This sample shows how to add an instance of MapImageLayer to a Map in a MapView and update thedefinitionExpression of a sublayer.
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// This layer has four sublayers. You can define the definitionExpression in each sublayer.
const layer = new MapImageLayer({
url: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/USA/MapServer",
sublayers: [
{
id: 3,
visible: false
},
{
id: 2,
visible: true
},
{
id: 1,
visible: true
},
{
id: 0,
visible: true,
definitionExpression: "pop2000 > 100000"
}
]
});
...
/*****************************************************************
* Listen for events on when the slider values have changed.
* When the slider value changes, apply the new value to the
* MapImageLayer definitionExpression.
*****************************************************************/
layer.when(() => {
const cities = layer.findSublayerById(0);
populationSlider.on("thumb-drag", populationValueChanged);
const populationValueChanged = (event) => {
selectedPopulation = event.value;
document.getElementById("population-display").innerHTML = parseInt(selectedPopulation).toLocaleString()
// update the layers after the user stops the slider to avoid continues requests
if (event.state === 'stop')
{
cities.definitionExpression = "pop2000 > " + selectedPopulation;
}
}
});