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Vector Map - Dynamic Viewport

This demo illustrates how to change the map's viewport. Use the drop-down menu under the map to choose a continent and change the visible area so that the chosen continent is displayed optimally.

To implement this functionality, call the viewport(viewportCoordinates) method every time the drop-down box value changes. You can also implement the onCenterChanged and onZoomFactorChanged functions to display the map center's coordinates and the current zoom factor in text boxes under the map.

Backend API
@model IEnumerable<DevExtreme.NETCore.Demos.Models.ViewportCoordinate> @(Html.DevExtreme().VectorMap() .ID("vector-map") .Layers(l => l.Add().DataSource(new JS("DevExpress.viz.map.sources.world"))) .Bounds(new double[] { -180, 85, 180, -60 }) .OnZoomFactorChanged("vectorMap_onZoomFactorChanged") .OnCenterChanged("vectorMap_onCenterChanged") ) <div class="options"> <div class="caption">Options</div> <div class="wrapper-option"> <div class="column"> <div class="option"> <span>Continent</span> @(Html.DevExtreme().SelectBox() .ID("choose-continent") .DataSource(Model) .Width(210) .InputAttr("aria-label", "Continent") .DisplayExpr("Continent") .ValueExpr("Coordinates") .Value(Model.First().Coordinates) .OnValueChanged("selectBox_onValueChanged") ) </div> <div class="option"> <span>Zoom factor</span> @(Html.DevExtreme().TextBox() .ID("zoom-factor") .Width(210) .InputAttr("aria-label", "Zoom") .ReadOnly(true) .Value("1.00") ) </div> <div class="option"> <span>Center</span> @(Html.DevExtreme().TextBox() .ID("center") .Width(210) .ReadOnly(true) .InputAttr("aria-label", "Center") .Value("0.000, 46.036") ) </div> </div> <div class="column"> <div class="option"> <span>Pan control</span> @(Html.DevExtreme().Switch() .OnValueChanged("switch_panVisible") .Value(true) ) </div> <div class="option"> <span>Zoom bar</span> @(Html.DevExtreme().Switch() .OnValueChanged("switch_zoomVisible") .Value(true) ) </div> </div> </div> </div> <script> function vectorMap_onZoomFactorChanged(e) { $("#zoom-factor").dxTextBox("instance").option("value", e.zoomFactor.toFixed(2)); } function vectorMap_onCenterChanged(e) { $("#center").dxTextBox("instance").option("value", e.center[0].toFixed(3) + ", " + e.center[1].toFixed(3)); } function selectBox_onValueChanged(data) { $("#vector-map").dxVectorMap("instance").viewport(data.value); } function switch_panVisible(data) { $("#vector-map").dxVectorMap("instance").option('controlBar.panVisible', data.value); } function switch_zoomVisible(data) { $("#vector-map").dxVectorMap("instance").option('controlBar.zoomVisible', data.value); } </script>
using Microsoft.AspNetCore.Mvc; using DevExtreme.NETCore.Demos.Models.SampleData; namespace DevExtreme.NETCore.Demos.Controllers { public class VectorMapController : Controller { public ActionResult DynamicViewport() { return View(SampleData.ViewportCoordinateData); } } }
namespace DevExtreme.NETCore.Demos.Models { public class ViewportCoordinate { public string Continent { get; set; } public object Coordinates { get; set; } } }
using System.Collections.Generic; namespace DevExtreme.NETCore.Demos.Models.SampleData { public partial class SampleData { public static readonly IEnumerable<ViewportCoordinate> ViewportCoordinateData = new[] { new ViewportCoordinate() { Continent = "all", Coordinates = "null" }, new ViewportCoordinate() { Continent = "NorthAmerica", Coordinates = new[] { -180, 84.52, -22.11, -1.57 } }, new ViewportCoordinate() { Continent = "SouthAmerica", Coordinates = new[] { -112.47, 14.26, -27.52, -57.44 } }, new ViewportCoordinate() { Continent = "Africa", Coordinates = new[] { -29.34, 39.09, 55.60, -39.00 } }, new ViewportCoordinate() { Continent = "Europe", Coordinates = new[] { -2.35, 70.91, 61.35, 35.84 } }, new ViewportCoordinate() { Continent = "Asia", Coordinates = new[] { 27.62, 83.11, 180, -19.36 } }, new ViewportCoordinate() { Continent = "Australia", Coordinates = new[] { 104.87, -6.61, 149.98, -45.87 } } }; } }
#vector-map { height: 420px; } .options { padding: 20px; background-color: rgba(191, 191, 191, 0.15); margin-top: 20px; } .wrapper-option { display: flex; gap: 24px; padding-top: 16px; } .column { display: flex; gap: 10px; flex-direction: column; } .option { display: flex; align-items: center; min-height: 34px; } .caption { font-size: 18px; font-weight: 500; } .option > span { width: 140px; }

To show or hide the control bar, enable or disable the panVisible and zoomVisible properties. You can toggle switches under the map to see how these settings affect the control bar.