Question

我以这种方式以编程方式创建了按钮

func CreateButtonWithIndex(index:Int) {
    let widthButton = 120
    let heightButton = 80
    let line = (index / 3)
    let column = index % 3
    let newButton = UIButton.buttonWithType(UIButtonType.System) as UIButton
    newButton.frame = CGRect(x:line*widthButton+95, y:column*heightButton+15, width:widthButton, height:heightButton)

    self.view.addSubview(newButton)
}

现在尝试以这种方式为此按钮放置NSLayoutConstraint

func CreateButtonWithIndex(index:Int) {

    let widthButton = 120
    let heightButton = 80
    let line = (index / 3)
    let column = index % 3
    let newButton = UIButton.buttonWithType(UIButtonType.System) as UIButton
    newButton.setTranslatesAutoresizingMaskIntoConstraints(false)

    self.view.addSubview(newButton)

    let constraint1 = NSLayoutConstraint(item: newButton, attribute: .CenterX, relatedBy: .Equal, toItem: view, attribute: .CenterX, multiplier: 1, constant: 1)

    let constraint2 = NSLayoutConstraint(item: newButton, attribute: .CenterY, relatedBy: .Equal, toItem: view, attribute: .CenterY, multiplier: 1, constant: 10)

    view.addConstraints([constraint1,constraint2])

}

但显然我只是在同一个位置创建了各种按钮。我试过例如

   let constraint1 = NSLayoutConstraint(item: newButton, attribute: .CenterX, relatedBy: .Equal, toItem: view, attribute: .CenterX, multiplier: 1, constant: line)

但不要去!!!

如何使用NSLayoutConstraint放置行和列？

Answer 1

你走在正确的轨道上！问题是你的计算没有在x位置给出足够大的差异。你在说：

let constraint1 = NSLayoutConstraint(
    item: newButton, attribute: .CenterX, relatedBy: .Equal, 
    toItem: view, attribute: .CenterX, multiplier: 1, constant: line)

但是line是什么？

let line = (index / 3)

好吧，如果index为0，则为1，然后为2，line每次都为0。如果您希望这些按钮位于不同的位置，则需要多更大的差异！

（显然，您也应该向CGFloat声明或投射line。）

使用AutoLayout快速更改按钮位置

1 个答案: