Mapnik整合wxPython

什麼是Mapnik

Mapnik是一款Open source的地圖繪製的程式庫,它可以畫出非常漂亮的地圖,也可以做出像Google Map那樣的地圖,例如這個範例,不過它還算是在開發中,文件還有點不太齊全,因為我想做一套自己的VisualTracert來顯示tracert的router分部在世界的哪裡,那套VisualTracert是商業軟體,要看地圖是要錢的,因此我想弄一個Open source的版本,不過因為還很新,有的應用目前幾乎都是網頁地圖,GUI的例子很少,我花了一點時間,研究如何將地圖畫到wxPython上

程式其實不難,只是mapnik文件都還沒建好,要用dir函數和看原始碼去了解到底有什麼功能可以用,以下就是使用wxPython來畫mapnik地圖的程式

"""
This is a simple wxPython application demonstrates how to
integrate mapnik, it do nothing but draw the map from the World Poplulation XML
example:
http://trac.mapnik.org/wiki/XMLGettingStarted

Victor Lin. (bornstub@gmail.com)
Blog http://blog.ez2learn.com

"""

import wx
import mapnik

class Frame(wx.Frame):
    def __init__(self, *args, **kwargs):
        wx.Frame.__init__(self, size=(800, 500) ,*args, **kwargs)
        self.Bind(wx.EVT_PAINT, self.onPaint)

        self.mapfile = "population.xml"
        self.width = 800
        self.height = 500
        self.createMap()
        self.drawBmp()

    def createMap(self):
        """Create mapnik object

        """
        self.map = mapnik.Map(self.width, self.height)
        mapnik.load_map(self.map, self.mapfile)
        bbox = mapnik.Envelope(mapnik.Coord(-180.0, -75.0), mapnik.Coord(180.0, 90.0))
        self.map.zoom_to_box(bbox)

    def drawBmp(self):
        """Draw map to Bitmap object

        """
        # create a Image32 object
        image = mapnik.Image(self.width, self.height)
        # render map to Image32 object
        mapnik.render(self.map, image)
        # load raw data from Image32 to bitmap
        self.bmp = wx.BitmapFromBufferRGBA(self.width, self.height, image.tostring())

    def onPaint(self, event):
        dc = wx.PaintDC(self)
        memoryDC = wx.MemoryDC(self.bmp)
        # draw map to dc
        dc.Blit(0, 0, self.width, self.height, memoryDC, 0, 0)

if __name__ == '__main__':
    app = wx.App()
    frame = Frame(None, title="wxPython Mapnik Demo By Victor Lin")
    frame.Show()
    app.MainLoop()
wxPython整合Mapnik示範程式畫面

wxPython整合Mapnik示範程式畫面

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One Response to Mapnik整合wxPython

  1. tootoogo says:

    mapnik的东西有点乱,刚接触,头晕目眩,python对我来说也是第一次遇到,好好找到了你这个例子,高手阿