**
以下是获取数据库数据的两种写法:
**
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace DataReader
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
ReadTable();
}
private void ReadTable()
{
string Constr = "Data Source=Windows身份验证;Initial Catalog=数据库名称;Trusted_Connection=true;";
SqlConnection sqlCon = new SqlConnection(Constr);
string sql = "SELECT * FROM [User]";//sql语句
SqlDataReader reader = null;
try
{
sqlCon.Open();
// 捆绑方法之一,利用BindingSource
SqlCommand cmd = new SqlCommand(sql, sqlCon);
reader = cmd.ExecuteReader();//执行sql语句
//BindingSource:封装窗体的数据源
// BindingSource bs = new BindingSource();//捆绑源
//DataSource:获取或设置连接绑定的数据源
//bs.DataSource = reader; //捆绑执行结果
//dataGridView1.DataSource = bs;
//捆绑方法之二,利用datatable
DataTable table = new DataTable();
table.Load(reader);
dataGridView1.DataSource = table;
}
catch (Exception)
{
MessageBox.Show("获取数据失败");
}
finally
{
reader.Close();
sqlCon.Close();
}
}
}
}