Android API中所有提供Location的Provider

    /**
     * Name of the network location provider.
     * <p>This provider determines location based on
     * availability of cell tower and WiFi access points. Results are retrieved
     * by means of a network lookup.
     */
    public static final String NETWORK_PROVIDER = "network";

    /**
     * Name of the GPS location provider.
     *
     * <p>This provider determines location using
     * satellites. Depending on conditions, this provider may take a while to return
     * a location fix. Requires the permission
     * {@link android.Manifest.permission#ACCESS_FINE_LOCATION}.
     *
     * <p> The extras Bundle for the GPS location provider can contain the
     * following key/value pairs:
     * <ul>
     * <li> satellites - the number of satellites used to derive the fix
     * </ul>
     */
    public static final String GPS_PROVIDER = "gps";

    /**
     * A special location provider for receiving locations without actually initiating
     * a location fix.
     *
     * <p>This provider can be used to passively receive location updates
     * when other applications or services request them without actually requesting
     * the locations yourself.  This provider will return locations generated by other
     * providers.  You can query the {@link Location#getProvider()} method to determine
     * the origin of the location update. Requires the permission
     * {@link android.Manifest.permission#ACCESS_FINE_LOCATION}, although if the GPS is
     * not enabled this provider might only return coarse fixes.
     */
    public static final String PASSIVE_PROVIDER = "passive";

    /**
     * Name of the Fused location provider.
     *
     * <p>This provider combines inputs for all possible location sources
     * to provide the best possible Location fix. It is implicitly
     * used for all API's that involve the {@link LocationRequest}
     * object.
     *
     * @hide
     */
    public static final String FUSED_PROVIDER = "fused";