string cedian = textBox1.Text;
string sql = "SELECT upid,RegAddr,StatusID,IOTime,DataFlag AS 值 FROM deil WHERE upid = 3316";
string sqlStr = sql.ToString();
SqlDataAdapter myDataAdapter;
DataSet myDataSet = new DataSet();
myDataAdapter = new SqlDataAdapter(sqlStr, detail);
//Fill 方法会执行一系列操作 connection.open command.reader 等等
//反正到最后就把 sql语句执行一遍,然后把结果集插入到 ds 里.
myDataAdapter.Fill(myDataSet);
DataTable dt = myDataSet.Tables[0];
foreach (DataRow row in dt.Rows)
{
byte[] value = smethod_10(row["值"].ToString());
double num3 = BitConverter.ToDouble(value, 0);
DataRow dataRow3 = dt.NewRow();
dataRow3["值"] = num3;
dt.Rows.Add(dataRow3);
myDataAdapter.Fill(myDataSet, "test");
dataGridView2.DataSource = myDataSet.Tables["test"];
}
显示错误 System.InvalidOperationException:“集合已修改;枚举操作可能无法执行。” 该怎么写呢?
设置DataGridView
的DataSource
属性,示例如下:
using System.Data;
using System.Data.SqlClient;
namespace WinFormsApp1
{
public partial class Form3 : Form
{
public Form3()
{
InitializeComponent();
}
private void Form3_Load(object sender, EventArgs e)
{
using var connection = new SqlConnection("Server=(localdb)\\mssqllocaldb;Integrated Security=true;Database=Demo");
var query = "Select * From Customer";
var sqlCommand = new SqlCommand(query, connection);
connection.Open();
var reader = sqlCommand.ExecuteReader();
if (reader.HasRows)
{
var dt = new DataTable();
dt.Load(reader);
dataGridView1.DataSource = dt;
}
}
}
}
数据库中的示例数据如下:
示例程序运行效果如下:
数据绑定到itemsouece就可以了了。