#import "UIViewController+Parents.h"
/** 导入头文件 */
#import <objc/runtime.h>
@implementation UIViewController (Parents)
//load方法会在类第一次加载的时候被调用
//调用的时间比较靠前，适合在这个方法里做方法交换
+ (void)load{
//方法交换应该被保证，在程序中只会执行一次
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
//获得viewController的生命周期方法的selector
SEL systemSel = @selector(viewDidDisappear:);
//自己实现的将要被交换的方法的selector
SEL swizzSel = @selector(swiz_viewDidDisappear:);
//两个方法的Method
Method systemMethod = class_getInstanceMethod([self class], systemSel);
Method swizzMethod = class_getInstanceMethod([self class], swizzSel);
//首先动态添加方法，实现是被交换的方法，返回值表示添加成功还是失败
BOOL isAdd = class_addMethod(self, systemSel, method_getImplementation(swizzMethod), method_getTypeEncoding(swizzMethod));
if (isAdd) {
//如果成功，说明类中不存在这个方法的实现
//将被交换方法的实现替换到这个并不存在的实现
class_replaceMethod(self, swizzSel, method_getImplementation(systemMethod), method_getTypeEncoding(systemMethod));
}else{
//否则，交换两个方法的实现
method_exchangeImplementations(systemMethod, swizzMethod);
}
});
}
- (void)swiz_viewDidDisappear:(BOOL)animated{
//这时候调用自己，看起来像是死循环
//但是其实自己的实现已经被替换了
[self swiz_viewDidDisappear:animated];
[self setExclusiveTouchForButtons:self.view];
NSLog(@"swizzle");
}
-(void)setExclusiveTouchForButtons:(UIView *)myView
{
for (UIView * v in [myView subviews]) {
if([v isKindOfClass:[UIButton class]])
[((UIButton *)v) setExclusiveTouch:YES];
else if ([v isKindOfClass:[UIView class]]){
[self setExclusiveTouchForButtons:v];
}
}
}