Q:

It's hard to click on Bar button Item

I've created custom back bar button. And I added an UIview because I have to change position of it within bar.
UIImage *backButtonImage = [UIImage imageNamed:@"backBtnWhite"];

_backButton = [UIButton buttonWithType:UIButtonTypeCustom];
_backButton.exclusiveTouch = YES;
[_backButton setImage:backButtonImage forState:UIControlStateNormal];
[_backButton setImage:backButtonImage forState:UIControlStateHighlighted];
[_backButton addTarget:self action:@selector(back) forControlEvents:UIControlEventTouchUpInside];
_backButton.frame = CGRectMake(-4.0, 7.0, 40, 40);

UIView * view = [[UIView alloc] initWithFrame:CGRectMake(-4.0, 7.0, backButtonImage.size.width, backButtonImage.size.height)];
[view addSubview:_backButton];

UIBarButtonItem* barButtonItem = [[UIBarButtonItem alloc] initWithCustomView:view];
self.navigationItem.rightBarButtonItem = barButtonItem;

But after that I've added UIView it became difficult to click on it.
I've tried to change button area, but it didn't give results.

A:

It seems like you specify incorrect frame for _button or/and view and this changes the tap region. Try to set different background color for _backButton and view. This will show you if frames are in positions that you expect. 
If you try to adjust image position by specifying these frames - its more correct to use properties of UIButton like imageEdgeInsets and titleEdgeInsets.

