您好，我这边测试了一下，不论是2D还是2.5D模式下， viewer.dataSources.removeAll() 都是没有问题的，您可以把下面的代码粘贴到官网示例里面去运行
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=Edge,chrome=1">
<meta http-equiv="pragma" content="no-cache">
<meta name="viewport"
content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no">
<title>平面、三维场景切换</title>
<link href="../../Build/Cesium/Widgets/widgets.css" rel="stylesheet">
<link href="./css/bootstrap.min.css" rel="stylesheet">
<link href="./css/pretty.css" rel="stylesheet">
<script src="./js/jquery.min.js"></script>
<script src="./js/bootstrap.min.js"></script>
<script src="./js/bootstrap-select.min.js"></script>
<script type="text/javascript" src="http://www.supermapol.com/earth/Build/Cesium/Cesium.js"></script>
<script src="./js/config.js"></script>
</head>
<body>
<div id="cesiumContainer"></div>
<div id='loadingbar' class="spinner">
<div class="spinner-container container1">
<div class="circle1"></div>
<div class="circle2"></div>
<div class="circle3"></div>
<div class="circle4"></div>
</div>
<div class="spinner-container container2">
<div class="circle1"></div>
<div class="circle2"></div>
<div class="circle3"></div>
<div class="circle4"></div>
</div>
<div class="spinner-container container3">
<div class="circle1"></div>
<div class="circle2"></div>
<div class="circle3"></div>
<div class="circle4"></div>
</div>
</div>
<div id="toolbar" style="position: absolute;left: 5px;top: 5px;display: none;">
<select id="imageryOptions" class="selectpicker show-tick form-control">
<!--<option disabled selected value>--选择服务类型--</option>-->
<option selected value="WGS">自定义影像&地形-平面场景</option>
<option value="MEC">倾斜数据-三维场景</option>
</select>
<button id='tt'>清除</button>
</div>
<script>
function onload(Cesium) {
//初始化viewer部件
var viewer = new Cesium.Viewer('cesiumContainer', {
terrainProvider: new Cesium.CesiumTerrainProvider({
url: URL_CONFIG.ZF_TERRAIN,
isSct: true//地形服务源自SuperMap iServer发布时需设置isSct为true
}),
sceneModePicker: true,
navigation: false,
});
var layer = viewer.imageryLayers.addImageryProvider(new Cesium.SuperMapImageryProvider({
url: URL_CONFIG.ZF_IMG
}));
viewer.scene.camera.setView({
destination: new Cesium.Cartesian3(-1226925.7054612704, 5354675.979312425, 3270577.600069679),
orientation: {
heading: 6.109613004885443,
pitch: -0.48783918611301136,
roll: 6.283185307179586
}
});
var scene = viewer.scene;
var promise = scene.addS3MTilesLayerByScp(URL_CONFIG.SCP_JINJIANG);
viewer.scene.mode = Cesium.SceneMode.SCENE2D;//平面场景
//加载线数据
var roadLine1 = Cesium.GeoJsonDataSource.load('./data/json/lineback_1.json');
roadLine1.then(function (dataSource) {
viewer.dataSources.add(dataSource);
var lines_1 = dataSource.entities.values;
for (var i = 0; i < lines_1.length; i++) {
var line = lines_1[i];
line.polyline.material = new Cesium.PolylineGlowMaterialProperty({ //设置Glow材质
glowPower: 0.005,
color: new Cesium.Color(8, 5, 0, 0.3)
});
line.polyline.width = 6;
}
}).otherwise(function (error) {
window.alert(error);
});
$('#tt').click(function(){
viewer.dataSources.removeAll();
console.log(1111111)
})
//添加下拉菜单，点击选项切换地图服务
$('#imageryOptions').change(function () {
var value = $(this).val();
if (value == 'WGS') {
viewer.scene.camera.setView({
destination: new Cesium.Cartesian3(-1226925.7054612704, 5354675.979312425, 3270577.600069679),
orientation: {
heading: 6.109613004885443,
pitch: -0.48783918611301136,
roll: 6.283185307179586
}
});
viewer.scene.mode = Cesium.SceneMode.SCENE2D;//平面场景
//平面场景
}
else if (value == 'MEC') {
Cesium.when(promise, function (layers) {
viewer.scene.mode = Cesium.SceneMode.SCENE3D;//三维场景
//设置相机位置，定位至模型
scene.camera.setView({
//将经度、纬度、高度的坐标转换为笛卡尔坐标
destination: Cesium.Cartesian3.fromDegrees(118.54909017414182, 24.80259473610606, 105.40531821331771),
orientation: {
heading: 5.154573786584606,
pitch: -0.14229615865957967,
roll: 3.2294167340296553e-12
}
});
});
}
});
$('#toolbar').show();
$('#loadingbar').remove();
}
if (typeof Cesium !== 'undefined') {
window.startupCalled = true;
onload(Cesium);
}
</script>
</body>
</html>
