问题
What winapi's are there to change the screen's brightness?
I've been attempting to look for an example or API I can use for Delphi but have not found anything.
回答1:
Starting with Windows Vista you can use the GetMonitorBrightness and SetMonitorBrightness functions.
function GetMonitorBrightness(
hMonitor : THandle;
var pdwMinimumBrightness : DWORD;
var pdwCurrentBrightness : DWORD;
var pdwMaximumBrightness : DWORD
) : BOOL; stdcall ; external 'Dxva2.dll' name 'GetMonitorBrightness';
function SetMonitorBrightness(
hMonitor : THandle;
dwNewBrightness : DWORD
): BOOL; stdcall ; external 'Dxva2.dll' name 'SetMonitorBrightness';
Another option is use the WmiSetBrightness method of the WmiMonitorBrightnessMethods WMI Class.
{$APPTYPE CONSOLE}
uses
SysUtils,
ActiveX,
Variants,
ComObj;
procedure SetBrightness(Timeout : Integer; Brightness : Byte);
var
FSWbemLocator : OLEVariant;
FWMIService : OLEVariant;
FWbemObjectSet: OLEVariant;
FWbemObject : OLEVariant;
oEnum : IEnumvariant;
iValue : LongWord;
begin;
FSWbemLocator := CreateOleObject('WbemScripting.SWbemLocator');
FWMIService := FSWbemLocator.ConnectServer('localhost', 'root\WMI', '', '');
FWbemObjectSet:= FWMIService.ExecQuery('SELECT * FROM WmiMonitorBrightnessMethods Where Active=True','WQL',$00000020);
oEnum := IUnknown(FWbemObjectSet._NewEnum) as IEnumVariant;
while oEnum.Next(1, FWbemObject, iValue) = 0 do
begin
FWbemObject.WmiSetBrightness(Timeout, Brightness);
FWbemObject:=Unassigned;
end;
end;
begin
try
CoInitialize(nil);
try
SetBrightness(5, 100);
finally
CoUninitialize;
end;
except
on E:EOleException do
Writeln(Format('EOleException %s %x', [E.Message,E.ErrorCode]));
on E:Exception do
Writeln(E.Classname, ':', E.Message);
end;
Writeln('Press Enter to exit');
Readln;
end.
Note: These functions are supported if the GetMonitorCapabilities function returns the MC_CAPS_BRIGHTNESS flag.
来源:https://stackoverflow.com/questions/16027126/winapi-change-brightness