[英]iOS Scaling Constraints for Different Screen Sizes
這是我的第一個iOS應用,正在使用Swift。 我正在遵循CodeWithChris.com上的教程。
用戶將點擊一系列圖標來確定他們所擁有的設備型號。 到目前為止,我已經使用了一些約束條件來將圖標正確放置在iPhone 6顯示屏上。 當使用iPhone 5S / 5c / 5或4S / 4顯示屏尺寸時,圖標和文本仍以iPhone 6的完整尺寸呈現,並且它們離開屏幕。
這是我構建布局的過程:
我使用了一堆約束來放置UIViews和UIImageViews。 如何根據設備的屏幕尺寸使這些約束動態化?
iPhone 6,藍色為contentView,紅色為UIViews
iPhone 6
iPhone 5 / 5S / 5c
iPhone 4S / 4
這是我添加設備UIView並應用約束的地方:
// Loop through the array of DeviceTypes to add each to the UIView
for index in 0...deviceTypes.count-1 {
// Grab the current device
var thisDevice:DeviceType = deviceTypes[index]
// Add to the view!
contentView.addSubview(thisDevice)
thisDevice.setTranslatesAutoresizingMaskIntoConstraints(false)
// How tall is the Device UIView
var heightConstraint:NSLayoutConstraint = NSLayoutConstraint(item: thisDevice, attribute: NSLayoutAttribute.Height, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1, constant: 200)
// How wide is the device UIView
var widthConstraint:NSLayoutConstraint = NSLayoutConstraint(item: thisDevice, attribute: NSLayoutAttribute.Width, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1, constant: 130)
// How far is the bottom of the UIView from the top of the contentView
var bottomMarginConstraint:NSLayoutConstraint = NSLayoutConstraint(item: thisDevice, attribute: NSLayoutAttribute.Top, relatedBy: NSLayoutRelation.Equal, toItem: contentView, attribute: NSLayoutAttribute.Top, multiplier: 1, constant: 100)
// Add thisDevice's UIView constraints
thisDevice.addConstraints([heightConstraint, widthConstraint])
contentView.addConstraint(bottomMarginConstraint)
thisDevice.backgroundColor = UIColor.redColor()
// set UIView position constraints based on place in row
if (index > 0) {
// device is second or further in row
var deviceOnTheLeft = deviceTypes[index-1]
var leftMarginConstraint:NSLayoutConstraint = NSLayoutConstraint(item: thisDevice, attribute: NSLayoutAttribute.Left, relatedBy: NSLayoutRelation.Equal, toItem: deviceOnTheLeft, attribute: NSLayoutAttribute.Right, multiplier: 1, constant: 10)
contentView.addConstraint(leftMarginConstraint)
}
else {
// device is first in row
var leftMarginConstraint:NSLayoutConstraint = NSLayoutConstraint(item: thisDevice, attribute: NSLayoutAttribute.Left, relatedBy: NSLayoutRelation.Equal, toItem: contentView, attribute: NSLayoutAttribute.Left, multiplier: 1, constant: 0)
// Add constraint
contentView.addConstraint(leftMarginConstraint)
}
這是我應用於圖標圖像的約束:
func addDeviceImages() {
// Set right image based on deviceType name
self.frontImageView.image = UIImage(named: self.Name!)
// Set translates autoresizing mask to fault
self.frontImageView.setTranslatesAutoresizingMaskIntoConstraints(false)
// Add the imageview to the view
self.addSubview(self.frontImageView)
if (self.Name == "Windows") {
self.addImageSizeConstraints(90, height: 160)
}
else if (self.Name == "iPad"){
self.addImageSizeConstraints(120, height: 180)
}
else if (self.Name == "iPhone"){
self.addImageSizeConstraints(85, height: 175)
}
else if (self.Name == "Android"){
self.addImageSizeConstraints(95, height: 185)
}
}
func addImageSizeConstraints(width: CGFloat, height: CGFloat) {
// Set the size constraints for the imageview based on the values passed in
var heightConstraint:NSLayoutConstraint = NSLayoutConstraint(item: self.frontImageView, attribute: NSLayoutAttribute.Height, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1, constant: height)
var widthConstraint:NSLayoutConstraint = NSLayoutConstraint(item: self.frontImageView, attribute: NSLayoutAttribute.Width, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1, constant: width)
self.frontImageView.addConstraints([heightConstraint, widthConstraint])
// Set the position of the imageview in the UIView
var verticalConstraint:NSLayoutConstraint = NSLayoutConstraint( item: self.frontImageView, attribute: NSLayoutAttribute.Bottom, relatedBy: NSLayoutRelation.Equal, toItem: self, attribute: NSLayoutAttribute.Bottom, multiplier: 1, constant: -25)
var horizontalConstraint:NSLayoutConstraint = NSLayoutConstraint( item: self.frontImageView, attribute: NSLayoutAttribute.Left, relatedBy: NSLayoutRelation.Equal, toItem: self, attribute: NSLayoutAttribute.Left, multiplier: 1, constant: 5)
self.addConstraints([horizontalConstraint,verticalConstraint])
}
您使用了錯誤的約束類型。 您的寬度限制是絕對的-您要設置一個固定的constant
。 取而代之的是,使constant
0,而寬度取決於高度,並使用multiplier
的值正確確定縱橫比。 這樣,隨着高度的變化,寬度將變化以匹配。 對圖像之間的分隔進行相同的處理-使分隔取決於乘數,取決於超級視圖的寬度。
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