关于在winapp c#中绘制烛台图

Question

我正在尝试使用 dot net winforms 应用程序中的图表控件绘制图表。我提供给图表控件的数据源，但在执行代码后控件变为空白，它没有显示任何类型的数据，甚至没有显示 x 和 y 轴。任何了解在 c#winapp 中绘制烛台图的人，如果我做错了，请提供帮助。这是我用来绘制图表的代码。

DataTable dt = new DataTable();
chart1 = new Chart();
SqlConnection con = new SqlConnection();
con.ConnectionString = "connectionString";
con.Open();
string sql = "Select * from tablename ";
SqlCommand cmd = new SqlCommand(sql, con);
cmd.CommandType = CommandType.Text;
SqlDataAdapter sa = new SqlDataAdapter();
sa.SelectCommand = cmd;
sa.Fill(dt);
con.Close();
chart1.Series.Clear();
chart1.Series.Add("new");
chart1.Series["new"].ChartType = SeriesChartType.Candlestick;
chart1.Series["new"].XValueType = ChartValueType.Int32;
chart1.Series["new"].XValueMember = "Xval";
chart1.Series["new"].YValueType = ChartValueType.Int32;
chart1.Series["new"].YValueMembers = "High, Low, Open, Close";
chart1.DataSource = dt;
chart1.DataBind();
dataGridView1.DataSource=dt;
chart1.Series["new"].BorderColor = System.Drawing.Color.Black;
chart1.Series["new"].Color = System.Drawing.Color.Black;
chart1.Series["new"].CustomProperties = "PriceDownColor=Green,
PriceUpColor=Red";
chart1.ChartAreas.Clear();
chart1.ChartAreas.Add("newArea");
chart1.ChartAreas["newArea"].Axes[0].Title = "Date";
chart1.ChartAreas["newArea"].AxisX.LabelStyle.IntervalType = DateTimeIntervalType.Number;
chart1.ChartAreas["newArea"].AxisX.MajorGrid.LineWidth = 1;             
chart1.ChartAreas["newArea"].AxisY.MajorGrid.LineWidth = 1;             
chart1.ChartAreas["newArea"].AxisY.Minimum = 0;             
chart1.ChartAreas["newArea"].AxisY.Maximum = 210;             
chart1.DataManipulator.IsStartFromFirst = false;

Answer 1

从代码中删除以下行。 chart1 = new Chart();