/// <summary>
/// Initializes a new instance of the <see cref="DpiAwarenessScope"/> class, and sets the current thread's
/// DPI_AWARENESS_CONTEXT to the value requested by <paramref name="dpiAwarenessContextValue"/>
/// </summary>
/// <param name="dpiAwarenessContextValue">New DPI awareness value</param>
/// <param name="updateIfThreadInMixedHostingMode">When true, the current thread is switched to the new mode iff the current thread is already in mixed hosting mode</param>
/// <param name="updateIfWindowIsSystemAwareOrUnaware">When true, the current thread is switched to the new mode iff <paramref name="hWnd"/> is in System Aware or Unaware DPI mode</param>
/// <param name="hWnd">Window which is tested in conjunction with <paramref name="updateIfWindowIsSystemAwareOrUnaware"/></param>
private DpiAwarenessScope(
DpiAwarenessContextValue dpiAwarenessContextValue,
bool updateIfThreadInMixedHostingMode,
bool updateIfWindowIsSystemAwareOrUnaware,
IntPtr hWnd)
{
if (!OperationSupported)
{
return;
}
if (updateIfThreadInMixedHostingMode && !this.IsThreadInMixedHostingBehavior)
{
return;
}
if (updateIfWindowIsSystemAwareOrUnaware &&
(hWnd == IntPtr.Zero || !this.IsWindowUnawareOrSystemAware(hWnd)))
{
return;
}
try
{
this.OldDpiAwarenessContext =
UnsafeNativeMethods.SetThreadDpiAwarenessContext(
new DpiAwarenessContextHandle(dpiAwarenessContextValue));
}
catch (Exception e) when(e is EntryPointNotFoundException || e is MissingMethodException || e is DllNotFoundException)
{
OperationSupported = false;
}
}
/// <summary>
/// Initializes a new instance of the <see cref="DpiAwarenessScope"/> class, and sets the current thread's
/// DPI_AWARENESS_CONTEXT to the value requested by <paramref name="dpiAwarenessContextEnumValue"/>
/// </summary>
/// <param name="dpiAwarenessContextEnumValue">DPI_AWARENESS_CONTEXT to set the thread to</param>
public DpiAwarenessScope(DpiAwarenessContextValue dpiAwarenessContextEnumValue)
: this(
dpiAwarenessContextEnumValue,
updateIfThreadInMixedHostingMode : false,
updateIfWindowIsSystemAwareOrUnaware : false,
hWnd : IntPtr.Zero)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="DpiAwarenessScope"/> class, and sets the current thread's
/// DPI_AWARENESS_CONTEXT to the value requested by <paramref name="dpiAwarenessContextEnumValue"/>
/// </summary>
/// <param name="dpiAwarenessContextEnumValue">New DPI awareness value</param>
/// <param name="updateIfThreadInMixedHostingMode">
/// When true, checks whether the current thread is in mixed hosting mode,
/// and only then switches the thread to the new mode
/// </param>
/// <param name="hWnd">
/// The window which is tested to see whether it is in mixed hosting mode.
/// Only if the window is found to be in mixed hosting mode is the current threads DPI awareness context
/// switched to the new value
/// </param>
public DpiAwarenessScope(
DpiAwarenessContextValue dpiAwarenessContextEnumValue, bool updateIfThreadInMixedHostingMode, IntPtr hWnd)
: this(
dpiAwarenessContextEnumValue,
updateIfThreadInMixedHostingMode : updateIfThreadInMixedHostingMode,
updateIfWindowIsSystemAwareOrUnaware : true,
hWnd : hWnd)
{
}
/// <summary>
/// Helper to modify the DPI_AWARENESS_CONTEXT of the current thread.
/// </summary>
/// <param name="dpiAwarenessContext">DPI_AWARENESS_CONTEXT to set the thread to</param>
/// <returns>
/// An <see cref="IDisposable"/> that defines a scope during which the DPI_AWARENESS_CONTEXT of the current thread is
/// modified to the requested value.
/// </returns>
internal static IDisposable WithDpiAwarenessContext(DpiAwarenessContextValue dpiAwarenessContext)
{
return(new DpiAwarenessScope(dpiAwarenessContext));
}
internal DpiAwarenessContextHandle(DpiAwarenessContextValue dpiAwarenessContextValue)
: base(WellKnownContextValues[dpiAwarenessContextValue], false)
{
}
/// <summary>
/// Equality comparison
/// </summary>
/// <param name="dpiContextEnumValue">DPI context enumeration value being compared against</param>
/// <returns>True if equivalent to the DPI context enum value, otherwise False</returns>
public bool Equals(DpiAwarenessContextValue dpiContextEnumValue)
{
return(this.Equals(WellKnownContextValues[dpiContextEnumValue]));
}
