C#

void PlotChart()
        {
            try
            {
                // Check if label86.Text can be converted to an integer
                if (!int.TryParse(label86.Text.Trim(), out int rawDataOrder))
                {
                    MessageBox.Show("Invalid RawDataOrder value. Please enter a valid integer.", "Error PlotChart", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    return; // Exit the method
                }

                using (SqlConnection connection = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True"))
                {
                    using (SqlCommand command = new SqlCommand("SELECT * FROM SerialDataNIBP WHERE RawDataOrder = @RawDataOrder", connection))
                    {
                        // Open the connection if it's not already open
                        if (connection.State != ConnectionState.Open)
                        {
                            connection.Open();
                        }

                        command.Parameters.AddWithValue("@RawDataOrder", rawDataOrder);

                        using (SqlDataReader reader = command.ExecuteReader())
                        {
                            // Check if any data is returned
                            if (!reader.HasRows)
                            {
                                MessageBox.Show("No data found for the given RawDataOrder.", "Error PlotChart", MessageBoxButtons.OK, MessageBoxIcon.Error);
                                return; // Exit the method
                            }

                            chart1.Series.Clear();

                            Series PulseCh1 = new Series("Series11");
                            Series PressureCh1 = new Series("Series12");

                            PulseCh1.ChartType = SeriesChartType.Spline;
                            PressureCh1.ChartType = SeriesChartType.Spline;

                            PulseCh1.Color = Color.Blue;
                            PressureCh1.Color = Color.Orange;

                            while (reader.Read())
                            {
                                var id = reader.GetInt32(0);
                                var value11 = reader.GetInt32(1);
                                var value12 = reader.GetInt32(8);

                                PulseCh1.Points.AddXY(id, value11);
                                PressureCh1.Points.AddXY(id, value12);
                            }

                            chart1.Series.Add(PulseCh1);
                            chart1.Series.Add(PressureCh1);

                            chart1.Titles.Clear();
                            chart1.Titles.Add(new Title("Channel 1"));

                            // Uncomment the line below if you want to refresh the chart display
                            chart1.Update();
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "Error PlotChart", MessageBoxButtons.OK, MessageBoxIcon.Error);

                // Log the exception or handle it based on your application's requirements
            }
        }

Iskander12345 wrote:

C#

string query = $"SELECT * FROM Data WHERE RawDataOrder = {Convert.ToInt32(label86.Text.Trim())}";

const string query = "SELECT * FROM Data WHERE RawDataOrder = @RawDataOrder";
using (SqlCommand command = new SqlCommand(query, connection))
{
    command.Parameters.AddWithValue("@RawDataOrder", Convert.ToInt32(label86.Text.Trim()));
    ...

string query = $"SELECT * FROM Data WHERE RawDataOrder = {Convert.ToInt32(label86.Text.Trim())}";

string query = "SELECT * FROM Data WHERE RawDataOrder = @orderId";

// Parse the UI value. Why you're using a label to "store" data
// used in your busniess rules is beyond my comprehension.
int orderId;

if (int.TryParse(label86.Text.Trim(), out orderId))
{
    // The parse worked! If execution gets to the next statement, orderId
    // has a valid value. Since the value is sitting in a variable, you
    // can now debug the code to see its value and what is being passed
    // to the SQL query.

    // Build the SQL Command
    using (SqlConnection conn = new SqlConnection("... connection string ..."))
    {

        using (SqlCommand comm = new SqlCommand(query, conn))
        {
            SqlParameter orderIdParam = new SqlParameter("@orderId", SqlDbType.Int);
            orderIdParam.Value = orderId;
            comm.Parameters.Add(orderIdParam);

            // You forgot to open the connection
            conn.Open();
            using (SqlDataReader reader = comm.ExecuteReader())
            {
                while (reader.Read())
                {
                    ...
                }
            }
        }
    }
}
else
{
    // The parse failed! You might want to tell the user about that.
    // If execution gets to here, the parse failed and you do not have a valid
    // orderId value.
}

Quote:

int.TryParse(label86.Text.Trim()

Iskander12345 wrote:

but when I use this filter, it often leads to blank chart

Try {
  MyStuff();
} catch (etc) { // etc. }

private decimal Highest(int bar, ValueDataSeries src, int length)
{
    if (bar < length)
        return 0.0m;

    decimal res = decimal.MinValue;

    for (int index = bar; index >= bar - (length - 1); index--)
    {
        if (src[index] > res)
            res = src[index];
    }

    return res;
}