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'];
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"];
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, };
JavaScript
// Apply style to all features.
datasetLayer.style = { strokeColor: "green", strokeWeight: 4 };
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.
//@ts-ignore
if (lastClickedFeatureIds.includes(datasetFeature.datasetAttributes['globalid'])) {
return styleClicked;
}
//@ts-ignore
if (lastInteractedFeatureIds.includes(datasetFeature.datasetAttributes['globalid'])) {
return styleMouseMove;
}
return styleDefault;
}
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.
//@ts-ignore
if (
lastClickedFeatureIds.includes(datasetFeature.datasetAttributes["globalid"])
) {
return styleClicked;
}
//@ts-ignore
if (
lastInteractedFeatureIds.includes(
datasetFeature.datasetAttributes["globalid"],
)
) {
return styleMouseMove;
}
return styleDefault;
}
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;
}
}
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;
}
}
完整程式碼範例
查看完整原始碼範例
TypeScript
let map;
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.
const { Map } = await google.maps.importLibrary('maps') as google.maps.MapsLibrary;
const position = {lat: 40.780101, lng: -73.967780};
const map = new Map(document.getElementById('map') as HTMLElement, {
zoom: 17,
center: position,
mapId: 'b98e588c46685dd7',
mapTypeControl: false,
streetViewControl: false,
fullscreenControl: false,
});
// Add the data legend.
makeLegend(map);
// Dataset ID for squirrel dataset.
const datasetId = '02fa1552-37dd-4a95-844f-f99e1c22541f';
//@ts-ignore
const datasetLayer = map.getDatasetFeatureLayer(datasetId);
//@ts-ignore
datasetLayer.style = setStyle;
// Create an attribution DIV and add the attribution to the map.
const attributionDiv = document.createElement('div');
const attributionControl = createAttribution(map);
attributionDiv.appendChild(attributionControl);
map.controls[google.maps.ControlPosition.BOTTOM_LEFT].push(attributionDiv);
}
// Create a custom control to hold attribution text.
function createAttribution(map) {
const attributionLabel = document.createElement('div');
// Define CSS styles.
attributionLabel.style.backgroundColor = '#fff';
attributionLabel.style.opacity = '0.7';
attributionLabel.style.fontFamily = 'Roboto,Arial,sans-serif';
attributionLabel.style.fontSize = '10px';
attributionLabel.style.padding = '2px';
attributionLabel.style.margin = '2px';
attributionLabel.textContent = 'Data source: NYC Open Data';
return attributionLabel;
}
function makeLegend(map) {
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.createElement('div');
legend.id = 'legend';
let title = document.createElement('div');
title.innerText = 'Fur Colors';
title.classList.add('title');
legend.appendChild(title);
let k;
for (k in colors) {
let wrapper = document.createElement('div');
wrapper.id = 'container';
let box = document.createElement('div');
box.style.backgroundColor = colors[k][0];
if (colors[k][1]) {
box.style.borderColor = colors[k][1];
} else {
box.style.borderColor = colors[k][0];
}
box.classList.add('box');
let txt = document.createElement('div');
txt.classList.add('legend');
txt.innerText = k;
wrapper.appendChild(box);
wrapper.appendChild(txt);
legend.appendChild(wrapper);
}
map.controls[google.maps.ControlPosition.LEFT_TOP].push(legend);
}
initMap();
JavaScript
let map;
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.
const { Map } = await google.maps.importLibrary("maps");
const position = { lat: 40.780101, lng: -73.96778 };
const map = new Map(document.getElementById("map"), {
zoom: 17,
center: position,
mapId: "b98e588c46685dd7",
mapTypeControl: false,
streetViewControl: false,
fullscreenControl: false,
});
// Add the data legend.
makeLegend(map);
// Dataset ID for squirrel dataset.
const datasetId = "02fa1552-37dd-4a95-844f-f99e1c22541f";
//@ts-ignore
const datasetLayer = map.getDatasetFeatureLayer(datasetId);
//@ts-ignore
datasetLayer.style = setStyle;
// Create an attribution DIV and add the attribution to the map.
const attributionDiv = document.createElement("div");
const attributionControl = createAttribution(map);
attributionDiv.appendChild(attributionControl);
map.controls[google.maps.ControlPosition.BOTTOM_LEFT].push(attributionDiv);
}
// Create a custom control to hold attribution text.
function createAttribution(map) {
const attributionLabel = document.createElement("div");
// Define CSS styles.
attributionLabel.style.backgroundColor = "#fff";
attributionLabel.style.opacity = "0.7";
attributionLabel.style.fontFamily = "Roboto,Arial,sans-serif";
attributionLabel.style.fontSize = "10px";
attributionLabel.style.padding = "2px";
attributionLabel.style.margin = "2px";
attributionLabel.textContent = "Data source: NYC Open Data";
return attributionLabel;
}
function makeLegend(map) {
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.createElement("div");
legend.id = "legend";
let title = document.createElement("div");
title.innerText = "Fur Colors";
title.classList.add("title");
legend.appendChild(title);
let k;
for (k in colors) {
let wrapper = document.createElement("div");
wrapper.id = "container";
let box = document.createElement("div");
box.style.backgroundColor = colors[k][0];
if (colors[k][1]) {
box.style.borderColor = colors[k][1];
} else {
box.style.borderColor = colors[k][0];
}
box.classList.add("box");
let txt = document.createElement("div");
txt.classList.add("legend");
txt.innerText = k;
wrapper.appendChild(box);
wrapper.appendChild(txt);
legend.appendChild(wrapper);
}
map.controls[google.maps.ControlPosition.LEFT_TOP].push(legend);
}
initMap();
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;
}
}
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;
}
}
完整程式碼範例
查看完整原始碼範例
TypeScript
let map;
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.
const { Map } = await google.maps.importLibrary("maps") as google.maps.MapsLibrary;
const position = {lat: 40.580732, lng: -74.152826};
const map = new Map(document.getElementById('map') as HTMLElement, {
zoom: 14,
center: position,
mapId: 'b98e588c46685dd7',
mapTypeControl: false,
});
// Dataset ID for NYC park data.
const datasetId = '6fe13aa9-b900-45e7-b636-3236672c3f4f';
//@ts-ignore
const datasetLayer = map.getDatasetFeatureLayer(datasetId);
datasetLayer.style = setStyle;
// Create an attribution DIV and add the attribution to the map.
const attributionDiv = document.createElement('div');
const attributionControl = createAttribution(map);
attributionDiv.appendChild(attributionControl);
map.controls[google.maps.ControlPosition.LEFT_BOTTOM].push(attributionDiv);
}
function createAttribution(map) {
const attributionLabel = document.createElement('div');
// Define CSS styles.
attributionLabel.style.backgroundColor = '#fff';
attributionLabel.style.opacity = '0.7';
attributionLabel.style.fontFamily = 'Roboto,Arial,sans-serif';
attributionLabel.style.fontSize = '10px';
attributionLabel.style.padding = '2px';
attributionLabel.style.margin = '2px';
attributionLabel.textContent = 'Data source: NYC Open Data';
return attributionLabel;
}
initMap();
JavaScript
let map;
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.
const { Map } = await google.maps.importLibrary("maps");
const position = { lat: 40.580732, lng: -74.152826 };
const map = new Map(document.getElementById("map"), {
zoom: 14,
center: position,
mapId: "b98e588c46685dd7",
mapTypeControl: false,
});
// Dataset ID for NYC park data.
const datasetId = "6fe13aa9-b900-45e7-b636-3236672c3f4f";
//@ts-ignore
const datasetLayer = map.getDatasetFeatureLayer(datasetId);
datasetLayer.style = setStyle;
// Create an attribution DIV and add the attribution to the map.
const attributionDiv = document.createElement("div");
const attributionControl = createAttribution(map);
attributionDiv.appendChild(attributionControl);
map.controls[google.maps.ControlPosition.LEFT_BOTTOM].push(attributionDiv);
}
function createAttribution(map) {
const attributionLabel = document.createElement("div");
// Define CSS styles.
attributionLabel.style.backgroundColor = "#fff";
attributionLabel.style.opacity = "0.7";
attributionLabel.style.fontFamily = "Roboto,Arial,sans-serif";
attributionLabel.style.fontSize = "10px";
attributionLabel.style.padding = "2px";
attributionLabel.style.margin = "2px";
attributionLabel.textContent = "Data source: NYC Open Data";
return attributionLabel;
}
initMap();
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, };
JavaScript
// Apply style to all features.
datasetLayer.style = { strokeColor: "green", strokeWeight: 4 };
查看完整原始碼範例
TypeScript
let map;
async function initMap() {
// Request needed libraries.
const { Map } = await google.maps.importLibrary("maps") as google.maps.MapsLibrary;
const position = {lat: 47.59, lng: -122.31};
const map = new Map(document.getElementById('map') as HTMLElement, {
zoom: 14,
center: position,
mapId: 'b98e588c46685dd7',
mapTypeControl: false,
});
// Dataset ID for Seattle Bridges
const datasetId = '3d0bd5fb-3f42-47fe-b50f-81c0932cd533';
//@ts-ignore
const datasetLayer = map.getDatasetFeatureLayer(datasetId);
// Apply style to all features.
datasetLayer.style = { strokeColor: 'green', strokeWeight: 4, };
// Create an attribution DIV and add the attribution to the map.
const attributionDiv = document.createElement('div');
const attributionControl = createAttribution(map);
attributionDiv.appendChild(attributionControl);
map.controls[google.maps.ControlPosition.LEFT_BOTTOM].push(attributionDiv);
}
// Create a custom control to hold attribution text.
function createAttribution(map) {
const attributionLabel = document.createElement('div');
// Define CSS styles.
attributionLabel.style.backgroundColor = '#fff';
attributionLabel.style.opacity = '0.7';
attributionLabel.style.fontFamily = 'Roboto,Arial,sans-serif';
attributionLabel.style.fontSize = '10px';
attributionLabel.style.padding = '2px';
attributionLabel.style.margin = '2px';
attributionLabel.textContent = 'Data source: Seattle GeoData';
return attributionLabel;
}
initMap();
JavaScript
let map;
async function initMap() {
// Request needed libraries.
const { Map } = await google.maps.importLibrary("maps");
const position = { lat: 47.59, lng: -122.31 };
const map = new Map(document.getElementById("map"), {
zoom: 14,
center: position,
mapId: "b98e588c46685dd7",
mapTypeControl: false,
});
// Dataset ID for Seattle Bridges
const datasetId = "3d0bd5fb-3f42-47fe-b50f-81c0932cd533";
//@ts-ignore
const datasetLayer = map.getDatasetFeatureLayer(datasetId);
// Apply style to all features.
datasetLayer.style = { strokeColor: "green", strokeWeight: 4 };
// Create an attribution DIV and add the attribution to the map.
const attributionDiv = document.createElement("div");
const attributionControl = createAttribution(map);
attributionDiv.appendChild(attributionControl);
map.controls[google.maps.ControlPosition.LEFT_BOTTOM].push(attributionDiv);
}
// Create a custom control to hold attribution text.
function createAttribution(map) {
const attributionLabel = document.createElement("div");
// Define CSS styles.
attributionLabel.style.backgroundColor = "#fff";
attributionLabel.style.opacity = "0.7";
attributionLabel.style.fontFamily = "Roboto,Arial,sans-serif";
attributionLabel.style.fontSize = "10px";
attributionLabel.style.padding = "2px";
attributionLabel.style.margin = "2px";
attributionLabel.textContent = "Data source: Seattle GeoData";
return attributionLabel;
}
initMap();