using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Text;
using System.Windows.Forms;namespace label
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
} public DataTable CX(string sql)
{
string connection = "Server=(local);uid=;pwd=";
SqlDataAdapter DA = new SqlDataAdapter(sql, connection);
DataTable DT = new DataTable();
DA.Fill(DT);
return DT;
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
string connection = "Server=(local);uid=;pwd=";
SqlConnection conn = new SqlConnection(connection);
conn.Open();
string comtext="SELECT * FROM [TABLE]";
SqlCommand com = new SqlCommand(comtext, conn);
SqlDataReader dr =com.ExecuteReader();
if (dr.Read())
{
DataTable table=new DataTable ();
this.Text = (string)table.Rows[2][3];
}
}
}
}
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Text;
using System.Windows.Forms;namespace label
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
} public DataTable CX(string sql)
{
string connection = "Server=(local);uid=;pwd=";
SqlDataAdapter DA = new SqlDataAdapter(sql, connection);
DataTable DT = new DataTable();
DA.Fill(DT);
return DT;
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
string connection = "Server=(local);uid=;pwd=";
SqlConnection conn = new SqlConnection(connection);
conn.Open();
string comtext="SELECT * FROM [TABLE]";
SqlCommand com = new SqlCommand(comtext, conn);
SqlDataReader dr =com.ExecuteReader();
if (dr.Read())
{
DataTable table=new DataTable ();
this.Text = (string)table.Rows[2][3];
}
}
}
}
{
string connection = "Server=(local);uid=;pwd=";
SqlConnection conn = new SqlConnection(connection);
conn.Open();
string comtext="SELECT * FROM [TABLE]";
SqlCommand com = new SqlCommand(comtext, conn);
SqlDataReader dr =com.ExecuteReader();
if (dr.Read())
{
DataTable table=new DataTable ();
this.Text = (string)table.Rows[2][3]; 这里明显读取不到数据阿
要么你用dr["column"]; 要么你用上面的SqlDataAdapter填充到dataset里面
}
}
}
你new了一个新的DataTable然后,没有对其填充值,然后你就用第二行第三列的字段,所以程序报错
{
string connection = "Server=(local);uid=;pwd=";
SqlConnection conn = new SqlConnection(connection);
conn.Open();
string comtext="SELECT * FROM [TABLE]";
SqlCommand com = new SqlCommand(comtext, conn);
SqlDataReader dr =com.ExecuteReader();
if (dr.Read())
{
this.Text = dr.GetString(dr.GetOrdinal("你要绑定的列名"));
}
}
this.Text = (string)table.Rows[2][3];
改
this.Text =dr[列];
this.Text = (string)table.Rows[2][3];
table是刚new 的,里面什么都没有.