I am learning to use python for gis application. I want to create an application based on wxpython and matplotlib which is able to select shapefile layers from the directory and render them, calculate the distance between points and extract the x y value of the points. In the past I was able to have these functionalities in vb.net based on MapWinGIS tutorial (see attachment), but could not find a way to have it in python. I tried qgis bindings but faced with hard time making python recognize the qgis location. Portability of qgis application is also another holdback.
Khalid_B 0 Newbie Poster
Imports System.Collections
Imports Microsoft.VisualBasic
Public Class MiniGIS
Public sf As New MapWinGIS.Shapefile
Private Sub btnAddLayer_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAddLayer.Click
Dim grd As New MapWinGIS.Grid
Dim img As New MapWinGIS.Image
'enable the users to open any file type.
Dim dlg As New OpenFileDialog
dlg.Filter = "All Files (*.*)|*.*|" & sf.CdlgFilter & _
"|" & grd.CdlgFilter & "|" & img.CdlgFilter
If dlg.ShowDialog() = Windows.Forms.DialogResult.OK Then
'If the user didn't cancel the dialog, try to open the file.
'First, determine what kind it was:
Dim extension As String = _
IO.Path.GetExtension(dlg.FileName).ToLower()
If sf.CdlgFilter.ToLower().Contains(extension) Then
'It's a shapefile
sf.Open(dlg.FileName)
Map.AddLayer(sf, True)
'Zoom to all visible layers
Map.ZoomToMaxExtents()
Return 'Done
ElseIf grd.CdlgFilter.ToLower().Contains(extension) Then
'NOTE: a .tif can be a GeoTIFF (a grid)
'or an image. Check this, if the file
'is a tif:
If dlg.FileName.ToLower().EndsWith("tif") Then
If Not Map.IsTIFFGrid(dlg.FileName) Then
'It's an image, not a grid.
'Open it as an image.
img.Open(dlg.FileName)
Map.AddLayer(img, True)
'Zoom to all visible layers
Map.ZoomToMaxExtents()
Return 'Done
End If
End If
'Open the grid:
grd.Open(dlg.FileName)
'Define a coloring scheme to color this grid:
Dim sch As New MapWinGIS.GridColorScheme
'Use a predefined coloring scheme "Fall Leaves"
sch.UsePredefined(grd.Minimum, grd.Maximum, _
MapWinGIS.PredefinedColorScheme.FallLeaves)
'Convert it to an image that can be displayed:
Dim u As New MapWinGIS.Utils
Dim gridimage As MapWinGIS.Image
gridimage = u.GridToImage(grd, sch)
'Add the generated image to the map:
Map.AddLayer(gridimage, True)
'Zoom to all visible layers
Map.ZoomToMaxExtents()
Return 'Done
ElseIf img.CdlgFilter.ToLower().Contains(extension) Then
'It's a plain image
img.Open(dlg.FileName)
Map.AddLayer(img, True)
'Zoom to all visible layers
Map.ZoomToMaxExtents()
Return 'Done
End If
End If
End Sub
Private Sub btnZoomIn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnZoomIn.Click
Map.CursorMode = MapWinGIS.tkCursorMode.cmZoomIn
End Sub
Private Sub btnZoomOut_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnZoomOut.Click
Map.CursorMode = MapWinGIS.tkCursorMode.cmZoomOut
End Sub
Private Sub btnPan_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnPan.Click
Map.CursorMode = MapWinGIS.tkCursorMode.cmPan
End Sub
Private Sub btnClearLayer_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClearLayer.Click
Dim hndl As Integer
'Get layer handle for layer at position 0
hndl = Map.get_LayerHandle(0)
'Remove layer at position 0 from the map
Map.RemoveLayer(hndl)
End Sub
Private Sub btnFullExtent_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnFullExtent.Click
Map.ZoomToMaxExtents()
End Sub- 1 Contributor
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