在本文中主要是使用ChartDirector的 Python版本来创建出多层级的甘特图，而在此次的示例演示中将会包含两个图层，包含计划和实际情况的甘特图，XYChart.addBoxWhiskerLayer 创建的两个图层，使用BaseBoxLayer.s制作etDataWidth来进行在栏的顶部的图层的宽度的设置，以便它不会挡住底部的图层。

具体示例的源代码如下，和大家一起分享分享：

#!/usr/bin/python
from pychartdir import *# the names of the tasks
labels = ["Market Research", "Define Specifications", "Overall Archiecture","Project Planning", "Detail Design", "Software Development", "Test Plan","Testing and QA", "User Documentation"]# the planned start dates and end dates for the tasks
startDate = [chartTime(2004, 8, 16), chartTime(2004, 8, 30), chartTime(2004, 9, 13),chartTime(2004, 9, 20), chartTime(2004, 9, 27), chartTime(2004, 10, 4),chartTime(2004, 10, 25), chartTime(2004, 11, 1), chartTime(2004, 11, 8)]
endDate = [chartTime(2004, 8, 30), chartTime(2004, 9, 13), chartTime(2004, 9, 27),chartTime(2004, 10, 4), chartTime(2004, 10, 11), chartTime(2004, 11, 8),chartTime(2004, 11, 8), chartTime(2004, 11, 22), chartTime(2004, 11, 22)]# the actual start dates and end dates for the tasks up to now
actualStartDate = [chartTime(2004, 8, 16), chartTime(2004, 8, 27), chartTime(2004, 9,9), chartTime(2004, 9, 18), chartTime(2004, 9, 22)]
actualEndDate = [chartTime(2004, 8, 27), chartTime(2004, 9, 9), chartTime(2004, 9, 27), chartTime(2004, 10, 2), chartTime(2004, 10, 8)]# Create a XYChart object of size 620 x 280 pixels. Set background color to light
# green (ccffcc) with 1 pixel 3D border effect.
c = XYChart(620, 280, 0xccffcc, 0x000000, 1)# Add a title to the chart using 15 points Times Bold Itatic font, with white
# (ffffff) text on a dark green (0x6000) background
c.addTitle("Multi-Layer Gantt Chart Demo", "timesbi.ttf", 15, 0xffffff).setBackground(0x006000)# Set the plotarea at (140, 55) and of size 460 x 200 pixels. Use alternative
# white/grey background. Enable both horizontal and vertical grids by setting their
# colors to grey (c0c0c0). Set vertical major grid (represents month boundaries) 2
# pixels in width
c.setPlotArea(140, 55, 460, 200, 0xffffff, 0xeeeeee, LineColor, 0xc0c0c0, 0xc0c0c0).setGridWidth(2, 1, 1, 1)# swap the x and y axes to create a horziontal box-whisker chart
c.swapXY()# Set the y-axis scale to be date scale from Aug 16, 2004 to Nov 22, 2004, with ticks
# every 7 days (1 week)
c.yAxis().setDateScale(chartTime(2004, 8, 16), chartTime(2004, 11, 22), 86400 * 7)# Add a red (ff0000) dash line to represent the current day
c.yAxis().addMark(chartTime(2004, 10, 8), c.dashLineColor(0xff0000, DashLine))# Set multi-style axis label formatting. Month labels are in Arial Bold font in "mmm
# d" format. Weekly labels just show the day of month and use minor tick (by using
# '-' as first character of format string).
c.yAxis().setMultiFormat(StartOfMonthFilter(), "<*font=arialbd.ttf*>{value|mmm d}",StartOfDayFilter(), "-{value|d}")# Set the y-axis to shown on the top (right + swapXY = top)
c.setYAxisOnRight()# Set the labels on the x axis
c.xAxis().setLabels(labels)# Reverse the x-axis scale so that it points downwards.
c.xAxis().setReverse()# Set the horizontal ticks and grid lines to be between the bars
c.xAxis().setTickOffset(0.5)# Use blue (0000aa) as the color for the planned schedule
plannedColor = 0x0000aa# Use a red hash pattern as the color for the actual dates. The pattern is created as
# a 4 x 4 bitmap defined in memory as an array of colors.
actualColor = c.patternColor([0xffffff, 0xffffff, 0xffffff, 0xff0000, 0xffffff,0xffffff, 0xff0000, 0xffffff, 0xffffff, 0xff0000, 0xffffff, 0xffffff, 0xff0000,0xffffff, 0xffffff, 0xffffff], 4)# Add a box whisker layer to represent the actual dates. We add the actual dates
# layer first, so it will be the top layer.
actualLayer = c.addBoxLayer(actualStartDate, actualEndDate, actualColor, "Actual")# Set the bar height to 8 pixels so they will not block the bottom bar
actualLayer.setDataWidth(8)# Add a box-whisker layer to represent the planned schedule date
c.addBoxLayer(startDate, endDate, plannedColor, "Planned").setBorderColor(SameAsMainColor)# Add a legend box on the top right corner (595, 60) of the plot area with 8 pt Arial
# Bold font. Use a semi-transparent grey (80808080) background.
b = c.addLegend(595, 60, 0, "arialbd.ttf", 8)
b.setAlignment(TopRight)
b.setBackground(0x80808080, -1, 2)# Output the chart
c.makeChart("layergantt.png")

参考资料：ChartDirector教程