UIButton not displayed - ios

Question

I use the following code to add a UIButton and a UITableView to a UIViewController:
self.tableView = ({
UITableView *tableView = [[UITableView alloc] initWithFrame:CGRectZero style:UITableViewStylePlain];
tableView.translatesAutoresizingMaskIntoConstraints = NO;
tableView.scrollEnabled = NO;
tableView.allowsSelection = NO;
tableView.dataSource = self;
tableView.delegate = self;
tableView;
});
self.refreshButton = ({
UIButton *button = [UIButton new];
button.translatesAutoresizingMaskIntoConstraints = NO;
[button setTitle:#"testtest" forState:UIControlStateNormal];
[button addTarget:self
action:#selector(clickRefreshButton)
forControlEvents:UIControlEventTouchUpInside];
button.titleLabel.numberOfLines = 1;
button.titleLabel.textAlignment = NSTextAlignmentRight;
button.titleLabel.adjustsFontSizeToFitWidth = NO;
button.alpha = 1.0;
button;
});
[self.view addSubview:self.tableView];
[self.view addSubview:self.refreshButton];
CGFloat tableViewUpPadding = 20.0f;
CGFloat navigationBarHeight = self.navigationController.navigationBar.frame.size.height;
CGFloat tabBarHeight = self.tabBarController.tabBar.frame.size.height;
CGFloat buttonOffset = 10.0f;
CGFloat buttonSideLength = 50.0f;
[self.tableView mas_makeConstraints:^(MASConstraintMaker *make){
make.top.equalTo(self.view.mas_top).offset(tableViewUpPadding);
make.bottom.equalTo(self.view.mas_bottom).offset(-tabBarHeight);
make.width.equalTo(self.view.mas_width);
make.left.equalTo(self.view.mas_left);
}];
[self.refreshButton mas_makeConstraints:^(MASConstraintMaker *make){
make.right.equalTo(self.view.mas_right).offset(-buttonOffset);
make.bottom.equalTo(self.view.mas_bottom).offset(-buttonOffset);
make.width.equalTo(#(buttonSideLength));
make.height.equalTo(#(buttonSideLength));
}];
Among which I use masonry to do auto-layout. However when I run the app the button doesn't appear, and not even in view debugging area.. Can somebody tell me why?
Or if I use strings and struts to create button, it still won't show :(
CGRect applicationFrame = [UIScreen mainScreen].bounds;
CGFloat screenWidth = CGRectGetWidth(applicationFrame);
CGFloat screenHeight = CGRectGetHeight(applicationFrame);
CGFloat buttonWidth = 40.0f;
CGFloat buttonHeight = 40.0f;
CGFloat spacing = 10.0f;
CGFloat buttonX = screenWidth - buttonWidth - spacing;
CGFloat buttonY = screenHeight - buttonHeight - spacing;
CGRect buttonFrame = CGRectMake(buttonX, buttonY, buttonWidth, buttonHeight);
[self.refreshButton setFrame:buttonFrame];
By the way, I found that if I want to change self.tableView's width using auto-layout, it's also impossible:
[self.tableView mas_makeConstraints:^(MASConstraintMaker *make){
make.top.equalTo(self.view.mas_top).offset(tableViewUpPadding);
make.bottom.equalTo(self.view.mas_bottom).offset(-tabBarHeight);
make.width.equalTo(self.view.as_width).offset(-offset);
make.left.equalTo(self.view.mas_left);
}];
It turns out that the tableview is still as wide as self.view