一：自定义titleHeadView  ，

titleHeadView.h中：

@property(nonatomic, assign) CGSize intrinsicContentSize;

headView = [[titleHeadView alloc]init];

    headView.intrinsicContentSize = CGSizeMake(Screen_Width-100, 28);

    headView.translatesAutoresizingMaskIntoConstraints = false;

    headView.backgroundColor = [UIColor clearColor];

    searchtextFiled = [[UITextField alloc]initWithFrame:CGRectMake(0, 0, Screen_Width-100, 28)];

    searchtextFiled.placeholder = @"请输入搜索关键字";

    searchtextFiled.clearButtonMode = UITextFieldViewModeWhileEditing;

    searchtextFiled.textColor =  [UIColor colorWithHexString:@"969696"];

    searchtextFiled.font = [UIFont systemFontOfSize:13];

    searchtextFiled.borderStyle = UITextBorderStyleRoundedRect;

    searchtextFiled.backgroundColor = [UIColor whiteColor];

    searchtextFiled.returnKeyType = UIReturnKeySearch;

    searchtextFiled.delegate = self;

    [headView addSubview:searchtextFiled];

    self.navigationItem.titleView = headView;

看不明白的可以加我主页的QQ。