主要就是OS 12.1 Beta 2 引入的问题，只要 UITabBar 是磨砂的，并且 push viewController 时 hidesBottomBarWhenPushed = YES 则手势返回的时候就会触发。解决方法如下，在项目中添加一个UIView分类，在.m文件里设置好你的tabbar正确的尺寸，即可正常运行。
伸手党的快乐，拿走
.h文件
import <UIKit/UIKit.h>
NS_ASSUME_NONNULL_BEGIN
@interface UIView (LLTabBarItem)
@end
NS_ASSUME_NONNULL_END
.m文件
import "UIView+LLTabBarItem.h"
import <objc/runtime.h>
@implementation UIView (CKTabBarItem)
- (void)load
{
if (@available(iOS 12.1, *)) {
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Class class = NSClassFromString(@"UITabBarButton");
SEL originalSelector = @selector(setFrame:);
SEL swizzledSelector = @selector(ck_setFrame:);
Method originalMethod = class_getInstanceMethod(class, originalSelector);
Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);
BOOL isSuccess = class_addMethod(class,
originalSelector,
method_getImplementation(swizzledMethod),
method_getTypeEncoding(swizzledMethod));
if (isSuccess) {
class_replaceMethod(class,
swizzledSelector,
method_getImplementation(originalMethod),
method_getTypeEncoding(originalMethod));
} else {
method_exchangeImplementations(originalMethod, swizzledMethod);
}
});
}
}
- (void)ck_setFrame:(CGRect)frame
{
if (!CGRectIsEmpty(self.frame)) {
if (CGRectIsEmpty(frame)) {
return;
}
frame.size.height = MAX(frame.size.height, 60.0);
}
[self ck_setFrame: frame];
}
@end
