_Con; //声明链接对象
#endregion #region 构造函数
/// <summary>
/// 构造函数
/// </summary>
public getSqlConnection()
{ }
#endregion #region 连接数据库
/// <summary>
/// 连接数据库
/// </summary>
/// <returns></returns>
public OleDbConnection GetCon()
{
G_Con = new OleDbConnection(G_Str_ConnectionString);
G_Con.Open();
return G_Con;
}
#endregion
}
}datagridview绑定数据:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;
using tyjxc.Method;private void class_list()
{ getSqlConnection getConnection = new getSqlConnection();
conn = getConnection.GetCon(); string sql = "select kh_classid as 编号,kh_classname as 客户分类 from kh_class order by kh_classid"; dataAdapter = new OleDbDataAdapter(sql, conn);
OleDbCommandBuilder commandBuilder = new OleDbCommandBuilder(dataAdapter);
DataTable table = new DataTable();
table.Locale = System.Globalization.CultureInfo.InvariantCulture;
dataAdapter.Fill(table);
bindingSource1.DataSource = table;
dataGridView1.DataSource = bindingSource1;
conn.Dispose();
}修改后保存datagridview的代码:
dataAdapter.Update((DataTable)bindingSource1.DataSource);
提示connectionstring 属性尚未初始化?请教高人,这是什么问题,我应该如何修改?谢谢。
{ getSqlConnection getConnection = new getSqlConnection();
从getSqlConnection getConnection = new getSqlConnection();
设置断点.慢慢看.F11一步一步的找.看是哪里报的错误.
---------------------
既然连接后面还要使用,这儿就不要Dispose。
否则,后面就重新初始化。
connectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\studentSystem.mdb"
你的table是本地内存中的.是脱机数据
bindingSource1.DataSource = table; bindingSource1.DataSource是一个脱机数据,根本没和数据库进行双向绑定,修改后保存datagridview的代码:
dataAdapter.Update((DataTable)bindingSource1.DataSource);
所以你想把更改后的内存数据提交到数据库去是不可能的.即根本没跟数据库建立连接,
所以 提示connectionstring 属性尚未初始化? 是正常的
应该是这里的原因,你这里已经释放了,而后面又用到了
把这个去掉试试
private OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=jinxiaocun.mdb ;Persist Security Info=False;Jet OLEDB:Database Password=;");这样是可以保存的只是最近专门把链接数据库写成一个类文件,才出的这个问题。