這是最簡單方便的方法，我們可以使用runtime機制替換掉UILabel的初始化方法，在其中對label的字體進行默認設(shè)置。因為Label可以從initWithFrame、init和nib文件三個來源初始化，所以我們需要將這三個初始化的方法都替換掉。
#import@interface UILabel (QMChangeDefaultFont)
@end
#import "UILabel+QMChangeDefaultFont.h"
#import <objc/runtime.h>
#import@implementation UILabel (QMChangeDefaultFont)
/**
*每個NSObject的子類都會調(diào)用下面這個方法 在這里將init方法進行替換，使用我們的新字體
*如果在程序中又特殊設(shè)置了字體 則特殊設(shè)置的字體不會受影響 但是不要在Label的init方法中設(shè)置字體
*從init和initWithFrame和nib文件的加載方法 都支持更換默認字體
*/
+(void)load{
//只執(zhí)行一次這個方法
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Class class = [self class];
// When swizzling a class method, use the following:
// Class class = object_getClass((id)self);
//替換三個方法
SEL originalSelector = @selector(init);
SEL originalSelector2 = @selector(initWithFrame:);
SEL originalSelector3 = @selector(awakeFromNib);
SEL swizzledSelector = @selector(QMBaseInit);
SEL swizzledSelector2 = @selector(QMBaseInitWithFrame:);
SEL swizzledSelector3 = @selector(QMBaseAwakeFromNib);
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);
}
});
}
/**
*在這些方法中將你的字體名字換進去
*/
- (instancetype)QMBaseInit
{
id __self = [self QMBaseInit];
UIFont * font = [UIFont fontWithName:@"這里輸入你的字體名字" size:self.font.pointSize];
if (font) {
self.font=font;
}
return __self;
}
-(instancetype)QMBaseInitWithFrame:(CGRect)rect{
id __self = [self QMBaseInitWithFrame:rect];
UIFont * font = [UIFont fontWithName:@"這里輸入你的字體名字" size:self.font.pointSize];
if (font) {
self.font=font;
}
return __self;
}
-(void)QMBaseAwakeFromNib{
[self QMBaseAwakeFromNib];
UIFont * font = [UIFont fontWithName:@"這里輸入你的字體名字" size:self.font.pointSize];
if (font) {
self.font=font;
}
}
@end
/**
*每個NSObject的子類都會調(diào)用下面這個方法 在這里將init方法進行替換，使用我們的新字體
*如果在程序中又特殊設(shè)置了字體 則特殊設(shè)置的字體不會受影響 但是不要在Label的init方法中設(shè)置字體
*從init和initWithFrame和nib文件的加載方法 都支持更換默認字體
*/
