SetProcessDpiAwareness function (shellscalingapi.h)

Sets the process-default DPI awareness level. This is equivalent to calling SetProcessDpiAwarenessContext with the corresponding DPI_AWARENESS_CONTEXT value.

Note

It is recommended that you set the process-default DPI awareness via application manifest, not an API call. See Setting the default DPI awareness for a process for more information. Setting the process-default DPI awareness via API call can lead to unexpected application behavior.

Syntax

HRESULT SetProcessDpiAwareness(
  [in] PROCESS_DPI_AWARENESS value
);

Parameters

[in] value

The DPI awareness value to set. Possible values are from the PROCESS_DPI_AWARENESS enumeration.

Return value

This function returns one of the following values.

Return code	Description
S_OK	The DPI awareness for the app was set successfully.
E_INVALIDARG	The value passed in is not valid.
E_ACCESSDENIED	The DPI awareness is already set, either by calling this API previously or through the application (.exe) manifest.

Remarks

Previous versions of Windows only had one DPI awareness value for the entire application. For those applications, the recommendation was to set the DPI awareness value in the manifest as described in PROCESS_DPI_AWARENESS. Under that recommendation, you were not supposed to use SetProcessDpiAwareness to update the DPI awareness. In fact, future calls to this API would fail after the DPI awareness was set once. Now that DPI awareness is tied to a thread rather than an application, you can use this method to update the DPI awareness. However, consider using SetThreadDpiAwarenessContext instead.

Important  

For older applications, it is strongly recommended to not use SetProcessDpiAwareness to set the DPI awareness for your application. Instead, you should declare the DPI awareness for your application in the application manifest. See PROCESS_DPI_AWARENESS for more information about the DPI awareness values and how to set them in the manifest.

 

You must call this API before you call any APIs that depend on the dpi awareness. This is part of the reason why it is recommended to use the application manifest rather than the SetProcessDpiAwareness API. Once API awareness is set for an app, any future calls to this API will fail. This is true regardless of whether you set the DPI awareness in the manifest or by using this API.

If the DPI awareness level is not set, the default value is PROCESS_DPI_UNAWARE.

Requirements

Requirement	Value
Minimum supported client	Windows 8.1 [desktop apps only]
Minimum supported server	Windows Server 2012 R2 [desktop apps only]
Target Platform	Windows
Header	shellscalingapi.h
Library	Shcore.lib
DLL	Shcore.dll

See also

PROCESS_DPI_AWARENESS

SetThreadDpiAwarenessContext

Setting the default DPI awareness for a process