iOS中Navigation中添加自定义Button等UIView

NSInteger width = [[UIScreen mainScreen]bounds].size.width - 20;　　//获取系统的width
UIView *view_title = [[UIView alloc]initWithFrame:CGRectMake(width, 10, 20, 20)]; //生成自定义UIView
UIButton *btnItem = [[UIButton alloc]initWithFrame:CGRectMake(0, 0, 20, 20)];
UIImage *image = [UIImage imageNamed:@"down.png"];
[btnItem setImage:image forState:UIControlStateNormal];
[btnItem addTarget:self action:@selector(favoriteBtnItem) forControlEvents:UIControlEventTouchUpInside];

[view_title addSubview:btnItem];

//将UIView添加到UIBarBtn中

UIBarButtonItem *btn =[[UIBarButtonItem alloc]initWithCustomView:view_title];

//设置成右边按钮位置
self.navigationItem.rightBarButtonItem = btn;