C＃：Foreach DataGridViewRow循环不按预期在面板中绘制图形

Question

我有以下 code1 ，它可以按预期完成从DataTable中绘制甘特图。但是，当我为我的DataGridView点击事件 code2 使用相同的foreach循环时，它无法正常工作 img2 - 我希望甘特图对应于DataGridView表，按照 IMG1 即可。请不要在 code2 中更改为foreach循环，以便它使用DataGridView语法。

任何想法？

备受赞赏

代码1

// Draw Gantt Chart
        foreach (DataRow rowCapPlan in dtCapPlan.Rows)
        {
            id = rowCapPlan["Program ID"].ToString();

            foreach (DataRow rowMilestone in dtMilestones.Rows)
            {
                if (id == rowMilestone["Program ID"].ToString())
                {
                    // calculate space in days from todays date and the milestone date
                    msDate = Convert.ToDateTime(rowMilestone["Milestone Date"]);
                    msTimespan = msDate - calDate;
                    msIntDate = (int)msTimespan.TotalDays + 1;
                    tTimespan = tDate - calDate;
                    tIntDate = (int)tTimespan.TotalDays + 1;
                    ganttPlotSpace = msIntDate - tIntDate;

                    // Draw each milestone or gateway which is not yet complete
                    if (rowMilestone["% Complete"].ToString() != "100")
                    {
                        taskname = rowMilestone["Task Name"].ToString();
                        if (taskname == "Gateway 1" || taskname == "Gateway 2" || taskname == "Gateway 3" || taskname == "Gateway 4" || taskname == "Gateway 5")
                        {
                            Rectangle gw = new Rectangle(startx + ganttPlotSpace, starty - 4, 2, 11);
                            ganttGraphics.DrawRectangle(gwPen, gw);
                            ganttGraphics.FillRectangle(gwBrush, gw);
                        }
                        else
                        {
                            Rectangle ms = new Rectangle(startx + ganttPlotSpace + 1, starty, 2, 2);
                            ganttGraphics.DrawRectangle(msPen, ms);
                            ganttGraphics.FillRectangle(msBrush, ms);
                        }
                        ganttGraphics.DrawLine(linePen, startx - 10, starty - 11, pnlGantt.Right, starty - 11);
                    }
                }
            }
            starty = starty + 22;
        }
        ganttGraphics.DrawLine(linePen, startx - 10, starty + 11, pnlGantt.Right, starty + 11);

IMG1

码2

private void dataCapPlan_ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
    {

        int startx = 10;
        int starty = 78;
        pnlGantt.Controls.Clear();
        Graphics ganttGraphics = pnlGantt.CreateGraphics();
        // Draw Gantt Chart
        foreach (DataGridViewRow rowCapPlan in dataCapPlan.Rows)
        {
            id = rowCapPlan.Cells[0].ToString();

            foreach (DataGridViewRow rowMilestone in dataMilestones.Rows)
            {
                if (id == rowMilestone.Cells[0].ToString())
                {
                    // calculate space in days from todays date and the milestone date
                    msDate = Convert.ToDateTime(rowMilestone.Cells[2].Value);
                    msTimespan = msDate - calDate;
                    msIntDate = (int)msTimespan.TotalDays + 1;
                    tTimespan = tDate - calDate;
                    tIntDate = (int)tTimespan.TotalDays + 1;
                    ganttPlotSpace = msIntDate - tIntDate;

                    // Draw each milestone or gateway which is not yet complete
                    if (rowMilestone.Cells[3].ToString() != "100")
                    {
                        taskname = rowMilestone.Cells[1].ToString();
                        if (taskname == "Gateway 1" || taskname == "Gateway 2" || taskname == "Gateway 3" || taskname == "Gateway 4" || taskname == "Gateway 5")
                        {
                            Rectangle gw = new Rectangle(startx + ganttPlotSpace, starty - 4, 2, 11);
                            ganttGraphics.DrawRectangle(gwPen, gw);
                            ganttGraphics.FillRectangle(gwBrush, gw);
                        }
                        else
                        {
                            Rectangle ms = new Rectangle(startx + ganttPlotSpace + 1, starty, 2, 2);
                            ganttGraphics.DrawRectangle(msPen, ms);
                            ganttGraphics.FillRectangle(msBrush, ms);
                        }
                        ganttGraphics.DrawLine(linePen, startx - 10, starty - 11, pnlGantt.Right, starty - 11);
                    }
                }
            }
            starty = starty + 22;
        }
        ganttGraphics.DrawLine(linePen, startx - 10, starty + 11, pnlGantt.Right, starty + 11);
    }

IMG2