Menata gaya contoh fitur data

Halaman ini menunjukkan cara mengakses set data secara terprogram dan menata gaya fiturnya, dan membahas contoh gaya visual untuk fitur data berdasarkan titik, poligon, dan geometri polyline.

Gaya visual berbasis data untuk set data merender fitur data berdasarkan koordinat lintang dan bujur yang diberikan dari file data geospasial yang digunakan untuk membuat set data.

Contoh gaya visual data titik

Contoh ini menunjukkan pendekatan untuk menata gaya fitur data berbasis geometri titik.

Tentang set data

Set data yang digunakan dalam contoh ini adalah hasil dari Survei tupai tahun 2018 di Central Park, New York City. Dalam kutipan berikut dari file data CSV, kita melihat bahwa kolom x dan y digunakan untuk geografi; kolom LatLng disertakan, tetapi tidak digunakan dalam karena {i>dataset<i} hanya mendukung Format WKT jika kolom bernama WKT. Untuk informasi selengkapnya tentang format yang didukung untuk mengetahui lokasi, lihat Persyaratan CSV.

{i>Dataset<i} sensus tupai berisi berbagai titik data yang berbeda yang berkaitan dengan warna bulu dan perilaku tupai yang diamati (pastikan untuk menggulir secara horizontal untuk melihat semuanya).

Menata gaya fitur data titik

Kode dalam contoh ini mengambil pendekatan penataan gaya warna isian dan warna goresan untuk setiap titik berdasarkan CombinationofPrimaryandHighlightColor , yang menggabungkan warna bulu utama dan sekunder untuk masing-masing tupai.

let mapView = GMSMapView(frame: .zero, mapID: GMSMapID(identifier: "YOUR_MAP_ID"), camera: GMSCameraPosition(latitude: 40.7, longitude: -74.0, zoom: 12))

let layer = mapView.datasetFeatureLayer(of: "YOUR_DATASET_ID")

// Define a point style with fill and radius.
// Apply the style to the datasets features.
layer.style = { feature in
    switch(feature.datasetAttributes["CombinationofPrimaryandHighlightColor"]){
      case "Black+"  :
        let style = MutableFeatureStyle()
        style.fillColor = .black;
        style.pointRadius = 8;
        return style
      case "Cinnamon+"  :
        let style = MutableFeatureStyle()
        style.fillColor = UIColor(red: 139/255, green: 0, blue: 0, alpha: 1);
        style.pointRadius = 8;
        return style
      ...
      default :
        let style = MutableFeatureStyle()
        style.fillColor = .yellow;
        style.pointRadius = 8;
        return style
    }
}

GMSMapView *mapView = [GMSMapView mapWithFrame:CGRectZero mapID:[GMSMapID mapIDWithIdentifier:@"MAP_ID"] camera:[GMSCameraPosition cameraWithLatitude: 40.7 longitude: -74.0 zoom:12]];

GMSDatasetFeatureLayer *layer = [mapView datasetFeatureLayerOfDatasetID:@"YOUR_DATASET_ID"];

// Define a point style with fill and radius.
// Apply the style to the datasets features.
layer.style = ^(GMSDatasetFeature *feature) {
  NSString *attrib = feature.datasetAttributes[@"CombinationofPrimaryandHighlightColor"];
  if ([attrib isEqualToString:@"Black+"])  {
    GMSMutableFeatureStyle *style = [GMSMutableFeatureStyle style];
    style.fillColor = [UIColor blackColor];
    style.pointRadius = 8;
    return style;
  } else if([attrib isEqualToString:@"Cinnamon+"]) {
    GMSMutableFeatureStyle *style = [GMSMutableFeatureStyle style];
    style.fillColor = [UIColor colorWithRed:139.0f/255.0f
                                      green:0.0f
                                        blue:0.0f
                                      alpha:1.0f];
    style.pointRadius = 8;
    return style;
  }
  ...
  else {
    GMSMutableFeatureStyle *style = [GMSMutableFeatureStyle style];
    style.fillColor = [UIColor yellowColor];
    style.pointRadius = 8;
    return style;
  }
};

Contoh gaya visual data poligon

Contoh ini menunjukkan pendekatan untuk menata gaya fitur data berbasis geometri poligon.

Tentang set data

{i>Dataset<i} yang digunakan dalam contoh ini menggambarkan taman di New York City. Kutipan berikut yang berasal dari file GeoJSON set data menunjukkan entri fitur yang representatif.

{
  "type": "Feature",
  "properties": {
    "jurisdiction": "DPR",
    "mapped": "False",
    "zipcode": "11356",
    "acres": "0.05",
    "location": "College Pl., College Pt. Blvd., bet. 11 Ave. and 12 Ave.",
    "nys_assembly": "27",
    "councildistrict": "19",
    "url": "http://www.nycgovparks.org/parks/Q042/",
    "typecategory": "Triangle/Plaza",
    "us_congress": "14",
    "eapply": "Poppenhusen Park",
    "parentid": "Q-07",
    "gispropnum": "Q042",
    "retired": "false",
    "communityboard": "407",
    "objectid": "6248",
    "globalid": "F4810079-CBB9-4BE7-BBFA-B3C0C35D5DE5",
    "name311": "Poppenhusen Park",
    "department": "Q-07",
    "pip_ratable": "true",
    "subcategory": "Sitting Area/Triangle/Mall",
    "precinct": "109",
    "permit": "true",
    "acquisitiondate": null,
    "omppropid": "Q042",
    "gisobjid": "100000301",
    "signname": "Poppenhusen Park",
    "address": null,
    "permitparent": "Q-07",
    "class": "PARK",
    "nys_senate": "11",
    "permitdistrict": "Q-07",
    "borough": "Q",
    "waterfront": "false"
  },
  "geometry": {
    "type": "MultiPolygon",
    "coordinates": [
      [
        [
          [
            -73.84575702371716,
            40.78796240884273
          ],
          [
            -73.84593393292693,
            40.78796857347548
          ],
          [
            -73.84577256469657,
            40.787651355629556
          ],
          [
            -73.84575702371716,
            40.78796240884273
          ]
        ]
      ]
    ]
  }
},

Menata gaya fitur data poligon

Kode dalam contoh ini menerapkan pewarnaan khusus untuk fitur data yang terkait dengan typecategory dari "Undeveloped" atau "Parkway", dan mewarnai semua fitur lainnya dengan warna hijau.

let mapView = GMSMapView(frame: .zero, mapID: GMSMapID(identifier: "YOUR_MAP_ID"), camera: GMSCameraPosition(latitude: 40.7, longitude: -74.0, zoom: 12))

let layer = mapView.datasetFeatureLayer(of: "YOUR_DATASET_ID")

// Define a polygon style with fill and stroke.
// Apply the style to the datasets features.
layer.style = { feature in
  switch(feature.datasetAttributes["typecategory"]){
    case "Undeveloped"  :
      let style = MutableFeatureStyle()
      style.fillColor = .blue.withAlphaComponent(0.3);
      style.strokeColor = .blue;
      style.strokeWidth = 2.0;
      return style
    case "Parkway"  :
      let style = MutableFeatureStyle()
      style.fillColor = .red.withAlphaComponent(0.3);
      style.strokeColor = .red;
      style.strokeWidth = 2.0;
      return style
    default :
      let style = MutableFeatureStyle()
      style.fillColor = .green.withAlphaComponent(0.3);
      style.strokeColor = .green;
      style.strokeWidth = 2.0;
      return style
  }
}

GMSMapView *mapView = [GMSMapView mapWithFrame:CGRectZero mapID:[GMSMapID mapIDWithIdentifier:@"MAP_ID"] camera:[GMSCameraPosition cameraWithLatitude: 40.7 longitude: -74.0 zoom:12]];

GMSDatasetFeatureLayer *layer = [mapView datasetFeatureLayerOfDatasetID:@"YOUR_DATASET_ID"];

// Define a polygon style with fill and stroke.
// Apply the style to the datasets features.
layer.style = ^(GMSDatasetFeature *feature) {
  NSString *attrib = feature.datasetAttributes[@"typecategory"];
  if ([attrib isEqualToString:@"Undeveloped"]) {
        GMSMutableFeatureStyle *style = [GMSMutableFeatureStyle style];
        style.fillColor = [[UIColor blueColor] colorWithAlphaComponent:0.3];
        style.strokeColor = [UIColor blueColor];
        style.strokeWidth = 2.0;
        return style;
  } else if([attrib isEqualToString:@"Parkway"]) {
        GMSMutableFeatureStyle *style = [GMSMutableFeatureStyle style];
        style.fillColor = [[UIColor redColor] colorWithAlphaComponent:0.3];
        style.strokeColor = [UIColor redColor];
        style.strokeWidth = 2.0;
        return style;
  } else {
        GMSMutableFeatureStyle *style = [GMSMutableFeatureStyle style];
        style.fillColor = [[UIColor greenColor] colorWithAlphaComponent:0.3];
        style.strokeColor = [UIColor greenColor];
        style.strokeWidth = 2.0;
        return style;
    }
  };

Contoh gaya visual data polyline

Contoh ini menunjukkan pendekatan untuk menata gaya fitur data berbasis geometri polyline.

Tentang set data

{i>Dataset<i} yang digunakan dalam contoh ini menunjukkan jembatan di area Seattle. Kutipan berikut yang berasal dari file GeoJSON set data menunjukkan entri fitur yang representatif.

{
  "type": "Feature",
  "properties": {
      "OBJECTID": 1,
      "COMPTYPE": 66,
      "COMPKEY": 515774,
      "HANSEGKEY": 489781,
      "UNITID": "BRG-935",
      "UNITTYPE": " ",
      "BRGUNITID": "BRG-935",
      "UNITDESC_BRG": "YALE AVE BR REV LANE OC                                                                                                                                                                                                                                        ",
      "UNITDESC_SEG": "HOWELL ST ON RP BETWEEN HOWELL ST AND I5 SB                                                                                                                                                                                                                    ",
      "INSTDATE": null,
      "EXPDATE": null,
      "STATUS": " ",
      "STATUSDT": null,
      "CONDITION": " ",
      "CONDDT": null,
      "OWN": " ",
      "LSTVERIFY": null,
      "MAINTBY": " ",
      "ADDBY": "GARCIAA",
      "ADDDTTM": "2010-01-21T00:00:00Z",
      "MODBY": null,
      "MODDTTM": null,
      "BR_NBR": 935,
      "BR_CODE": " 935",
      "BR_TYPE": "ST",
      "BR_NAME": "YALE AVE BR REV LANE OC",
      "BR_FACILITIES": "YALE AVE-SR 5 ON RAMP",
      "BR_FEATURES": "SR 5 REV LANE",
      "BR_RATING": 0,
      "BR_INSET": 1,
      "BR_GEO": "DT",
      "BR_OWNER": "DOT",
      "BR_OWNER_NAME": "State of Washington",
      "GEOBASID": 0,
      "XGEOBASID": 0,
      "GISSEGKEY": 489781,
      "EARTHQUAKE_RESPONSE_TEAM": " ",
      "SHAPE_Length": 220.11891836147655
  },
  "geometry": {
      "type": "LineString",
      "coordinates": [
          [
              -122.329201929090928,
              47.616910448708538
          ],
          [
              -122.329206483407461,
              47.616976719821004
          ],
          [
              -122.32921802149356,
              47.617042137515213
          ],
          [
              -122.329236413912909,
              47.617105967923777
          ],
          [
              -122.329261454336034,
              47.617167494985758
          ],
          [
              -122.329292861855023,
              47.617226028479571
          ],
          [
              -122.329330284134699,
              47.617280911766009
          ],
          [
              -122.329373301365223,
              47.617331529154569
          ],
          [
              -122.329421430971635,
              47.617377312810319
          ],
          [
              -122.329474133027375,
              47.617417749124023
          ],
          [
              -122.32953081631139,
              47.617452384473893
          ]
      ]
  }
},

Menata gaya fitur data polyline

Cuplikan berikut menerapkan gaya yang sama secara langsung ke semua fitur data.

// Define a style with green fill and stroke.
// Apply the style to the datasets features.
layer.style = { feature in
  let style = MutableFeatureStyle()
  style.fillColor = .green.withAlphaComponent(0.5);
  style.strokeColor = [UIColor greenColor];
  style.strokeWidth = 2.0;
  return style
}

// Define a style with green fill and stroke.
// Apply the style to the datasets features.
layer.style = ^(GMSDatasetFeature *feature) {
  GMSMutableFeatureStyle *style = [GMSMutableFeatureStyle style];
  style.fillColor = [[UIColor greenColor] colorWithAlphaComponent:0.5];
  style.strokeColor = [UIColor greenColor];
  style.strokeWidth = 2.0;
  return style;
};