設定地圖項目樣式

選取平台： Android iOS JavaScript

如要將樣式套用至資料地圖項目，請在資料集地圖項目圖層將 style 屬性設為 google.maps.FeatureStyleFunction (可包含樣式邏輯) 或是設為 google.maps.FeatureStyleOptions (統一圖層中所有地圖項目的樣式)。資料地圖項目可套用的樣式包括填滿 (顏色、不透明度)、筆劃 (顏色、不透明度、筆劃粗細) 和直徑 (點)。本頁說明如何以程式輔助方式存取資料集，並設定地圖項目樣式。此外，也會列舉幾個範例，逐步講解如何依據點、多邊形和折線幾何圖形，設定資料地圖項目樣式。

建立資料集時使用的地理空間資料檔案含有經緯度座標，資料集的資料導向樣式會根據這些座標資訊，算繪資料地圖項目。

資料地圖項目屬性

您可以使用地圖項目樣式函式，存取資料集內的所有資料。如要取得資料地圖項目屬性，請先取得資料集地圖項目 (內含資料集的所有資料)，再取得需要的特定資料屬性，如下所示：

TypeScript

// Get the dataset feature, so we can work with all of its attributes.
const datasetFeature = params.feature;
// Get all of the needed dataset attributes.
const furColors = datasetFeature.datasetAttributes['CombinationofPrimaryandHighlightColor'];
index.ts

JavaScript

// Get the dataset feature, so we can work with all of its attributes.
const datasetFeature = params.feature;
// Get all of the needed dataset attributes.
const furColors = datasetFeature.datasetAttributes['CombinationofPrimaryandHighlightColor'];
index.js

地圖項目樣式選項

您可透過地圖項目樣式選項定義資料地圖項目圖層的樣式，例如設定多邊形的填滿和筆劃樣式，或是點的顏色和直徑樣式。使用地圖項目的 style 屬性，即可直接套用地圖項目樣式選項，如下例所示：

TypeScript

// Apply style to all features.
datasetLayer.style = { strokeColor: 'green', strokeWeight: 4 };
index.ts

JavaScript

// Apply style to all features.
datasetLayer.style = { strokeColor: 'green', strokeWeight: 4 };
index.js

地圖項目樣式函式

您可以使用地圖項目樣式函式，定義樣式資料集地圖項目的邏輯。如要設定地圖項目的樣式，請將 style 屬性設為 google.maps.FeatureStyleFunction。您可以運用樣式函式定義邏輯，設定地圖項目圖層上個別地圖項目的樣式。如果設為 featureLayer.style，則系統會在受影響的地圖項目圖層中，對每個地圖項目執行樣式函式。系統會在您設定樣式屬性時套用該函式，如要更新，則必須再次設定樣式屬性。下例是簡單的地圖項目樣式函式：

TypeScript

const styleDefault = {
    strokeColor: 'green',
    strokeWeight: 2.0,
    strokeOpacity: 1.0,
    fillColor: 'green',
    fillOpacity: 0.3,
};

const styleClicked = {
    ...styleDefault,
    strokeColor: 'blue',
    fillColor: 'blue',
    fillOpacity: 0.5,
};

const styleMouseMove = {
    ...styleDefault,
    strokeWeight: 4.0,
};

function applyStyle(/* FeatureStyleFunctionOptions */ params) {
    const datasetFeature = params.feature;

    // Note, 'globalid' is an attribute in this dataset.
    if (
        lastClickedFeatureIds.includes(
            datasetFeature.datasetAttributes['globalid']
        )
    ) {
        return styleClicked;
    }

    if (
        lastInteractedFeatureIds.includes(
            datasetFeature.datasetAttributes['globalid']
        )
    ) {
        return styleMouseMove;
    }
    return styleDefault;
}
index.ts

JavaScript

const styleDefault = {
    strokeColor: 'green',
    strokeWeight: 2.0,
    strokeOpacity: 1.0,
    fillColor: 'green',
    fillOpacity: 0.3,
};
const styleClicked = {
    ...styleDefault,
    strokeColor: 'blue',
    fillColor: 'blue',
    fillOpacity: 0.5,
};
const styleMouseMove = {
    ...styleDefault,
    strokeWeight: 4.0,
};
function applyStyle(/* FeatureStyleFunctionOptions */ params) {
    const datasetFeature = params.feature;
    // Note, 'globalid' is an attribute in this dataset.
    if (lastClickedFeatureIds.includes(datasetFeature.datasetAttributes['globalid'])) {
        return styleClicked;
    }
    if (lastInteractedFeatureIds.includes(datasetFeature.datasetAttributes['globalid'])) {
        return styleMouseMove;
    }
    return styleDefault;
}
index.js

如果地圖項目已套用樣式函式，該函式會一律傳回一致的結果。舉例來說，如果您想要對一組地圖項目隨機上色，該部分就不應套用地圖項目樣式函式，以免發生意外的結果。這個函式會套用至圖層中的每個地圖項目，因此請務必做好最佳化調整。為避免影響算繪時間，如果不再使用圖層，請將樣式設為 null。

點資料樣式範例

本例說明如何設定點幾何圖形的資料地圖項目樣式。

關於資料集

本例使用的資料集是紐約市中央公園 2018 年松鼠調查的結果。在以下摘錄自 CSV 資料檔案的內容中，可看出 x 和 y 資料欄用於表示地理位置；雖然包含 LatLng 資料欄，但在本例中並未使用，因為地理位置必須以兩個資料欄來表示。松鼠普查資料集含有多種不同的資料點，與觀察到的松鼠毛色和行為有關 (必須水平捲動才能查看完整內容)。

X Y UniqueSquirrelID Hectare Shift Date Hectare SquirrelNumber Age PrimaryFurColor HighlightFurColor CombinationofPrimaryandHighlightColor Colornotes Location AboveGroundSighter Measurement SpecificLocation Running Chasing Climbing Eating Foraging Other Activities Kuks Quaas Moans Tailflags Tailtwitches Approaches Indifferent Runsfrom OtherInteractions LatLng
-73.9561344937861 40.7940823884086 37F-PM-1014-03 37F PM 10142018 3 + false false false false false false false false false false false false false POINT (-73.9561344937861 40.7940823884086)
-73.9688574691102 40.7837825208444 21B-AM-1019-04 21B AM 10192018 4 + false false false false false false false false false false false false false POINT (-73.9688574691102 40.7837825208444)
-73.9742811484852 40.775533619083 11B-PM-1014-08 11B PM 10142018 8 Gray Gray+ Above Ground 10 false true false false false false false false false false false false false POINT (-73.97428114848522 40.775533619083)
-73.9596413903948 40.7903128889029 32E-PM-1017-14 32E PM 10172018 14 Adult Gray Gray+ 未選取任何「主要」項目。「灰色」獲選為「重要」項目。Made executive adjustments. false false false true true false false false false false false false true POINT (-73.9596413903948 40.7903128889029)
-73.9702676472613 40.7762126854894 13E-AM-1017-05 13E AM 10172018 5 Adult Gray Cinnamon Gray+Cinnamon Above Ground on tree stump false false false false true false false false false false false false false POINT (-73.9702676472613 40.7762126854894)
-73.9683613516225 40.7725908847499 11H-AM-1010-03 11H AM 10102018 3 Adult Cinnamon White Cinnamon+White false false false false true false false false false true false true false POINT (-73.9683613516225 40.7725908847499)
-73.9541201789795 40.7931811701082 36H-AM-1010-02 36H AM 10102018 2 Adult Gray Gray+ just outside hectare Ground Plane FALSE false false false false true false false false false false false false false POINT (-73.9541201789795 40.7931811701082)

設定點資料地圖項目的樣式

本例中的程式碼採取簡單的做法，根據 CombinationofPrimaryandHighlightColor 屬性設定每個點的填滿顏色和筆劃顏色樣式，並結合每隻松鼠的主要和次要毛色。

TypeScript

function setStyle(/* FeatureStyleFunctionOptions */ params) {
    // Get the dataset feature, so we can work with all of its attributes.
    const datasetFeature = params.feature;
    // Get all of the needed dataset attributes.
    const furColors = datasetFeature.datasetAttributes['CombinationofPrimaryandHighlightColor'];

    // Apply styles. Fill is primary fur color, stroke is secondary fur color.
    switch (furColors) {
        case 'Black+':
            return /* FeatureStyleOptions */ { fillColor: 'black', pointRadius: 8 };
            break;
        case 'Cinnamon+':
            return /* FeatureStyleOptions */ { fillColor: '#8b0000', pointRadius: 8 };
            break;
        case 'Cinnamon+Gray':
            return /* FeatureStyleOptions */ { fillColor: '#8b0000', strokeColor: 'gray', pointRadius: 6 };
            break;
        case 'Cinnamon+White':
            return /* FeatureStyleOptions */ { fillColor: '#8b0000', strokeColor: 'white', pointRadius: 6 };
            break;
        case 'Gray+':
            return /* FeatureStyleOptions */ { fillColor: 'gray', pointRadius: 8 };
            break;
        case 'Gray+Cinnamon':
            return /* FeatureStyleOptions */ { fillColor: 'gray', strokeColor: '#8b0000', pointRadius: 6 };
            break;
        case 'Gray+Cinnamon, White':
            return /* FeatureStyleOptions */ { fillColor: 'silver', strokeColor: '#8b0000', pointRadius: 6 };
            break;
        case 'Gray+White':
            return /* FeatureStyleOptions */ { fillColor: 'gray', strokeColor: 'white', pointRadius: 6 };
            break;
        default: // Color not defined.
            return /* FeatureStyleOptions */ { fillColor: 'yellow', pointRadius: 8 };
            break; 
    }
}
index.ts

JavaScript

function setStyle(/* FeatureStyleFunctionOptions */ params) {
    // Get the dataset feature, so we can work with all of its attributes.
    const datasetFeature = params.feature;
    // Get all of the needed dataset attributes.
    const furColors = datasetFeature.datasetAttributes['CombinationofPrimaryandHighlightColor'];
    // Apply styles. Fill is primary fur color, stroke is secondary fur color.
    switch (furColors) {
        case 'Black+':
            return /* FeatureStyleOptions */ { fillColor: 'black', pointRadius: 8 };
            break;
        case 'Cinnamon+':
            return /* FeatureStyleOptions */ { fillColor: '#8b0000', pointRadius: 8 };
            break;
        case 'Cinnamon+Gray':
            return /* FeatureStyleOptions */ { fillColor: '#8b0000', strokeColor: 'gray', pointRadius: 6 };
            break;
        case 'Cinnamon+White':
            return /* FeatureStyleOptions */ { fillColor: '#8b0000', strokeColor: 'white', pointRadius: 6 };
            break;
        case 'Gray+':
            return /* FeatureStyleOptions */ { fillColor: 'gray', pointRadius: 8 };
            break;
        case 'Gray+Cinnamon':
            return /* FeatureStyleOptions */ { fillColor: 'gray', strokeColor: '#8b0000', pointRadius: 6 };
            break;
        case 'Gray+Cinnamon, White':
            return /* FeatureStyleOptions */ { fillColor: 'silver', strokeColor: '#8b0000', pointRadius: 6 };
            break;
        case 'Gray+White':
            return /* FeatureStyleOptions */ { fillColor: 'gray', strokeColor: 'white', pointRadius: 6 };
            break;
        default: // Color not defined.
            return /* FeatureStyleOptions */ { fillColor: 'yellow', pointRadius: 8 };
            break;
    }
}
index.js

完整程式碼範例

查看完整原始碼範例

TypeScript

const mapElement = document.querySelector('gmp-map') as google.maps.MapElement;
let innerMap;
function setStyle(/* FeatureStyleFunctionOptions */ params) {
    // Get the dataset feature, so we can work with all of its attributes.
    const datasetFeature = params.feature;
    // Get all of the needed dataset attributes.
    const furColors = datasetFeature.datasetAttributes['CombinationofPrimaryandHighlightColor'];

    // Apply styles. Fill is primary fur color, stroke is secondary fur color.
    switch (furColors) {
        case 'Black+':
            return /* FeatureStyleOptions */ { fillColor: 'black', pointRadius: 8 };
            break;
        case 'Cinnamon+':
            return /* FeatureStyleOptions */ { fillColor: '#8b0000', pointRadius: 8 };
            break;
        case 'Cinnamon+Gray':
            return /* FeatureStyleOptions */ { fillColor: '#8b0000', strokeColor: 'gray', pointRadius: 6 };
            break;
        case 'Cinnamon+White':
            return /* FeatureStyleOptions */ { fillColor: '#8b0000', strokeColor: 'white', pointRadius: 6 };
            break;
        case 'Gray+':
            return /* FeatureStyleOptions */ { fillColor: 'gray', pointRadius: 8 };
            break;
        case 'Gray+Cinnamon':
            return /* FeatureStyleOptions */ { fillColor: 'gray', strokeColor: '#8b0000', pointRadius: 6 };
            break;
        case 'Gray+Cinnamon, White':
            return /* FeatureStyleOptions */ { fillColor: 'silver', strokeColor: '#8b0000', pointRadius: 6 };
            break;
        case 'Gray+White':
            return /* FeatureStyleOptions */ { fillColor: 'gray', strokeColor: 'white', pointRadius: 6 };
            break;
        default: // Color not defined.
            return /* FeatureStyleOptions */ { fillColor: 'yellow', pointRadius: 8 };
            break; 
    }
}

async function initMap() {
    // Request needed libraries.
    await google.maps.importLibrary('maps') as google.maps.MapsLibrary;

    // Get the inner map.
    innerMap = mapElement.innerMap;

    await google.maps.event.addListenerOnce(innerMap, 'idle', () => {
        // Add the data legend.
        makeLegend(innerMap);
    });

    // Dataset ID for squirrel dataset.
    const datasetId = 'a99635b0-5e73-4b2a-8ae3-cb40f4b7f47e';
    const datasetLayer = innerMap.getDatasetFeatureLayer(datasetId);
    datasetLayer.style = setStyle;
}

// Creates a legend for the map.
async function makeLegend(innerMap) {
    let colors = {
        'black': ['black'],
        'cinnamon': ['#8b0000'],
        'cinnamon + gray': ['#8b0000','gray'],
        'cinnamon + white': ['#8b0000', 'white'],
        'gray': ['gray'],
        'gray + cinnamon': ['gray', '#8b0000'],
        'gray + cinnamon + white': ['silver', '#8b0000'],
        'gray + white': ['gray', 'white'],
        'no color data': ['yellow'],
    };

    let legend = document.getElementById('legend');
    legend!.id = 'legend';
    let title = document.createElement('div');
    title.innerText = 'Fur Colors';
    title.classList.add('title');
    legend!.appendChild(title);
    let color;
    for (color in colors) {
        let wrapper = document.createElement('div');
        wrapper.id = 'container';
        let box = document.createElement('div');
        box.style.backgroundColor = colors[color][0];
        if (colors[color][1]) {
            box.style.borderColor = colors[color][1];
        } else {
            box.style.borderColor = colors[color][0];
        }
        box.classList.add('box');
        let txt = document.createElement('div');
        txt.classList.add('legend');
        txt.innerText = color;
        wrapper.appendChild(box);
        wrapper.appendChild(txt);
        legend!.appendChild(wrapper);
    }
}

initMap();
index.ts

JavaScript

const mapElement = document.querySelector('gmp-map');
let innerMap;
function setStyle(/* FeatureStyleFunctionOptions */ params) {
    // Get the dataset feature, so we can work with all of its attributes.
    const datasetFeature = params.feature;
    // Get all of the needed dataset attributes.
    const furColors = datasetFeature.datasetAttributes['CombinationofPrimaryandHighlightColor'];
    // Apply styles. Fill is primary fur color, stroke is secondary fur color.
    switch (furColors) {
        case 'Black+':
            return /* FeatureStyleOptions */ { fillColor: 'black', pointRadius: 8 };
            break;
        case 'Cinnamon+':
            return /* FeatureStyleOptions */ { fillColor: '#8b0000', pointRadius: 8 };
            break;
        case 'Cinnamon+Gray':
            return /* FeatureStyleOptions */ { fillColor: '#8b0000', strokeColor: 'gray', pointRadius: 6 };
            break;
        case 'Cinnamon+White':
            return /* FeatureStyleOptions */ { fillColor: '#8b0000', strokeColor: 'white', pointRadius: 6 };
            break;
        case 'Gray+':
            return /* FeatureStyleOptions */ { fillColor: 'gray', pointRadius: 8 };
            break;
        case 'Gray+Cinnamon':
            return /* FeatureStyleOptions */ { fillColor: 'gray', strokeColor: '#8b0000', pointRadius: 6 };
            break;
        case 'Gray+Cinnamon, White':
            return /* FeatureStyleOptions */ { fillColor: 'silver', strokeColor: '#8b0000', pointRadius: 6 };
            break;
        case 'Gray+White':
            return /* FeatureStyleOptions */ { fillColor: 'gray', strokeColor: 'white', pointRadius: 6 };
            break;
        default: // Color not defined.
            return /* FeatureStyleOptions */ { fillColor: 'yellow', pointRadius: 8 };
            break;
    }
}
async function initMap() {
    // Request needed libraries.
    await google.maps.importLibrary('maps');
    // Get the inner map.
    innerMap = mapElement.innerMap;
    await google.maps.event.addListenerOnce(innerMap, 'idle', () => {
        // Add the data legend.
        makeLegend(innerMap);
    });
    // Dataset ID for squirrel dataset.
    const datasetId = 'a99635b0-5e73-4b2a-8ae3-cb40f4b7f47e';
    const datasetLayer = innerMap.getDatasetFeatureLayer(datasetId);
    datasetLayer.style = setStyle;
}
// Creates a legend for the map.
async function makeLegend(innerMap) {
    let colors = {
        'black': ['black'],
        'cinnamon': ['#8b0000'],
        'cinnamon + gray': ['#8b0000', 'gray'],
        'cinnamon + white': ['#8b0000', 'white'],
        'gray': ['gray'],
        'gray + cinnamon': ['gray', '#8b0000'],
        'gray + cinnamon + white': ['silver', '#8b0000'],
        'gray + white': ['gray', 'white'],
        'no color data': ['yellow'],
    };
    let legend = document.getElementById('legend');
    legend.id = 'legend';
    let title = document.createElement('div');
    title.innerText = 'Fur Colors';
    title.classList.add('title');
    legend.appendChild(title);
    let color;
    for (color in colors) {
        let wrapper = document.createElement('div');
        wrapper.id = 'container';
        let box = document.createElement('div');
        box.style.backgroundColor = colors[color][0];
        if (colors[color][1]) {
            box.style.borderColor = colors[color][1];
        }
        else {
            box.style.borderColor = colors[color][0];
        }
        box.classList.add('box');
        let txt = document.createElement('div');
        txt.classList.add('legend');
        txt.innerText = color;
        wrapper.appendChild(box);
        wrapper.appendChild(txt);
        legend.appendChild(wrapper);
    }
}
initMap();
index.js

CSS

/* 
 * Optional: Makes the sample page fill the window. 
 */
html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

#attributionLabel {
  background-color: rgba(255, 255, 255, 0.8);
  font-family: 'Roboto' ,'Arial', 'sans-serif';
  font-size: 10px;
  padding: 2px;
  margin: 2px;
}

#legend,
#dataset,
#counter {
  background-color: #e5e5e5;
  width: 15em;

  margin-left: 1em;
  border-radius: 8px;
  font-family: Roboto;
  overflow: hidden;
}

#dataset select {
  border-radius: 0;
  padding: 0.1em;
  border: 1px solid black;
  width: auto;
  margin: 0.5em 1em;
}

.title {
  padding: 0.5em 1em;
  font-weight: bold;
  font-size: 1.5em;
  margin-bottom: 0.5em;
  background-color: rgb(66, 133, 244);
  color: white;
  width: 100%;
}

.button {
  font-size: 1.2em;
  margin: 1em;
  background-color: rgb(66, 133, 244);
  color: white;
  padding: 0.5em;
  border-radius: 8px;
}

#legend #container {
  margin: 0.5em;
  display: flex;
}

#legend div .box {
  display: flex;
  width: 1em;
  height: 1em;
  border-radius: 50%;
  border: 2px solid;
}

#legend div .legend {
  display: flex;
  padding: 0.3em;
}

style.css

HTML

<html>
    <head>
        <title>Style a point data feature</title>

        <link rel="stylesheet" type="text/css" href="./style.css" />
        <script type="module" src="./index.js"></script>
        <!-- prettier-ignore -->
        <script>(g=>{var h,a,k,p="The Google Maps JavaScript API",c="google",l="importLibrary",q="__ib__",m=document,b=window;b=b[c]||(b[c]={});var d=b.maps||(b.maps={}),r=new Set,e=new URLSearchParams,u=()=>h||(h=new Promise(async(f,n)=>{await (a=m.createElement("script"));e.set("libraries",[...r]+"");for(k in g)e.set(k.replace(/[A-Z]/g,t=>"_"+t[0].toLowerCase()),g[k]);e.set("callback",c+".maps."+q);a.src=`https://maps.${c}apis.com/maps/api/js?`+e;d[q]=f;a.onerror=()=>h=n(Error(p+" could not load."));a.nonce=m.querySelector("script[nonce]")?.nonce||"";m.head.append(a)}));d[l]?console.warn(p+" only loads once. Ignoring:",g):d[l]=(f,...n)=>r.add(f)&&u().then(()=>d[l](f,...n))})
        ({key: "AIzaSyA6myHzS10YXdcazAFalmXvDkrYCp5cLc8", v: "weekly"});</script>
    </head>
    <body>
        <gmp-map
            map-id="5cd2c9ca1cf05670"
            center="40.780101, -73.967780"
            zoom="17"
            map-type-control="false"
            street-view-control="false"
            fullscreen-control="false">
            <div id="legend" slot="control-inline-start-block-start"></div>
            <div id="attributionLabel" slot="control-block-end-inline-start">
                Data source: NYC Open Data
            </div>
        </gmp-map>
    </body>
</html>
index.html

試用範例

多邊形資料樣式範例

本例說明如何設定多邊形幾何圖形資料的地圖項目樣式。

關於資料集

本例使用的資料集呈現紐約市的公園。下方顯示具有代表性的地圖項目，摘錄自資料集 GeoJSON 檔案。

{
  "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
          ]
        ]
      ]
    ]
  }
},

設定多邊形資料地圖項目的樣式

在本例中，程式碼會將特殊顏色套用至 typecategory 為「Undeveloped」(未開發) 或「Parkway」(林蔭大道) 的資料地圖項目，並將所有其他地圖項目設為綠色。

TypeScript

function setStyle(/* FeatureStyleFunctionOptions */ params) {
    const datasetFeature = params.feature;
    // 'typecategory' is an attribute in this Dataset.
    const typeCategory = datasetFeature.datasetAttributes['typecategory'];

    switch (typeCategory) {
        case 'Undeveloped': // Color undeveloped areas blue.
            return /* FeatureStyleOptions */ {
                strokeColor: 'blue',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'blue',
                fillOpacity: 0.3,
            };
            break;
        case 'Parkway': // Color historical house sites red.
            return /* FeatureStyleOptions */ {
                strokeColor: 'red',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'red',
                fillOpacity: 0.5,
            };
            break;
        default: // Color other type categories green.
            return /* FeatureStyleOptions */ {
                strokeColor: 'green',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'green',
                fillOpacity: 0.3,
            };
            break;
    }
}
index.ts

JavaScript

function setStyle(/* FeatureStyleFunctionOptions */ params) {
    const datasetFeature = params.feature;
    // 'typecategory' is an attribute in this Dataset.
    const typeCategory = datasetFeature.datasetAttributes['typecategory'];
    switch (typeCategory) {
        case 'Undeveloped': // Color undeveloped areas blue.
            return /* FeatureStyleOptions */ {
                strokeColor: 'blue',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'blue',
                fillOpacity: 0.3,
            };
            break;
        case 'Parkway': // Color historical house sites red.
            return /* FeatureStyleOptions */ {
                strokeColor: 'red',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'red',
                fillOpacity: 0.5,
            };
            break;
        default: // Color other type categories green.
            return /* FeatureStyleOptions */ {
                strokeColor: 'green',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'green',
                fillOpacity: 0.3,
            };
            break;
    }
}
index.js

完整程式碼範例

查看完整原始碼範例

TypeScript

const mapElement = document.querySelector('gmp-map') as google.maps.MapElement;
let innerMap;
function setStyle(/* FeatureStyleFunctionOptions */ params) {
    const datasetFeature = params.feature;
    // 'typecategory' is an attribute in this Dataset.
    const typeCategory = datasetFeature.datasetAttributes['typecategory'];

    switch (typeCategory) {
        case 'Undeveloped': // Color undeveloped areas blue.
            return /* FeatureStyleOptions */ {
                strokeColor: 'blue',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'blue',
                fillOpacity: 0.3,
            };
            break;
        case 'Parkway': // Color historical house sites red.
            return /* FeatureStyleOptions */ {
                strokeColor: 'red',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'red',
                fillOpacity: 0.5,
            };
            break;
        default: // Color other type categories green.
            return /* FeatureStyleOptions */ {
                strokeColor: 'green',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'green',
                fillOpacity: 0.3,
            };
            break;
    }
}

async function initMap() {
    // Request needed libraries.
    await google.maps.importLibrary("maps") as google.maps.MapsLibrary;

    // Get the inner map.
    innerMap = mapElement.innerMap;

    // Dataset ID for NYC park data.
    const datasetId = 'a75dd002-ad20-4fe6-af60-27cd2ed636b4';
    const datasetLayer = innerMap.getDatasetFeatureLayer(datasetId);
    datasetLayer.style = setStyle;
}

initMap();
index.ts

JavaScript

const mapElement = document.querySelector('gmp-map');
let innerMap;
function setStyle(/* FeatureStyleFunctionOptions */ params) {
    const datasetFeature = params.feature;
    // 'typecategory' is an attribute in this Dataset.
    const typeCategory = datasetFeature.datasetAttributes['typecategory'];
    switch (typeCategory) {
        case 'Undeveloped': // Color undeveloped areas blue.
            return /* FeatureStyleOptions */ {
                strokeColor: 'blue',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'blue',
                fillOpacity: 0.3,
            };
            break;
        case 'Parkway': // Color historical house sites red.
            return /* FeatureStyleOptions */ {
                strokeColor: 'red',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'red',
                fillOpacity: 0.5,
            };
            break;
        default: // Color other type categories green.
            return /* FeatureStyleOptions */ {
                strokeColor: 'green',
                strokeWeight: 2,
                strokeOpacity: 1,
                fillColor: 'green',
                fillOpacity: 0.3,
            };
            break;
    }
}
async function initMap() {
    // Request needed libraries.
    await google.maps.importLibrary("maps");
    // Get the inner map.
    innerMap = mapElement.innerMap;
    // Dataset ID for NYC park data.
    const datasetId = 'a75dd002-ad20-4fe6-af60-27cd2ed636b4';
    const datasetLayer = innerMap.getDatasetFeatureLayer(datasetId);
    datasetLayer.style = setStyle;
}
initMap();
index.js

CSS

/* 
 * Optional: Makes the sample page fill the window. 
 */
html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

#attribution {
 background-color: rgba(255, 255, 255, 0.7);
 font-family: "Roboto", "Arial", "sans-serif";
 font-size: 10px;
 padding: 2px;
 margin: 2px;
}

style.css

HTML

<html>
  <head>
    <title>Style a polygon data feature with more detail</title>

    <link rel="stylesheet" type="text/css" href="./style.css" />
    <script type="module" src="./index.js"></script>
    <!-- prettier-ignore -->
    <script>(g=>{var h,a,k,p="The Google Maps JavaScript API",c="google",l="importLibrary",q="__ib__",m=document,b=window;b=b[c]||(b[c]={});var d=b.maps||(b.maps={}),r=new Set,e=new URLSearchParams,u=()=>h||(h=new Promise(async(f,n)=>{await (a=m.createElement("script"));e.set("libraries",[...r]+"");for(k in g)e.set(k.replace(/[A-Z]/g,t=>"_"+t[0].toLowerCase()),g[k]);e.set("callback",c+".maps."+q);a.src=`https://maps.${c}apis.com/maps/api/js?`+e;d[q]=f;a.onerror=()=>h=n(Error(p+" could not load."));a.nonce=m.querySelector("script[nonce]")?.nonce||"";m.head.append(a)}));d[l]?console.warn(p+" only loads once. Ignoring:",g):d[l]=(f,...n)=>r.add(f)&&u().then(()=>d[l](f,...n))})
        ({key: "AIzaSyA6myHzS10YXdcazAFalmXvDkrYCp5cLc8", v: "weekly"});</script>
  </head>
  <body>
        <gmp-map center="40.580732, -74.152826" zoom="14" map-id="5cd2c9ca1cf05670">
            <div id="attribution" slot="control-block-end-inline-start">Data source: NYC Open Data</div>
        </gmp-map>
  </body>
</html>
index.html

試用範例

折線資料樣式範例

本例說明如何設定折線幾何圖形資料的地圖項目樣式。

關於資料集

本例使用的資料集呈現西雅圖地區的橋樑。下方顯示具有代表性的地圖項目，摘錄自資料集 GeoJSON 檔案。

{
  "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
          ]
      ]
  }
},

設定折線資料地圖項目的樣式

以下程式碼片段會將相同的樣式直接套用至所有資料地圖項目。由於不需要套用邏輯，因此本例未使用地圖項目樣式函式。

TypeScript

// Apply style to all features.
datasetLayer.style = { strokeColor: 'green', strokeWeight: 4 };
index.ts

JavaScript

// Apply style to all features.
datasetLayer.style = { strokeColor: 'green', strokeWeight: 4 };
index.js

查看完整原始碼範例

TypeScript

const mapElement = document.querySelector('gmp-map') as google.maps.MapElement;
let innerMap;
async function initMap() {
    // Request needed libraries.
    (await google.maps.importLibrary('maps')) as google.maps.MapsLibrary;

    // Get the inner map.
    innerMap = mapElement.innerMap;

    // Dataset ID for Seattle Bridges
    const datasetId = '2438ee30-5366-4e84-82b7-a0d4dd1893fa';
    const datasetLayer = innerMap.getDatasetFeatureLayer(datasetId);

    // Apply style to all features.
    datasetLayer.style = { strokeColor: 'green', strokeWeight: 4 };
}

initMap();
index.ts

JavaScript

const mapElement = document.querySelector('gmp-map');
let innerMap;
async function initMap() {
    // Request needed libraries.
    (await google.maps.importLibrary('maps'));
    // Get the inner map.
    innerMap = mapElement.innerMap;
    // Dataset ID for Seattle Bridges
    const datasetId = '2438ee30-5366-4e84-82b7-a0d4dd1893fa';
    const datasetLayer = innerMap.getDatasetFeatureLayer(datasetId);
    // Apply style to all features.
    datasetLayer.style = { strokeColor: 'green', strokeWeight: 4 };
}
initMap();
index.js

CSS

/* 
 * Optional: Makes the sample page fill the window. 
 */
html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

#attribution {
 background-color: rgba(255, 255, 255, 0.7);
 font-family: "Roboto", "Arial", "sans-serif";
 font-size: 10px;
 padding: 2px;
 margin: 2px;
}

style.css

HTML

<html>
    <head>
        <title>Style a polyline data feature</title>

        <link rel="stylesheet" type="text/css" href="./style.css" />
        <script type="module" src="./index.js"></script>
        <!-- prettier-ignore -->
        <script>(g=>{var h,a,k,p="The Google Maps JavaScript API",c="google",l="importLibrary",q="__ib__",m=document,b=window;b=b[c]||(b[c]={});var d=b.maps||(b.maps={}),r=new Set,e=new URLSearchParams,u=()=>h||(h=new Promise(async(f,n)=>{await (a=m.createElement("script"));e.set("libraries",[...r]+"");for(k in g)e.set(k.replace(/[A-Z]/g,t=>"_"+t[0].toLowerCase()),g[k]);e.set("callback",c+".maps."+q);a.src=`https://maps.${c}apis.com/maps/api/js?`+e;d[q]=f;a.onerror=()=>h=n(Error(p+" could not load."));a.nonce=m.querySelector("script[nonce]")?.nonce||"";m.head.append(a)}));d[l]?console.warn(p+" only loads once. Ignoring:",g):d[l]=(f,...n)=>r.add(f)&&u().then(()=>d[l](f,...n))})
        ({key: "AIzaSyA6myHzS10YXdcazAFalmXvDkrYCp5cLc8", v: "weekly"});</script>
    </head>
    <body>
        <gmp-map
            center="47.59, -122.31"
            zoom="14"
            map-id="5cd2c9ca1cf05670"
            map-type-control="false">
            <div id="attribution" slot="control-block-end-inline-start">
                Data source: NYC Open Data
            </div>
        </gmp-map>
    </body>
</html>
index.html

試用範例