全局配置UIFont

全局修改UIFont，根据屏幕适配字体大小

#import "UILabel+YQFont.h"
#import <objc/runtime.h>

@implementation UILabel (YQFont)

+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        Class class = [self class];
        //替换三个方法
        SEL originalSelector = @selector(init);
        SEL originalSelector2 = @selector(initWithFrame:);
        SEL originalSelector3 = @selector(awakeFromNib);
        SEL swizzledSelector = @selector(YQBaseInit);
        SEL swizzledSelector2 = @selector(YQBaseInitWithFrame:);
        SEL swizzledSelector3 = @selector(YQBaseAwakeFromNib);
        
        Method originalMethod = class_getInstanceMethod(class, originalSelector);
        Method originalMethod2 = class_getInstanceMethod(class, originalSelector2);
        Method originalMethod3 = class_getInstanceMethod(class, originalSelector3);
        Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);
        Method swizzledMethod2 = class_getInstanceMethod(class, swizzledSelector2);
        Method swizzledMethod3 = class_getInstanceMethod(class, swizzledSelector3);
        BOOL didAddMethod =
        class_addMethod(class,
                        originalSelector,
                        method_getImplementation(swizzledMethod),
                        method_getTypeEncoding(swizzledMethod));
        BOOL didAddMethod2 =
        class_addMethod(class,
                        originalSelector2,
                        method_getImplementation(swizzledMethod2),
                        method_getTypeEncoding(swizzledMethod2));
        BOOL didAddMethod3 =
        class_addMethod(class,
                        originalSelector3,
                        method_getImplementation(swizzledMethod3),
                        method_getTypeEncoding(swizzledMethod3));
        
        if (didAddMethod) {
            class_replaceMethod(class,
                                swizzledSelector,
                                method_getImplementation(originalMethod),
                                method_getTypeEncoding(originalMethod));
            
        } else {
            method_exchangeImplementations(originalMethod, swizzledMethod);
        }
        if (didAddMethod2) {
            class_replaceMethod(class,
                                swizzledSelector2,
                                method_getImplementation(originalMethod2),
                                method_getTypeEncoding(originalMethod2));
        }else {
            method_exchangeImplementations(originalMethod2, swizzledMethod2);
        }
        if (didAddMethod3) {
            class_replaceMethod(class,
                                swizzledSelector3,
                                method_getImplementation(originalMethod3),
                                method_getTypeEncoding(originalMethod3));
        }else {
            method_exchangeImplementations(originalMethod3, swizzledMethod3);
        }
    });
    
}
/**
 *在这些方法中将你的字体名字换进去
 */
- (instancetype)YQBaseInit
{
    id __self = [self YQBaseInit];
    [self changeFont];
    return __self;
}

-(instancetype)YQBaseInitWithFrame:(CGRect)rect{
    id __self = [self YQBaseInitWithFrame:rect];
    [self changeFont];
    return __self;
}

-(void)YQBaseAwakeFromNib{
    [self YQBaseAwakeFromNib];
    [self changeFont];
}

- (void)changeFont {
    BOOL isBold = [self isBoldWithFontDescriptor:self.font.fontDescriptor];
    UIFont *font = isBold ? [UIFont boldSystemFontOfSize:RealFont(self.font.pointSize)] : [UIFont systemFontOfSize:RealFont(self.font.pointSize)];
    if (font) {
        self.font=font;
    }
}

// 获取Xib中字体是否是加粗字体
- (BOOL)isBoldWithFontDescriptor:(UIFontDescriptor *)fontDesc {
    NSString *str = fontDesc.postscriptName;
    BOOL isBold = NO;
    if ([[str lowercaseString] containsString:@"bold"]) {
        isBold = YES;
    }
    return isBold;
}

@end