ArcGIS Runtime SDK for iOS(四) ---使用geometry的原始数据重绘折线

2016.4.15 武汉 小雨
by SevenJohs.

• 概述
  通过已经绘制的线的基础上，得到JSON数据，使用geometry的JSON字符串的原始数据重绘折线。

• 内容

  • 绘制出断点折线；
  • 不使用定时器一次性画出；
  • 使用定时器重绘。

• 绘制出断点折线

/** *  绘制线条 */-(void)drawPolyLine{    _pointIndex = 0;    _polyline = nil;    _polylineSymbol = [AGSSimpleLineSymbol simpleLineSymbolWithColor:[UIColor blueColor] width:4];    [self timerDefination];}/** *  更新PolyLine，使其绘制出每隔20个点，绘制出独立的线段。 */-(void)updatePloyline {    if(!_mutPointArr || [_mutPointArr count] <= _pointIndex) {        return;    }    if(!_polyline) {        _polyline = [[AGSMutablePolyline alloc]init];        [_polyline addPathToPolyline];    }//    if(_pointIndex%2 == 0 ){//        [_polyline addPathToPolyline];//        //    }    [_polyline addPointToPath:_mutPointArr[_pointIndex]];    if(_pointIndex>0) {        if(!_graphic) {            [_graphicLayer removeGraphic:_graphic];        }    }    //设置折线属性        _graphic = [AGSGraphic graphicWithGeometry:_polyline symbol:_polylineSymbol attributes:nil infoTemplateDelegate:nil];    [_graphicLayer addGraphic:_graphic];    _pointIndex++;}

• 不使用定时器一次性画出

-(void)drawTrack {    if(!_mapView || ![_mapView loaded]){        return;    }    NSDictionary* geoJSON = [_polyline encodeToJSON];    NSString* jsonStr = [geoJSON description];    _trackDataLine = [AGSPolyline polylineWithJSON:geoJSON];    NSInteger paths = [_trackDataLine numPaths];    AGSMutablePolyline* trackLine = [[AGSMutablePolyline alloc]init];    [trackLine addPathToPolyline];    for (int path = 0; path < paths; path++) {        NSInteger numPntOnPath = [_trackDataLine numPointsInPath:path];        for (int i = 0; i < numPntOnPath; i++) {            AGSPoint* pnt = [_trackDataLine pointOnPath:path atIndex:i];            AGSPoint* newPnt = [AGSPoint pointWithX:pnt.x+0.01 y:pnt.y spatialReference:_mapView.spatialReference];            [trackLine addPointToPath:newPnt];        }        [trackLine addPathToPolyline];    }    if(![trackLine isEmpty]){        AGSSimpleLineSymbol* symbol = [AGSSimpleLineSymbol simpleLineSymbolWithColor:[UIColor purpleColor] width:5];        AGSGraphic* graphic = [AGSGraphic graphicWithGeometry:trackLine symbol:symbol attributes:nil infoTemplateDelegate:nil];        [_graphicLayer addGraphic:graphic];    }    _timer = [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(updateTrack) userInfo:nil repeats:YES];    [_timer fire];}

• 使用定时器重绘。

-(void)updateTrack{    if(_currentPath == 0 && _currentIndex == 0){        [_trackLine addPathToPolyline];    }    NSInteger paths = [_trackDataLine numPaths];    if(_currentPath>= paths){        [self stopTimer];        return;    }    NSInteger numPntOnPath = [_trackDataLine numPointsInPath:_currentPath];    if(_currentIndex >= numPntOnPath){        _currentPath++;        _currentIndex = 0;        [_trackLine addPathToPolyline];        return;    }else{        AGSPoint* pnt = [_trackDataLine pointOnPath:_currentPath atIndex:_currentIndex];        AGSPoint* newPnt = [AGSPoint pointWithX:pnt.x+0.02 y:pnt.y spatialReference:_mapView.spatialReference];        [_trackLine addPointToPath:newPnt];        _currentIndex++;    }    if(![_trackLine isEmpty]){        if(_trackGraphic){            [_graphicLayer removeGraphic:_trackGraphic];        }        AGSSimpleLineSymbol* symbol = [AGSSimpleLineSymbol simpleLineSymbolWithColor:[UIColor orangeColor] width:5];        _trackGraphic = [AGSGraphic graphicWithGeometry:_trackLine symbol:symbol attributes:nil infoTemplateDelegate:nil];        [_graphicLayer addGraphic:_trackGraphic];    }}

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