iOS设置[self.navigationItem setTitleView:View]

自定义NavigationBar

功能需求在NavigationBar上添加搜索框，并对其位置提出了要求，系统中自带的TitleView不能满足，因此查阅了资料，重写了TitleView

TitleView.h文件,重写TitleView继承UIView

#import 

@interface TitleView : UIView

@end

TitleView.m文件,重写其父类的Frame

#import "TitleView.h"

@implementation TitleView
- (instancetype)initWithFrame:(CGRect)frame {

    self = [super initWithFrame:frame];
    if (self) {

    }
    return self;
}

- (void)setFrame:(CGRect)frame {

    [super setFrame:CGRectMake(0, 0, self.superview.frame.size.width, self.superview.bounds.size.height)];
}
@end

---

在需要使用的地方引用

    // 这里之所以要把leftBarButtonItem的title = @“”，设为了防止界面从上一层pushViewController：或是从该界面popViewControllerAnimated：是显示出系统自带的返回箭头
    UIBarButtonItem * backButtonItem = [[UIBarButtonItem alloc] init];
    [backButtonItem setTitle:@""];
    self.navigationItem.leftBarButtonItem = backButtonItem;

    _titleView = [[TitleView alloc] initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, 44)];
    _titleView.backgroundColor = [UIColor blackColor];
    self.navigationItem.titleView = _titleView;