topic Re: Selection Box in ArcGIS Runtime SDK for iOS Questions

Selection Box

AshrafMemon — Wed, 18 Apr 2012 18:02:25 GMT

Hi there,

Has anyone implemented a selection box to define selection envelop for query on the map? The scenario is:
- User clicks on a query button
- users draws a selection box on the map to define query extent
- user clicks search to search the database.

I have implemented step 1 and 3, need some help (examples or pointers) on step 2.

Thank you,
Ashraf

Re: Selection Box

NimeshJarecha — Wed, 18 Apr 2012 20:13:57 GMT

Ashraf,

You can use Sketch Graphics Layer for step 2 and pass sketch layer's geometry as query geometry parameter. Look at Sketch Layer Sample.

Hope this helps!

Regards,
Nimesh

Re: Selection Box

AshrafMemon — Wed, 18 Apr 2012 20:30:23 GMT

Hi Nimesh,

How do you create a rectangular box using 2 clicks (or dragging) on the map view? I have been playing with the example you pointed out for the last couple of days to figure out the solution and also playing with the identify example, no luck yet. Can you please send me a some clues of a snippet to resolve the issue?

Thanks,
Ashraf

Re: Selection Box

NimeshJarecha — Wed, 18 Apr 2012 20:42:39 GMT

Ashraf,

You want to create a rectangular box using 2 clicks, that's an envelope. You can't sketch an envelope with sketch graphics layer. You should sketch the polygon and use it in the query geometry parameter.

Regards,
Nimesh

Re: Selection Box

AshrafMemon — Wed, 18 Apr 2012 20:56:14 GMT

Hi Nimesh,

Thank you for your responses.

How about using graphics layer with logic to detect 2nd click below, please assume that the below code is written in the successful if condition to detect second click:

        AGSMutablePolygon* sketchPolygon = [[AGSMutablePolygon alloc] initWithSpatialReference:self.mapView.spatialReference];
        self.mappoint2=mappoint;
        NSLog(@"minx,miny,maxx,maxy:%f,%f,%f,%f",self.mappoint1.x,self.mappoint1.y, self.mappoint2.x,self.mappoint2.y);

        [sketchPolygon addRingToPolygon];
        [sketchPolygon addPointToRing:[AGSPoint pointWithX:self.mappoint1.x y:self.mappoint1.y spatialReference:self.mapView.spatialReference]];
        [sketchPolygon addPointToRing:[AGSPoint pointWithX:self.mappoint2.x y:self.mappoint1.y spatialReference:self.mapView.spatialReference]];
        [sketchPolygon addPointToRing:[AGSPoint pointWithX:self.mappoint2.x y:self.mappoint2.y spatialReference:self.mapView.spatialReference]];
        [sketchPolygon addPointToRing:[AGSPoint pointWithX:self.mappoint1.x y:self.mappoint2.y spatialReference:self.mapView.spatialReference]];
        [sketchPolygon addPointToRing:[AGSPoint pointWithX:self.mappoint1.x y:self.mappoint1.y spatialReference:self.mapView.spatialReference]];
       AGSGraphic *graphic;
        AGSSimpleFillSymbol* myFillSymbol = [AGSSimpleFillSymbol simpleFillSymbol];
        myFillSymbol.color = [UIColor colorWithRed:1 green:0 blue:0 alpha:1];

        graphic = [AGSGraphic graphicWithGeometry:sketchPolygon symbol:myFillSymbol attributes:nil infoTemplateDelegate:nil];
       [self.graphicsLayer addGraphic:graphic];

but nothing shows up on the screen, any suggestions on what I am doing wrong?

Thanks,
Ashraf

Re: Selection Box

NimeshJarecha — Wed, 18 Apr 2012 21:02:50 GMT

Nothing shows up because you are making it invisible.

Change,
myFillSymbol.color = [UIColor colorWithRed:1 green:0 blue:0 alpha:1];

To,
myFillSymbol.color = [UIColor colorWithRed:255 green:0 blue:0 alpha:0.5];

Regards,
Nimesh

Re: Selection Box

AshrafMemon — Wed, 18 Apr 2012 21:14:47 GMT

Hi Nimesh,

Sorry that was a mistake, but that didn't solve the problem either. I am attaching the identify demo sample code with the above modification to the code. Can you please check whats wrong?

Thank you,
Ashraf

Re: Selection Box

NimeshJarecha — Wed, 18 Apr 2012 21:32:29 GMT

Just refresh graphics layer after adding the graphic.

[self.graphicsLayer addGraphic:graphic];
[self.graphicsLayer dataChanged]; //add

Regards,
Nimesh

Re: Selection Box

AshrafMemon — Wed, 18 Apr 2012 21:37:30 GMT

just tried that. It didn't work.

Sincerely,
Ashraf Memon
C: 858 405 1484

Re: Selection Box

AshrafMemon — Wed, 18 Apr 2012 21:39:55 GMT

Hi Nimesh,

Is it working on your machine?

Thanks,
Ashraf

Re: Selection Box

NimeshJarecha — Wed, 18 Apr 2012 21:47:18 GMT

Sorry, i just forgot to mention that you were creating graphic with self.mappoint. Change it to use sketchPolygon. See attached project.

[ATTACH=CONFIG]13653[/ATTACH]

Regards,
Nimesh

Re: Selection Box

AshrafMemon — Wed, 18 Apr 2012 21:48:20 GMT

Hi Nimesh,

It worked. Thanks a lot for your help. I am uploading the code if someone else is going through the same problem.

By the way, does ESRI offer a training for iOS development? Or is there developer support for this API?

Thank you,
Ashraf

Re: Selection Box

NimeshJarecha — Wed, 18 Apr 2012 21:52:51 GMT

You're welcome!

Yes, you can go through following free training program. Also, you can contact ESRI Support Services for the development support issues.

http://training.esri.com/gateway/index.cfm?fa=catalog.webCourseDetail&courseID=2051

Regards,
Nimesh

Re: Selection Box

NimeshJarecha — Wed, 18 Apr 2012 21:56:55 GMT

If a post provides the answer to your question, then we encourage you to mark the post as "the answer" by activating the green check mark right of the post. You can also "vote" on posts that you find helpful by clicking the blue caret mark. More information about the ArcGIS Discussion Forums MVP Program found here.

Thank you,
Nimesh