使用 swift 将栏按钮移到工具栏的左侧

Question

我有一个工具栏位于底部（正确）。问题是按钮（在 UIBarButtonItem 上）位于整个工具栏的中央。

如何将此按钮放在一边，但仍（垂直）居中于图像？ 最好有边距。

所以它看起来像

 --------------
|.    X
|.  label
 --------------

密码是：

    let customButton: UIButton = UIButton(type: .custom)
    customButton.setImage(UIImage(named: "start"), for: .normal)
    customButton.setTitle("Start", for: .normal)
    customButton.titleLabel?.font = UIFont.boldSystemFont(ofSize: 12)
    customButton.setTitleColor(UIColor.white, for: .normal)
    customButton.sizeToFit()
    customButton.centerLabelVerticallyWithPadding(spacing: 5)
    customButton.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(startButtonAction(_:))))
    iconBar.items = [UIBarButtonItem(customView: customButton)]

其中 iconBar - 工具栏定义为：

let iconBar: UIToolbar =
{
    let view = UIToolbar()
    view.translatesAutoresizingMaskIntoConstraints = false
    view.barTintColor = UIColor.black
    return view
}()

我还使用了一个扩展来使 UIButton 居中，然后我可以在它上面添加一个图像（也居中）。这是扩展名：

extension UIButton
{
    func centerLabelVerticallyWithPadding(spacing:CGFloat)
    {
        // update positioning of image and title
        let imageSize = self.imageView!.frame.size
        self.titleEdgeInsets = UIEdgeInsets(top:0,
                                            left:-imageSize.width,
                                            bottom:-(imageSize.height + spacing),
                                            right:0)
        let titleSize = self.titleLabel!.frame.size
        self.imageEdgeInsets = UIEdgeInsets(top:-(titleSize.height + spacing),
                                            left:0,
                                            bottom: 0,
                                            right:-titleSize.width)

        // reset contentInset, so intrinsicContentSize() is still accurate
        let trueContentSize = self.titleLabel!.frame.union(self.imageView!.frame).size
        let oldContentSize = self.intrinsicContentSize
        let heightDelta = trueContentSize.height - oldContentSize.height
        let widthDelta = trueContentSize.width - oldContentSize.width
        self.contentEdgeInsets = UIEdgeInsets(top:heightDelta/2.0,
                                              left:widthDelta/2.0,
                                              bottom:heightDelta/2.0,
                                              right:widthDelta/2.0)
    }
}

Answer 1

您是在寻找 'flexible space bar button item' 还是 'fixed space bar button item'？然后你可以在工具栏的左右两侧添加一点space并定义它的大小。

它将看起来像这样：

let spacer = UIBarButtonItem(barButtonSystemItem: .fixedSpace, target: nil, action: nil)

spacer.width = 10

使用 swift 将栏按钮移到工具栏的左侧

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