GetDpiForMonitor function (shellscalingapi.h)

Queries the dots per inch (dpi) of a display.

Syntax

HRESULT GetDpiForMonitor(
  [in]  HMONITOR         hmonitor,
  [in]  MONITOR_DPI_TYPE dpiType,
  [out] UINT             *dpiX,
  [out] UINT             *dpiY
);

Parameters

[in] hmonitor

Handle of the monitor being queried.

[in] dpiType

The type of DPI being queried. Possible values are from the MONITOR_DPI_TYPE enumeration.

[out] dpiX

The value of the DPI along the X axis. This value always refers to the horizontal edge, even when the screen is rotated.

[out] dpiY

The value of the DPI along the Y axis. This value always refers to the vertical edge, even when the screen is rotated.

Return value

This function returns one of the following values.

Remarks

This API is not DPI aware and should not be used if the calling thread is per-monitor DPI aware. For the DPI-aware version of this API, see GetDpiForWindow.

When you call GetDpiForMonitor, you will receive different DPI values depending on the DPI awareness of the calling application. DPI awareness is an application-level property usually defined in the application manifest. For more information about DPI awareness values, see PROCESS_DPI_AWARENESS. The following table indicates how the results will differ based on the PROCESS_DPI_AWARENESS value of your application.

The values of *dpiX and *dpiY are identical. You only need to record one of the values to determine the DPI and respond appropriately.

When MONITOR_DPI_TYPE is MDT_ANGULAR_DPI or MDT_RAW_DPI, the returned DPI value does not include any changes that the user made to the DPI by using the desktop scaling override slider control in Control Panel.

For more information about DPI settings in Control Panel, see the Writing DPI-Aware Desktop Applications in Windows 8.1 Preview white paper.

Requirements

See also

PROCESS_DPI_AWARENESS