/// <summary>
/// Get the Effective DPI of a monitor after a user's accessibility
/// preferences have been applied.
/// </summary>
/// <param name="hMonitor">The monitor.</param>
/// <param name="dpiX">The dpi x.</param>
/// <param name="dpiY">The dpi y.</param>
public static void GetMonitorEffectiveDpi(IntPtr hMonitor, out uint dpiX, out uint dpiY)
{
dpiX = _defaultPixelsPerInch;
dpiY = _defaultPixelsPerInch;
ProcessDpiAwareness awareness = DpiAwareness;
if (awareness >= ProcessDpiAwareness.PerMonitorDpiAware)
{
int hresult = NativeMethods.GetDpiForMonitor(hMonitor,
NativeMethods.Monitor_DPI_Type.MDT_Effective_DPI, ref dpiX, ref dpiY);
if (hresult != 0)
{
// If anything goes wrong, return a reasonable default
dpiX = _defaultPixelsPerInch;
dpiY = _defaultPixelsPerInch;
}
}
else if (awareness == ProcessDpiAwareness.SystemDpiAware)
{
GetSystemEffectiveDpi(out dpiX, out dpiY);
}
else
{
// Use the default of 96
return;
}
}
private static ProcessDpiAwareness GetDpiAwareness()
{
//return ProcessDpiAwareness.PerMonitorDpiAware;
ProcessDpiAwareness result = ProcessDpiAwareness.DpiUnaware;
try
{
// If at least Windows 8.1
if (IsOsGreaterOrEqualTo(6, 3))
{
int value = 0;
if (NativeMethods.GetProcessDpiAwareness(IntPtr.Zero, ref value) == 0)
{
result = (ProcessDpiAwareness)value;
}
}
}
catch
{
result = ProcessDpiAwareness.DpiUnaware;
}
return(result);
}
public static void SetDpiAware(ProcessDpiAwareness value)
{
if (Platform.OperatingSystem == OS.Windows)
{
if (Platform.OperatingSystemVersion >= Platform.Windows8_1)
{
var result = NativeMethods.SetProcessDpiAwareness(value);
if (result != HRESULT.Ok)
{
Console.WriteLine("Failed to set application to be DPI aware: " + result);
}
}
else if (Platform.OperatingSystemVersion >= Platform.WindowsVista)
{
// This platform only supports system dpi awareness.
if (!NativeMethods.SetProcessDPIAware())
{
Console.WriteLine("Failed to set application to be DPI aware.");
}
}
else
{
Console.WriteLine("This platform does not support DPI awareness.");
}
}
}
public static ProcessDpiAwareness GetProcessDpiAwareness(IntPtr handle)
{
ProcessDpiAwareness pda = ProcessDpiAwareness.Unaware;
if (GetProcessDpiAwareness(handle, ref pda) == 0)
{
return(pda);
}
return(ProcessDpiAwareness.Unaware);
}
/// <summary>
/// Set DPI Awareness
/// </summary>
/// <param name="dpiAwareness"></param>
/// <returns>true on success</returns>
public static bool SetDpiAwareness(ProcessDpiAwareness dpiAwareness)
{
try
{
return(NativeMethods.SetProcessDpiAwareness(dpiAwareness));
}
catch (DllNotFoundException)
{
// DPI Awareness API is not available on older OS's, but they work in
// physical pixels anyway, so we just ignore if the call fails.
}
return(false);
}
/// <summary>
/// IMPORTANT: This only works if this is called in the immediate startup code
/// of the application. For WPF this means `static App() { }`.
/// </summary>
public static bool SetPerMonitorDpiAwareness(ProcessDpiAwareness type = ProcessDpiAwareness.Process_Per_Monitor_DPI_Aware)
{
try
{
// for this to work make sure [assembly: DisableDpiAwareness]
ProcessDpiAwareness awarenessType;
GetProcessDpiAwareness(Process.GetCurrentProcess().Handle, out awarenessType);
var result = SetProcessDpiAwareness(type);
GetProcessDpiAwareness(Process.GetCurrentProcess().Handle, out awarenessType);
return(awarenessType == type);
}
catch
{
return(false);
}
}
/// <summary>
/// Attempts to set the DPI awareness of this process to PerMonitorDpiAware
/// </summary>
/// <returns>A value indicating whether the DPI awareness has been set to PerMonitorDpiAware.</returns>
/// <remarks>
/// <para>
/// For this operation to succeed the host OS must be Windows 8.1 or greater, and the initial
/// DPI awareness must be set to DpiUnaware (apply [assembly:DisableDpiAwareness] to application assembly).
/// </para>
/// <para>
/// When the host OS is Windows 8 or lower, an attempt is made to set the DPI awareness to SystemDpiAware (= WPF
/// default). This
/// effectively revokes the [assembly:DisableDpiAwareness] attribute if set.
/// </para>
/// </remarks>
public static bool TrySetPerMonitorDpiAware()
{
ProcessDpiAwareness awareness = GetDpiAwareness();
// initial awareness must be DpiUnaware
if (awareness == ProcessDpiAwareness.DpiUnaware)
{
if (OSVersionHelper.IsWindows8Point1OrGreater)
{
return(NativeMethods.SetProcessDpiAwareness(ProcessDpiAwareness.PerMonitorDpiAware) ==
NativeMethods.S_OK);
}
// use older Win32 API to set the awareness to SystemDpiAware
return(NativeMethods.SetProcessDPIAware() == NativeMethods.S_OK);
}
// return true if per monitor was already enabled
return(awareness == ProcessDpiAwareness.PerMonitorDpiAware);
}
public static void SetDpiAware(ProcessDpiAwareness value)
{
if (Environment.OSVersion.Version >= new Version(6, 3) /* Windows 8.1 */)
{
var result = NativeMethods.SetProcessDpiAwareness(value);
if (result != HRESULT.Ok)
{
Console.WriteLine("Failed to set application to be DPI aware: " + result);
}
}
else if (Environment.OSVersion.Version >= new Version(6, 0) /* Windows Vista */)
{
// This platform only supports system dpi awareness.
if (!NativeMethods.SetProcessDPIAware())
{
Console.WriteLine("Failed to set application to be DPI aware.");
}
}
else
{
Console.WriteLine("This platform does not support DPI awareness.");
}
}
private static extern void GetProcessDpiAwareness(IntPtr hprocess, out ProcessDpiAwareness awareness);
private static extern bool SetProcessDpiAwareness(ProcessDpiAwareness awareness);
internal static extern bool SetProcessDpiAwareness(ProcessDpiAwareness awareness);
internal static extern int SetProcessDpiAwareness(
[MarshalAs(UnmanagedType.U4)] ProcessDpiAwareness a);
private static extern int GetProcessDpiAwareness(IntPtr handle, ref ProcessDpiAwareness awareness);
public static extern int SetProcessDpiAwareness(ProcessDpiAwareness awareness);
public static extern HRESULT SetProcessDpiAwareness(ProcessDpiAwareness value);
public static extern int GetProcessDpiAwareness(IntPtr hprocess, out ProcessDpiAwareness value);
public static extern int SetProcessDpiAwareness(ProcessDpiAwareness value);
public static extern int SetProcessDpiAwareness(ProcessDpiAwareness value);
public static extern int GetProcessDpiAwareness(IntPtr processHandle, out ProcessDpiAwareness processDpiAwareness);
public static extern int GetProcessDpiAwareness(IntPtr hprocess, out ProcessDpiAwareness value);
private static extern void _GetProcessDpiAwareness(IntPtr hProcess, out ProcessDpiAwareness value); // Windows 8.1 and above
private static extern bool SetProcessDpiAwareness(ProcessDpiAwareness value);
internal static extern uint GetProcessDpiAwareness(IntPtr process, out ProcessDpiAwareness awareness);