c# - 在c#中删除一行表单DataGridView和数据库后如何刷新DataGridView？

Question

删除stockdataGridView1的选定行后，它不会刷新。 请告诉我删除选定行后如何刷新。 我需要重新打开表单或添加另一个刷新按钮吗？

private void stockdataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
{

}

private void Report_Load(object sender, EventArgs e)
{
    string connectionString = @"Server=.\SQLEXPRESS; Database = stock; integrated Security = true";
    SqlConnection connection = new SqlConnection(connectionString);
    string query = "SELECT * FROM stocktable1";
    SqlCommand command = new SqlCommand(query, connection);
    connection.Open();
    SqlDataReader reader = command.ExecuteReader();
    List<Stock> stocks = new List<Stock>();
    while (reader.Read())
    {
        Stock stock = new Stock();
        stock.id = (int)reader["id"];
        stock.gsm = reader["gsm"].ToString();
        stock.color = reader["color"].ToString();
        stock.size = reader["size"].ToString();
        stock.yard = reader["yard"].ToString();
        stock.meter = reader["meter"].ToString();
        stock.quantity = reader["quantity"].ToString();
        stock.supplier = reader["supplier"].ToString();
        stock.purpose = reader["purpose"].ToString();
        stock.chalanno = reader["chalanno"].ToString();
        stocks.Add(stock);
    }
    reader.Close();
    connection.Close();
    stockdataGridView1.DataSource = stocks;
}

private void deletebutton_Click(object sender, EventArgs e)
{

    int id = (int)stockdataGridView1.CurrentRow.Cells["id"].Value;
    string connectionString = @"Server=.\SQLEXPRESS; Database = stock; integrated Security = true";
    SqlConnection connection = new SqlConnection(connectionString);
    string query = "delete from stocktable1 where id=" + id;
    SqlCommand command = new SqlCommand(query, connection);
    connection.Open();
    int rowaffected = command.ExecuteNonQuery();
    connection.Close();
    stockdataGridView1.Update();
    stockdataGridView1.Refresh();  

    MessageBox.Show("deleted");
}

} }

Answer 1

要在添加或删除行后刷新网格，您需要再次设置网格的DataSource属性，然后调用DataGridView对象上的DataBind()方法。 在您的情况下，您可以在类级别定义数据源，即您的List<Stock>对象，并在捕获 Delete 按钮的单击事件时，将数据源重新绑定到数据网格视图，如前所述。

Answer 2

添加我在下面创建的新方法并调整原始方法，如下所示，该方法应该在您加载网格和删除网格时被调用。

正如我在评论中提到的，您的代码需要调整，使用更频繁的功能。

        private void stockdataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {

        }

        private void UpdateAndLoad()
        {

            string connectionString = @"Server=.\SQLEXPRESS; Database = stock; integrated Security = true";
            SqlConnection connection = new SqlConnection(connectionString);
            string query = "SELECT * FROM stocktable1";
            SqlCommand command = new SqlCommand(query, connection);
            connection.Open();
            SqlDataReader reader = command.ExecuteReader();
            List<Stock> stocks = new List<Stock>();
            while (reader.Read())
            {
                Stock stock = new Stock();
                stock.id = (int)reader["id"];
                stock.gsm = reader["gsm"].ToString();
                stock.color = reader["color"].ToString();
                stock.size = reader["size"].ToString();
                stock.yard = reader["yard"].ToString();
                stock.meter = reader["meter"].ToString();
                stock.quantity = reader["quantity"].ToString();
                stock.supplier = reader["supplier"].ToString();
                stock.purpose = reader["purpose"].ToString();
                stock.chalanno = reader["chalanno"].ToString();
                stocks.Add(stock);
            }
            reader.Close();
            connection.Close();
            stockdataGridView1.DataSource = stocks;
        }

        private void Report_Load(object sender, EventArgs e)
        {
            UpdateAndLoad();
        }

        private void deletebutton_Click(object sender, EventArgs e)
        {

            int id = (int)stockdataGridView1.CurrentRow.Cells["id"].Value;
            string connectionString = @"Server=.\SQLEXPRESS; Database = stock; integrated Security = true";
            SqlConnection connection = new SqlConnection(connectionString);
            string query = "delete from stocktable1 where id=" + id;
            SqlCommand command = new SqlCommand(query, connection);
            connection.Open();
            int rowaffected = command.ExecuteNonQuery();
            connection.Close();
            stockdataGridView1.Update();
            stockdataGridView1.Refresh();  

            MessageBox.Show("deleted");
            UpdateAndLoad();
        }