A swift 4 version
func addToolBar(textField: UITextView){
let toolBar = UIToolbar()
toolBar.barStyle = UIBarStyle.default
toolBar.isTranslucent = true
toolBar.tintColor = UIColor(red: 76/255, green: 217/255, blue: 100/255, alpha: 1)
let bold = UIBarButtonItem(image: #imageLiteral(resourceName: "download 12.01.19.png"), style: UIBarButtonItemStyle.done, target: self, action: #selector(boldFunc))
let italic = UIBarButtonItem(image: #imageLiteral(resourceName: "italic-png-image-54776.png"), style: UIBarButtonItemStyle.done, target: self, action: #selector(italicFunc))
let underlined = UIBarButtonItem(image: #imageLiteral(resourceName: "underlined_font-512.png"), style: UIBarButtonItemStyle.done, target: self, action: #selector(underlineFunc))
let strikeThrough = UIBarButtonItem(image: #imageLiteral(resourceName: "Strikethrough_font_awesome.svg.png"), style: UIBarButtonItemStyle.done, target: self, action: #selector(strikeFunc))
let size = UIBarButtonItem(title: "\(fontSize)", style: UIBarButtonItemStyle.done, target: self, action: #selector(changeSize))
let textColor = UIBarButtonItem(image: #imageLiteral(resourceName: "text_color1600.png"), style: UIBarButtonItemStyle.done, target: self, action: #selector(changetextColor))
let backgroundColor = UIBarButtonItem(image: #imageLiteral(resourceName: "background color.png"), style: UIBarButtonItemStyle.done, target: self, action: #selector(changebackgroundColor))
let textLeft = UIBarButtonItem(image: #imageLiteral(resourceName: "left-27877_960_720.png"), style: UIBarButtonItemStyle.done, target: self, action: #selector(alignLeft))
let textRight = UIBarButtonItem(image: #imageLiteral(resourceName: "align_right_filled1600.png"), style: UIBarButtonItemStyle.done, target: self, action: #selector(alignRight))
let textCenter = UIBarButtonItem(image: #imageLiteral(resourceName: "center.png"), style: UIBarButtonItemStyle.done, target: self, action: #selector(alignCenter))
let pic = UIBarButtonItem(image: #imageLiteral(resourceName: "add.png"), style: UIBarButtonItemStyle.done, target: self, action: #selector(appendPic))
let bulletpoint = UIBarButtonItem(image: #imageLiteral(resourceName: "bulletpoint.png"), style: UIBarButtonItemStyle.done, target: self, action: #selector(makeBulletpoints))
toolBar.setItems([bold, italic, underlined, strikeThrough, size, textColor, backgroundColor, textLeft, textRight, textCenter, pic, bulletpoint], animated: false)
toolBar.isUserInteractionEnabled = true
toolBar.sizeToFit()
toolBar.frame = CGRect(x: 0, y: 0, width: 33 * 12, height: toolBar.frame.size.height)
textField.delegate = self
//////////try to add a scroll view
let scrollView = UIScrollView()
scrollView.frame = toolBar.frame;
scrollView.bounds = toolBar.bounds;
scrollView.autoresizingMask = toolBar.autoresizingMask;
scrollView.showsVerticalScrollIndicator = false;
scrollView.showsHorizontalScrollIndicator = false;
scrollView.contentSize = toolBar.frame.size;
scrollView.addSubview(toolBar)
textField.inputAccessoryView = scrollView
}
when you calculate the width
toolBar.frame = CGRect(x: 0, y: 0, width: 33 * 12, height: toolBar.frame.size.height)
the width will depend on the size of the buttons you use. I had 12 buttons, all images on the buttons were 25 x 25, and there is one button with text. first I wrote 25 x 12 but they did not fit in, I think there are automatically some margins added, I did not go to much into detail on how the size of the buttons is calculated, so I just experimented till I found the number that worked well for me.