Places List (QML)

运行范例

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Places List example demonstrates how to search for a list of places in a certain area and displays the result using a ListView . In this particular case, a search for places associated with the term pizza 的履行。

Performing a Place Search

To write a QML application that will show places in a list, we start by making the following import declarations.

import QtQuick 2.0
import QtPositioning 5.5
import QtLocation 5.6

Instantiate a Plugin instance. The Plugin is effectively the backend from where places are sourced from. Depending on the type of the plugin, some mandatory parameters may be need to be filled in. The most likely type of PluginParameter are some form of service access token which are documented in the service plugin. As an example see the HERE Plugin documentation. In this snippet the osm plugin is used which does not require any further parameter:

Plugin {
    id: myPlugin
    name: "osm"
    //specify plugin parameters as necessary
    //PluginParameter {...}
    //PluginParameter {...}
    //...
}

Next we instantiate a PlaceSearchModel which we can use to specify search parameters and perform a places search operation. For illustrative purposes, update() is invoked once construction of the model is complete. Typically update() would be invoked in response to a user action such as a button click.

PlaceSearchModel {
    id: searchModel
    plugin: myPlugin
    searchTerm: "pizza"
    searchArea: QtPositioning.circle(startCoordinate);
    Component.onCompleted: update()
}

Finally we instantiate a ListView to show the search results found by the model. An inline delegate has been used and we have assumed that every search result is of type PlaceSearchesult . Consequently it is assumed that we always have access to the place role , other search result types may not have a place role .

ListView {
    anchors.fill: parent
    model: searchModel
    delegate: Component {
        Row {
            spacing: 5
            Marker { height: parent.height }
            Column {
                Text { text: title; font.bold: true }
                Text { text: place.location.address.text }
            }
        }
    }
}

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