CGDisplayIOServicePort 在 OS X >= 10.9 中已弃用,如何替换?
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21-12-2019 - |
题
我做了一个小应用程序,可以快速更改多个显示器上的屏幕分辨率。我想将产品名称显示为显示器的标题,使用以下代码很容易找到:
NSDictionary *deviceInfo = (__bridge NSDictionary *)IODisplayCreateInfoDictionary(CGDisplayIOServicePort(dispID), kIODisplayOnlyPreferredName);
NSDictionary *localizedNames = [deviceInfo objectForKey:[NSString stringWithUTF8String:kDisplayProductName]];
if([localizedNames count] > 0) {
_title = [localizedNames objectForKey:[[localizedNames allKeys] objectAtIndex:0]];
} else {
_title = @"Unknown display";
}
但 CGDisplayIOServicePort
在 OS X >= 10.9 中已弃用,Apple 文档称没有替代品。不使用此方法如何找到服务端口或产品名称?
我尝试迭代 IO-registry 并尝试使用 IOServiceGetMatchingServices
查找显示服务的方法,但我对 IO-registry 不太熟悉,所以我找不到解决方案。
感谢帮助!
解决方案
看起来 @Eun 的帖子错过了一条结束此讨论的信息。经过一番搜索,我发现 IOServicePortFromCGDisplayID 不是 Apple 提供的 API。相反,它是在这里找到的一段开源代码:https://github.com/glfw/glfw/blob/e0a6772e5e4c672179fc69a90bcda3369792ed1f/src/cocoa_monitor.m
我从中复制了 IOServicePortFromCGDisplayID 和“getDisplayName”。我需要进行两项调整才能使其在 OS X 10.10 上运行。
- 删除 IOServicePortFromCGDisplayID 中处理序列号的代码。(kdisplayserialnumber的cfdictionarygetValue为我返回零。)
- 删除getDisplayName中的项目特定错误处理代码。
如果您需要更多信息
- 问题的问题跟踪器:github.com/glfw/glfw/issues/165
- 致力于解决方案:github.com/glfw/glfw/commit/e0a6772e5e4c672179fc69a90bcda3369792ed1f
我要感谢 Matthew Henry 在那里提交了代码。
其他提示
这是我对这个问题的看法。我还从 GLFW 3.1 的代码(文件 cocoa_monitor.m)开始。
但我必须以与 Hiroshi 所说不同的方式修改它,所以这里是:
// Get the name of the specified display
- (NSString*) screenNameForDisplay: (NSNumber*) screen_id
{
CGDirectDisplayID displayID = [screen_id unsignedIntValue];
io_service_t serv = [self IOServicePortFromCGDisplayID: displayID];
if (serv == 0)
return @"unknown";
CFDictionaryRef info = IODisplayCreateInfoDictionary(serv, kIODisplayOnlyPreferredName);
IOObjectRelease(serv);
CFStringRef display_name;
CFDictionaryRef names = CFDictionaryGetValue(info, CFSTR(kDisplayProductName));
if ( !names ||
!CFDictionaryGetValueIfPresent(names, CFSTR("en_US"), (const void**) & display_name) )
{
// This may happen if a desktop Mac is running headless
CFRelease( info );
return @"unknown";
}
NSString * displayname = [NSString stringWithString: (__bridge NSString *) display_name];
CFRelease(info);
return displayname;
}
// Returns the io_service_t (an int) corresponding to a CG display ID, or 0 on failure.
// The io_service_t should be released with IOObjectRelease when not needed.
- (io_service_t) IOServicePortFromCGDisplayID: (CGDirectDisplayID) displayID
{
io_iterator_t iter;
io_service_t serv, servicePort = 0;
CFMutableDictionaryRef matching = IOServiceMatching("IODisplayConnect");
// releases matching for us
kern_return_t err = IOServiceGetMatchingServices( kIOMasterPortDefault, matching, & iter );
if ( err )
return 0;
while ( (serv = IOIteratorNext(iter)) != 0 )
{
CFDictionaryRef displayInfo;
CFNumberRef vendorIDRef;
CFNumberRef productIDRef;
CFNumberRef serialNumberRef;
displayInfo = IODisplayCreateInfoDictionary( serv, kIODisplayOnlyPreferredName );
Boolean success;
success = CFDictionaryGetValueIfPresent( displayInfo, CFSTR(kDisplayVendorID), (const void**) & vendorIDRef );
success &= CFDictionaryGetValueIfPresent( displayInfo, CFSTR(kDisplayProductID), (const void**) & productIDRef );
if ( !success )
{
CFRelease(displayInfo);
continue;
}
SInt32 vendorID;
CFNumberGetValue( vendorIDRef, kCFNumberSInt32Type, &vendorID );
SInt32 productID;
CFNumberGetValue( productIDRef, kCFNumberSInt32Type, &productID );
// If a serial number is found, use it.
// Otherwise serial number will be nil (= 0) which will match with the output of 'CGDisplaySerialNumber'
SInt32 serialNumber = 0;
if ( CFDictionaryGetValueIfPresent(displayInfo, CFSTR(kDisplaySerialNumber), (const void**) & serialNumberRef) )
{
CFNumberGetValue( serialNumberRef, kCFNumberSInt32Type, &serialNumber );
}
// If the vendor and product id along with the serial don't match
// then we are not looking at the correct monitor.
// NOTE: The serial number is important in cases where two monitors
// are the exact same.
if( CGDisplayVendorNumber(displayID) != vendorID ||
CGDisplayModelNumber(displayID) != productID ||
CGDisplaySerialNumber(displayID) != serialNumber )
{
CFRelease(displayInfo);
continue;
}
servicePort = serv;
CFRelease(displayInfo);
break;
}
IOObjectRelease(iter);
return servicePort;
}
这对于我在 macOS 10.11 (El Capitan) 下编写的屏幕保护程序来说效果很好。我使用 MacBookPro 的内置显示屏和通过 Thunderbolt 连接的 Apple 显示屏对其进行了测试。
NSString* screenNameForDisplay(CGDirectDisplayID displayID)
{
NSString *screenName = nil;
io_service_t service = IOServicePortFromCGDisplayID(displayID);
if (service)
{
NSDictionary *deviceInfo = (NSDictionary *)IODisplayCreateInfoDictionary(service, kIODisplayOnlyPreferredName);
NSDictionary *localizedNames = [deviceInfo objectForKey:[NSString stringWithUTF8String:kDisplayProductName]];
if ([localizedNames count] > 0) {
screenName = [[localizedNames objectForKey:[[localizedNames allKeys] objectAtIndex:0]] retain];
}
[deviceInfo release];
}
return [screenName autorelease];
}