如何确定在Objective-C中的Mac OSX计算机上是否安装了NSFont？

#import <AppKit/AppKit.h>

NSArray *fontNames = [[NSFontManager sharedFontManager] availableFontNames];

BOOL isNSFontInstalled = NO;
for (NSString *fontName in fontNames) {
    if ([fontName isEqualToString:@"NSFont"]) {
        isNSFontInstalled = YES;
        break;
    }
}

#import <AppKit/AppKit.h>

BOOL isNSFontInstalled(void) {
    NSArray *fontNames = [[NSFontManager sharedFontManager] availableFontNames];
    BOOL isNSFontInstalled = NO;
    for (NSString *fontName in fontNames) {
        if ([fontName isEqualToString:@"NSFont"]) {
            isNSFontInstalled = YES;
            break;
        }
    }
    return isNSFontInstalled;
}