How to setting NavigationBar's barButtonItems - ios

Question

Now,I found the problem maybe from my custom button--DJExchangeImageTitleButton.This is the code:
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
[self setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
self.titleLabel.font = [UIFont boldSystemFontOfSize:15];
self.backgroundColor = [UIColor clearColor];
}
return self;
}
- (void)setFrame:(CGRect)frame
{
frame.size.width += DJMargin;
[super setFrame:frame];
}
- (void)layoutSubviews
{
[super layoutSubviews];
// 如果仅仅是调整按钮内部titleLabel和imageView的位置，那么在layoutSubviews中单独设置位置即可
// 1.计算titleLabel的frame
self.titleLabel.x = self.imageView.x;
// 2.计算imageView的frame
self.imageView.x = CGRectGetMaxX(self.titleLabel.frame) + DJMargin;
}
- (void)setTitle:(NSString *)title forState:(UIControlState)state
{
[super setTitle:title forState:state];
// 只要修改了文字，就让按钮重新计算自己的尺寸
[self sizeToFit];
}
- (void)setImage:(UIImage *)image forState:(UIControlState)state
{
[super setImage:image forState:state];
// 只要修改了图片，就让按钮重新计算自己的尺寸
[self sizeToFit];
}
-(void)setHighlighted:(BOOL)highlighted{};
Who can tell me what's wrong with my customed button?I will appreciate a lot.
When I set navigationBar's left,right and titleView,and it's normal;
However,every times,I push to another controller,and I pop back,the left and right barButtonItems become longer and longer,the titleView is shorter and shorter.
This is my code:
- (void)viewDidLoad {
[super viewDidLoad];
[self setupNaviBar];}
-(void)setupNaviBar{
//leftButton
DJExchangeImageTitleButton *titleBtn = [[DJExchangeImageTitleButton alloc]init];
[titleBtn setImage:[UIImage imageNamed:#"homgpage_navi_left"] forState:UIControlStateNormal];
[titleBtn setTitle:#"深圳" forState:UIControlStateNormal];
titleBtn.backgroundColor = [UIColor redColor];
titleBtn.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;
titleBtn.frame = CGRectMake(0, 0, 13, 25);
UIBarButtonItem *leftItem = [[UIBarButtonItem alloc]initWithCustomView:titleBtn];
UIBarButtonItem *negativeSpacer = [[UIBarButtonItem alloc]
initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace
target:nil action:nil];
negativeSpacer.width = -10;
self.navigationItem.leftBarButtonItems = #[negativeSpacer,leftItem];
//searchBar
UIButton *btn = [[UIButton alloc]init];
btn.backgroundColor = [UIColor whiteColor];
btn.frame = CGRectMake(0, 0, 250, 25);
btn.layer.cornerRadius = 3;
[btn setImage:[UIImage imageNamed:#"search_icon"] forState:UIControlStateNormal];
[btn setTitle:#"请输入要搜索的职位名称" forState:UIControlStateNormal];
[btn setTitleColor:[UIColor lightGrayColor] forState:UIControlStateNormal];
btn.titleLabel.font = [UIFont systemFontOfSize:13.0];
btn.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;
btn.imageEdgeInsets =UIEdgeInsetsMake(0, 10, 0, 0);
btn.titleEdgeInsets = UIEdgeInsetsMake(0, 15, 0, 0);
[btn addTarget:self action:#selector(goSearch) forControlEvents:UIControlEventTouchUpInside];
self.navigationItem.titleView = btn;
//rightButton
DJExchangeImageTitleButton *notiBtn = [[DJExchangeImageTitleButton alloc]init];
notiBtn.backgroundColor = [UIColor redColor];
[notiBtn setTitle:#"通知" forState:UIControlStateNormal];
[notiBtn setImage:[UIImage imageNamed:#"homgpage_navi_right"] forState:UIControlStateNormal];
notiBtn.contentHorizontalAlignment = UIControlContentHorizontalAlignmentRight;
notiBtn.frame = CGRectMake(0, 0, 13, 25);
UIBarButtonItem *right = [[UIBarButtonItem alloc]initWithCustomView:notiBtn];
self.navigationItem.rightBarButtonItem = right;
}
How can I solve this problem?Sorry I can't post a image to show my question.