iOS UITableView的Section Footer加入button

- (CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section
{
if (section >= kSetSetting) {
return 80;
}
else{
return 2;
}
}

- (UIView *)tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section
{
if (section >= kSetSetting)
{
UIView *footerView = [[UIView alloc] init];
footerView.userInteractionEnabled = YES;
footerView.backgroundColor = [UIColor clearColor];

UIButton *loginButton = [UIButton buttonWithType:UIButtonTypeSystem];
[loginButton.layer setMasksToBounds:YES];
[loginButton.layer setCornerRadius:5.0];
[loginButton setBackgroundColor:[UIColor brownColor]];
[loginButton setTitle:@"登陆" forState:UIControlStateNormal];
[loginButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[loginButton.titleLabel setFont:[UIFont systemFontOfSize:15]];
[loginButton setTranslatesAutoresizingMaskIntoConstraints:NO];
[loginButton addTarget:self action:@selector(loginBtnClick:) forControlEvents:UIControlEventTouchUpInside];
//[footerView addSubview:btnExit];

[footerView addSubview:loginButton];

UIButton *registerButton = [UIButton buttonWithType:UIButtonTypeSystem];
[registerButton.layer setMasksToBounds:YES];
[registerButton.layer setCornerRadius:5.0];
[registerButton setBackgroundColor:[UIColor brownColor]];
[registerButton setTitle:@"注冊" forState:UIControlStateNormal];
[registerButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[registerButton.titleLabel setFont:[UIFont systemFontOfSize:15]];
[registerButton setTranslatesAutoresizingMaskIntoConstraints:NO];
[registerButton addTarget:self action:@selector(registerBtnClick:) forControlEvents:UIControlEventTouchUpInside];
[footerView addSubview:registerButton];

NSDictionary *constraintsView = NSDictionaryOfVariableBindings(loginButton,registerButton);

[footerView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-15-[loginButton]-15-|"  options:0 metrics:nil views:constraintsView ]];
[footerView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"|-20-[loginButton]"    options:0 metrics:nil views:constraintsView ]];

[footerView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-15-[registerButton(==loginButton)]-15-|"  options:0 metrics:nil views:constraintsView ]];
[footerView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:[loginButton]-30-[registerButton(==loginButton)]-20-|"    options:0 metrics:nil views:constraintsView]];

return footerView;
}
else
{
return nil;
}
}