ILocation::RequestPermissions method (locationapi.h)

Article
10/13/2021

[The Win32 Location API is available for use in the operating systems specified in the Requirements section. It may be altered or unavailable in subsequent versions. Instead, use the Windows.Devices.Geolocation API. ]

Opens a system dialog box to request user permission to enable location devices.

Syntax

HRESULT RequestPermissions(
  [in] HWND  hParent,
  [in] IID   *pReportTypes,
  [in] ULONG count,
       BOOL  fModal
);

Parameters

[in] hParent

HWND for the parent window. This parameter is optional. In Windows 8 the dialog is always modal if hParent is provided, and not modal if hParent is NULL.

[in] pReportTypes

Pointer to an IID array. This array must contain interface IDs for all report types for which you are requesting permission. The interface IDs of the valid report types are IID_ILatLongReport and IID_ICivicAddressReport. The count of IDs must match the value specified through the count parameter.

[in] count

The count of interface IDs contained in pReportTypes.

fModal

This parameter is not used.

Return value

This method can return one of these values.

The following table describes return codes when the call is synchronous.

Return code	Description
S_OK	The user enabled location services. The method succeeded.
HRESULT_FROM_WIN32(ERROR_ACCESS_DENIED)	The location platform is disabled. An administrator turned the location platform off.
HRESULT_FROM_WIN32(ERROR_CANCELLED)	The user did not enable access to location services or canceled the dialog box.

The following table describes return codes when the call is asynchronous.

Return code	Description
S_OK	The user enabled access to location services. The method succeeded.
E_INVALIDARG	An argument is not valid.
HRESULT_FROM_WIN32(ERROR_ACCESS_DENIED)	The location platform is disabled. An administrator turned the location platform off. The dialog box was not shown.

Remarks

If the user chooses not to enable location services, Windows will not show the permissions dialog box again.

Note Repeated asynchronous calls to RequestPermissions will display multiple instances of the Enable location services dialog box and can potentially flood the screen with dialog boxes, resulting in a poor user experience. If you think that other location sensors might be installed after your first call to RequestPermissions, requiring another call to RequestPermissions, you should either call RequestPermissions synchronously or wait until all location sensors are installed to make an asynchronous call.

Note Making a synchronous call from the user interface (UI) thread of a Windows application can block the UI thread and make the application less responsive. To prevent this, do not make a synchronous call to RequestPermissions from the UI thread.

Note If an application running in protected mode, such as a Browser Helper Object (BHO) for Internet Explorer, calls RequestPermissions, and the user chooses not to enable location using the dialog box, the location provider will not be enabled, but Windows will display the dialog box again if RequestPermissions is called again by the same user.

Examples

The following example demonstrates how to call RequestPermissions to request permission for latitude/longitude reports.

             // Array of report types of interest. Other ones include IID_ICivicAddressReport
            IID REPORT_TYPES[] = { IID_ILatLongReport };

            // Request permissions for this user account to receive location data for all the
            // types defined in REPORT_TYPES (which is currently just one report type)
            // The last parameter is not used.
            if (FAILED(spLocation->RequestPermissions(
                  NULL, 
                  REPORT_TYPES, 
                  ARRAYSIZE(REPORT_TYPES), 
                  TRUE))) 
            {
                wprintf(L"Warning: Unable to request permissions.\n");
            }

Requirements

Requirement	Value
Minimum supported client	Windows 7 [desktop apps only],Windows 7
Minimum supported server	None supported
Target Platform	Windows
Header	locationapi.h
DLL	LocationAPI.dll

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