ArcGIS Runtime SDK for iOS(六) --- 空間幾何分析與操作（中）

ArcGIS Runtime SDK for iOS(六) --- 空間幾何分析與操作（中）

2016.4.18 武漢 陰晴
by SevenJohs.

概述
實現緩衝區以及剪下操作。內容：
緩衝區buffer剪下cut

－緩衝區[buffer]： -
續上節內容，緩衝區分析是GIS的基本空間操作功能之一，是指在點、線、面實體的周圍，自動建立的一定寬度的多邊形。
　　例如，某地區有危險品倉庫，要分析一旦倉庫爆炸所涉及的範圍，這就需要進行點緩衝區分析等等。
　　續上節內容，緩衝區分析是GIS的基本空間操作功能之一，是指在點、線、面實體的周圍，自動建立的一定寬度的多邊形。
　　
　　為了在合適的映射位置，使用zoomToEnvelope（縮放/平移映射到指定的包絡圖上）。注意，必須具有相同的spatialReference。

AGSEnvelope* envelope = [self createEnvelope];[_mapView zoomToEnvelope:envelope animated:YES];

–介面：

// Copyright 2016/4/18 by SevenJohs////@property (nonatomic , strong)      IBOutlet AGSMapView *mapView;//開始緩衝區操作按鈕@property (strong, nonatomic) IBOutlet UIButton *btnToStartBuffer;//控制緩衝區的Slider@property (strong, nonatomic) IBOutlet UISlider *bufferDegreeSlider;//選擇繪製類型按鈕（點／線／面）@property (strong, nonatomic) IBOutlet UISegmentedControl *geometrySelectSegment;//重設按鈕@property (strong, nonatomic) IBOutlet UIButton *btnToReset;

-點擊事件操作

#pragma MARK -- Button Click Methods/** *  開始對geometry對象進行緩衝區操作 * */- (IBAction)startBuffer:(id)sender {    AGSGeometry* sketchGeo = [_skechLayer.geometry copy];    AGSSimpleMarkerSymbol* pointSymbol = [[AGSSimpleMarkerSymbol alloc]init];    pointSymbol.color = [UIColor purpleColor];    pointSymbol.style = AGSSimpleMarkerSymbolStyleCircle;    AGSSimpleLineSymbol* lineSymbol = [[AGSSimpleLineSymbol alloc]init];    lineSymbol.color = [UIColor magentaColor];    lineSymbol.width = 4;    //判斷類型，添加特定樣式    AGSGraphic* graphic = [AGSGraphic graphicWithGeometry:sketchGeo symbol:nil attributes:nil infoTemplateDelegate:nil];    if ([sketchGeo isKindOfClass:[AGSPoint class]]) {        graphic.symbol = pointSymbol;    } else {        graphic.symbol = lineSymbol;    }    [_graphicLayer addGraphic:graphic];    //新建立的buffer graphic，並添加    AGSGraphic* newBufferGraphic = [self createBufferGraphicByGeometry:sketchGeo];    //便於重設或移除操作的數組    [_lastBufferArr addObject:newBufferGraphic];    [_graphicLayer addGraphic:newBufferGraphic];    [_skechLayer clear];   }- (IBAction)reset:(id)sender {    _lastBufferArr = [NSMutableArray array];    [_graphicLayer removeAllGraphics];    [_skechLayer clear];}/** *  Slider Value 改變時，同步更新緩衝區數值 * */- (IBAction)slider:(id)sender {    int value = (int)self.bufferDegreeSlider.value;    _bufferDistance = value;    //remove old buffer之後再建立新的bufferGraphic    for (AGSGraphic* oldGraphic in _lastBufferArr) {        [self.graphicLayer removeGraphic:oldGraphic];    }    NSMutableArray* newGraphicsArr = [NSMutableArray array];    for (AGSGraphic* graphic in _graphicLayer.graphics) {        AGSGeometryEngine* geometryEngine = [AGSGeometryEngine defaultGeometryEngine];        AGSGeometry* newGeometry = [geometryEngine bufferGeometry:graphic.geometry byDistance:_bufferDistance];        AGSGraphic* newGraphic = [AGSGraphic graphicWithGeometry:newGeometry symbol:[self setBufferSymbol] attributes:nil infoTemplateDelegate:nil];        [newGraphicsArr addObject:newGraphic];    }    //便於移除    _lastBufferArr = newGraphicsArr;    [_graphicLayer addGraphics:newGraphicsArr];}/** *  選擇對應的geometry，在sketchLayer上繪製 * */- (IBAction)geometryChoose:(id)sender {    switch (_geometrySelectSegment.selectedSegmentIndex) {        case 0:            _skechLayer.geometry = [[AGSMutablePoint alloc]initWithSpatialReference:_mapView.spatialReference];            break;        case 1:            _skechLayer.geometry = [[AGSMutablePolyline alloc]initWithSpatialReference:_mapView.spatialReference];            break;        case 2:            _skechLayer.geometry = [[AGSMutablePolygon alloc]initWithSpatialReference:_mapView.spatialReference];            break;        default:            break;    }    [_skechLayer clear];}

–自訂方法

/** *  設定緩衝區樣式 * *  @return AGSSimpleFillSymbol* 緩衝區樣式 * */-(AGSSimpleFillSymbol*)setBufferSymbol{    AGSSimpleFillSymbol* bufferSymbol = [AGSSimpleFillSymbol simpleFillSymbol];    bufferSymbol.color = [[UIColor brownColor] colorWithAlphaComponent:0.4];    bufferSymbol.outline.color = [UIColor darkGrayColor];    return bufferSymbol;}/** *  使用engine建立buffer graphic * *  @return 新的buffer graphic */-(AGSGraphic*)createBufferGraphicByGeometry:(AGSGeometry*)sketchGeometry{    AGSGeometryEngine* geometryEngine = [AGSGeometryEngine defaultGeometryEngine];    AGSGeometry* newGeometry = [geometryEngine bufferGeometry:sketchGeometry byDistance:_bufferDistance];    AGSGraphic* newGraphic = [AGSGraphic graphicWithGeometry:newGeometry symbol:[self setBufferSymbol] attributes:nil infoTemplateDelegate:nil];    return newGraphic;}/** *  建立envelope */-(AGSEnvelope*)createEnvelope{    AGSSpatialReference *sr = [AGSSpatialReference spatialReferenceWithWKID:SPATIAL_REFERENCE_WKID];    AGSEnvelope* envelope = [AGSEnvelope envelopeWithXmin:X_MIN ymin:Y_MIN xmax:X_MAX ymax:Y_MAX spatialReference:sr];    return envelope;}

–ViewDidLoad & MapViewDidLoad

- (void)viewDidLoad {    [super viewDidLoad];    self.mapView.layerDelegate = self;    self.mapView.touchDelegate = self;    self.mapView.showMagnifierOnTapAndHold = YES;    [self.mapView enableWrapAround];    [self addTiledLayer];    [self addGraphicsLayer];    int value = (int)self.bufferDegreeSlider.value;    _bufferDistance = value;    //建立envelope,中心化目標    AGSEnvelope* envelope = [self createEnvelope];    [_mapView zoomToEnvelope:envelope animated:YES];    _lastBufferArr = [NSMutableArray array];}#pragma mark AGSMapViewLayerDelegate methods-(void) mapViewDidLoad:(AGSMapView*)mapView {    _skechLayer = [AGSSketchGraphicsLayer graphicsLayer];    _skechLayer.geometry = [[AGSMultipoint alloc]initWithSpatialReference:_mapView.spatialReference];    [_mapView addMapLayer:_skechLayer withName:@"Sketch Layer"];    _mapView.touchDelegate = _skechLayer;}

–Result :

===================================================

===================================================
－剪下[Cut]： -

–介面：

// Copyright 2016/4/18 by SevenJohs////@property (nonatomic , strong)      IBOutlet AGSMapView *mapView;//繪製多邊形的按鈕事件@property (strong, nonatomic) IBOutlet UIButton *btnToDrawPolygon;//將草圖圖形複合化，便於觀察@property (strong, nonatomic) IBOutlet UIButton *btnToAdd;//繪製裁剪線條的按鈕事件@property (strong, nonatomic) IBOutlet UIButton *btnToDrawCutLine;//開始裁剪的按鈕事件@property (strong, nonatomic) IBOutlet UIButton *btnToCut;//重設@property (strong, nonatomic) IBOutlet UIButton *btnToReset;

-點擊事件操作

#pragma MARK -- Button Click Methods/** *  開始繪製多邊形 * */- (IBAction)polygonDraw:(id)sender {    _btnToDrawPolygon.enabled = NO;    _btnToAdd.enabled = YES;    _btnToCut.enabled = NO;    _btnToDrawCutLine.enabled = YES;    [_skechLayer clear];    _skechLayer.geometry = [[AGSMutablePolygon alloc]initWithSpatialReference:_mapView.spatialReference];}/** *  為在sketchLayer的圖形繪製複合圖形樣式，進行風格一致性填充 * */- (IBAction)add:(id)sender {    _btnToDrawCutLine.enabled = YES;    _btnToCut.enabled = YES;    AGSGeometry* sketchGeo = [_skechLayer.geometry copy];    AGSGraphic* graphic = [AGSGraphic graphicWithGeometry:sketchGeo symbol:nil attributes:nil infoTemplateDelegate:nil];    //建立CompositeSymbol給新的geometry    AGSCompositeSymbol* compositeSymbol = [AGSCompositeSymbol compositeSymbol];    [compositeSymbol addSymbol:[self setLineSymbol]];    [compositeSymbol addSymbol:[self setFillSymbol]];    graphic.symbol = compositeSymbol;    [_graphicLayer addGraphic:graphic];    [_skechLayer clear];}/** *  繪製線條 * */- (IBAction)cutLineDraw:(id)sender {    _btnToDrawPolygon.enabled = YES;    _btnToCut.enabled = YES;    _btnToAdd.enabled = NO;    _btnToDrawCutLine.enabled = NO;    _skechLayer.geometry = [[AGSMutablePolyline alloc]initWithSpatialReference:_mapView.spatialReference];}/** *  開始裁剪 * */- (IBAction)startToCut:(id)sender {    //建立CompositeSymbol給新的geometry    AGSCompositeSymbol* compositeSymbol = [AGSCompositeSymbol compositeSymbol];    [compositeSymbol addSymbol:[self setLineSymbol]];    [compositeSymbol addSymbol:[self setFillSymbol]];    AGSGeometryEngine* geoEngine = [AGSGeometryEngine defaultGeometryEngine];    NSMutableArray* newGraphicsArr = [NSMutableArray array];    //遍曆已經繪製的圖形    for (AGSGraphic* graphic  in _graphicLayer.graphics) {        NSArray* newGeometryArr = [geoEngine cutGeometry:graphic.geometry withCutter:(AGSPolyline*)_skechLayer.geometry];        if (newGeometryArr.count != 0) {            for (AGSGeometry* geometry in newGeometryArr) {                AGSGraphic* newGraphic = [[AGSGraphic alloc]initWithGeometry:geometry symbol:compositeSymbol attributes:nil infoTemplateDelegate:nil];                [newGraphicsArr addObject:newGraphic];            }        } else {            [newGraphicsArr addObject:graphic];        }    }    [_skechLayer clear];    [_graphicLayer removeAllGraphics];    [_graphicLayer addGraphics:newGraphicsArr];}/** *  重設 * */- (IBAction)reset:(id)sender {    _btnToDrawPolygon.enabled = NO;    _btnToAdd.enabled = YES;    _btnToDrawCutLine.enabled = YES;    _btnToCut.enabled = NO;    [_graphicLayer removeAllGraphics];    [_skechLayer clear];    _skechLayer.geometry = [[AGSMutablePolygon alloc]initWithSpatialReference:_mapView.spatialReference];}

–自訂方法

/** *  設定緩衝區樣式 * *  @return AGSSimpleFillSymbol* 緩衝區樣式 * */-(AGSSimpleFillSymbol*)setBufferSymbol{    AGSSimpleFillSymbol* bufferSymbol = [AGSSimpleFillSymbol simpleFillSymbol];    bufferSymbol.color = [[UIColor brownColor] colorWithAlphaComponent:0.4];    bufferSymbol.outline.color = [UIColor darkGrayColor];    return bufferSymbol;}/** *  使用engine建立buffer graphic * *  @return 新的buffer graphic */-(AGSGraphic*)createBufferGraphicByGeometry:(AGSGeometry*)sketchGeometry{    AGSGeometryEngine* geometryEngine = [AGSGeometryEngine defaultGeometryEngine];    AGSGeometry* newGeometry = [geometryEngine bufferGeometry:sketchGeometry byDistance:_bufferDistance];    AGSGraphic* newGraphic = [AGSGraphic graphicWithGeometry:newGeometry symbol:[self setBufferSymbol] attributes:nil infoTemplateDelegate:nil];    return newGraphic;}/** *  建立envelope */-(AGSEnvelope*)createEnvelope{    AGSSpatialReference *sr = [AGSSpatialReference spatialReferenceWithWKID:SPATIAL_REFERENCE_WKID];    AGSEnvelope* envelope = [AGSEnvelope envelopeWithXmin:X_MIN ymin:Y_MIN xmax:X_MAX ymax:Y_MAX spatialReference:sr];    return envelope;}/** *  底圖載入 */-(void)addTiledLayer{    AGSTiledMapServiceLayer *tiledLayer = [[AGSTiledMapServiceLayer alloc] initWithURL:[NSURL URLWithString:kTiledMapServiceURL]];    [self.mapView addMapLayer:tiledLayer withName:@"Tiled Layer"];}/** *  要素圖層的初始化與載入 */-(void)addGraphicsLayer{    _graphicLayer=[AGSGraphicsLayer graphicsLayer];    _graphicLayer.visible = YES;    [self.mapView addMapLayer:_graphicLayer withName:@"Graphic layer"];}

–ViewDidLoad & MapViewDidLoad

- (void)viewDidLoad {    [super viewDidLoad];    self.mapView.layerDelegate = self;    self.mapView.touchDelegate = self;    self.mapView.showMagnifierOnTapAndHold = YES;    [self.mapView enableWrapAround];    [self addTiledLayer];    [self addGraphicsLayer];    //建立envelope,中心化目標    AGSEnvelope* envelope = [self createEnvelope];    [_mapView zoomToEnvelope:envelope animated:YES];}#pragma mark AGSMapViewLayerDelegate methods-(void) mapViewDidLoad:(AGSMapView*)mapView {    _skechLayer = [AGSSketchGraphicsLayer graphicsLayer];    _skechLayer.geometry = [[AGSMultipoint alloc]initWithSpatialReference:_mapView.spatialReference];    [_mapView addMapLayer:_skechLayer withName:@"Sketch Layer"];    _mapView.touchDelegate = _skechLayer;}

–Result:

===================================================

===================================================
－交集和差集：[Union && Difference]

–介面：

// Copyright 2016/4/18 by SevenJohs////@property (nonatomic , strong)      IBOutlet AGSMapView *mapView;//選擇功能按鈕@property (strong, nonatomic) IBOutlet UISegmentedControl *chooseSegment;//添加圖形並執行操作@property (strong, nonatomic) IBOutlet UIButton *btnToAdd;@property (strong, nonatomic) IBOutlet UIButton *btnToReset;

-點擊事件操作

#pragma MARK -- Button Click Methods- (IBAction)segmentChoose:(UISegmentedControl *)sender {    if (_unionGraphic && _differenceGraphic) {        if (sender.selectedSegmentIndex == 0) {            [_graphicLayer removeAllGraphics];            [_graphicLayer addGraphic:_unionGraphic];        } else {            [_graphicLayer removeAllGraphics];            [_graphicLayer addGraphic:_differenceGraphic];        }    }}- (IBAction)btnToAddNewGeometry:(id)sender {    //得到草圖的圖形，並添加    AGSGeometry* sketchGeometry = [_skechLayer.geometry copy];    AGSGraphic* sketchGraphic = [AGSGraphic graphicWithGeometry:sketchGeometry symbol:nil attributes:nil infoTemplateDelegate:nil];    [_graphicLayer addGraphic:sketchGraphic];    [_skechLayer clear];    //在graphic有兩個圖形的時候，建立engine並進行幾何分析    if(_graphicLayer.graphicsCount == 2){        _btnToAdd.enabled = NO;        AGSGeometryEngine* geoEngine = [AGSGeometryEngine defaultGeometryEngine];        //重新委派對象（copy）        AGSGeometry* geometry1 = [[_graphicLayer.graphics objectAtIndex:0] geometry];        AGSGeometry* geometry2 = [[_graphicLayer.graphics objectAtIndex:1] geometry];        _differenceGraphic = [AGSGraphic graphicWithGeometry:[geoEngine differenceOfGeometry:geometry1 andGeometry:geometry2] symbol:nil attributes:nil infoTemplateDelegate:nil];        _unionGraphic = [AGSGraphic graphicWithGeometry:[geoEngine unionGeometries:[NSArray arrayWithObjects:geometry1,geometry2, nil]] symbol:nil attributes:nil infoTemplateDelegate:nil];        [self segmentChoose:_chooseSegment];    }}- (IBAction)btnToResetData:(id)sender {    [_graphicLayer removeAllGraphics];    [_skechLayer clear];    _unionGraphic = nil;    _differenceGraphic = nil;    _btnToAdd.enabled = YES;}

–自訂方法

#pragma mark Privated Method-(void)addTiledLayer{    AGSTiledMapServiceLayer *tiledLayer = [[AGSTiledMapServiceLayer alloc] initWithURL:[NSURL URLWithString:kTiledMapServiceURL]];    [self.mapView addMapLayer:tiledLayer withName:@"Tiled Layer"];}-(void)addGraphicsLayer{    //渲染    AGSCompositeSymbol* compositeSymbol = [AGSCompositeSymbol compositeSymbol];    [compositeSymbol addSymbol:[self setLineSymbol]];    [compositeSymbol addSymbol:[self setFillSymbol]];    [compositeSymbol addSymbol:[self setPointSymbol]];    AGSSimpleRenderer* simpleRenderer = [AGSSimpleRenderer simpleRendererWithSymbol:compositeSymbol];    _graphicLayer = [AGSGraphicsLayer graphicsLayer];    _graphicLayer.visible = YES;    _graphicLayer.renderer = simpleRenderer;    [_mapView addMapLayer:_graphicLayer withName:@"Graphics Layer"];}-(AGSSimpleLineSymbol *)setLineSymbol{    AGSSimpleLineSymbol* lineSymbol = [[AGSSimpleLineSymbol alloc]init];    lineSymbol.color = [UIColor brownColor];    lineSymbol.width = 4;    return lineSymbol;}-(AGSSimpleFillSymbol *)setFillSymbol{    AGSSimpleFillSymbol* innerSymbol = [AGSSimpleFillSymbol simpleFillSymbol];    innerSymbol.color = [[UIColor greenColor]colorWithAlphaComponent:0.40];    innerSymbol.outline = nil;    return innerSymbol;}-(AGSSimpleMarkerSymbol*)setPointSymbol{    AGSSimpleMarkerSymbol* pointSymbol = [[AGSSimpleMarkerSymbol alloc]init];    pointSymbol.color = [UIColor orangeColor];    pointSymbol.style = AGSSimpleMarkerSymbolStyleCircle;    return pointSymbol;}

–ViewDidLoad & MapViewDidLoad

- (void)viewDidLoad {    [super viewDidLoad];    self.mapView.layerDelegate = self;    self.mapView.callout.delegate = self;    self.mapView.touchDelegate = self;    self.mapView.showMagnifierOnTapAndHold = YES;    [self.mapView enableWrapAround];    [self addTiledLayer];    [self addGraphicsLayer];}#pragma mark AGSMapViewLayerDelegate methods-(void) mapViewDidLoad:(AGSMapView*)mapView {    _skechLayer = [AGSSketchGraphicsLayer graphicsLayer];    _skechLayer.geometry = [[AGSMutablePolygon alloc]initWithSpatialReference:_mapView.spatialReference];    [_mapView addMapLayer:_skechLayer withName:@"Sketch Layer"];    _mapView.touchDelegate = _skechLayer;    _skechLayer.geometry = [[AGSMutablePolygon alloc]initWithSpatialReference:_mapView.spatialReference];}

–Result:

END。