swift - 更改 UISegmentedControl 后如何重新加载 UIViewController
问题描述
我有一个带有 UISegmentedControl 的 viewController 可以在 2 个内容之间切换(按部门或按配方)。当我切换 segmentedControl(它将执行 changeColor 函数)时,我想更改与选择的段相对应的内容。每个段中的内容是几个 UILabel 然后像 view.addSubview(label) 一样添加它们。但是,我当前的代码所做的是将它们相互重叠。
class GroceryViewController: UIViewController {
var customSC = UISegmentedControl()
override func viewDidLoad() {
super.viewDidLoad()
setupSegmentedControl()
contentByDepartment()
}
func setupSegmentedControl() {
let items = ["BY DEPARTMENT", "BY RECIPE"]
customSC = UISegmentedControl(items: items)
customSC.selectedSegmentIndex = 0
let frame = UIScreen.main.bounds
customSC.frame = CGRect(x:frame.minX + 15, y:frame.minY + 100,
width:frame.width - 30, height:frame.height * 0.04)
customSC.layer.cornerRadius = 20
customSC.backgroundColor = UIColor(hexString: "#F7F7F7")
customSC.setTitleTextAttributes([NSAttributedString.Key.foregroundColor: UIColor(hexString: "#FC6A03")], for: UIControl.State.selected)
customSC.addTarget(self, action: #selector(changeColor), for: .valueChanged)
view.addSubview(customSC)
}
@objc func changeColor(_ sender: UISegmentedControl) {
switch sender.selectedSegmentIndex {
case 0:
contentByDepartment() // contents are several UILabel adding to view as SubView
case 1:
contentByRecipe() // contents are several UILabel adding to view as SubView
default:
break
}
}
}
我已经搜索了解决方案,主要是“UITableView 中的 reloadData()”,我没有。所以我不知道如何在不打扰 UIView 或 UITableView 的情况下重新加载这个 viewController。
问题是:是否可以从某个功能单独重新加载 viewController,以便在显示所选内容之前清除以前的内容以及如何这样做?
编辑: contentByDepartment 和 contentByRecipe 的代码
func contentByDepartment() {
let recipeHeader = UILabel(frame: CGRect(x:50, y:180, width: 200, height: 20))
recipeHeader.setActivityDescription(label: "Coffee and Tea")
recipeHeader.textColor = UIColor(hexString: "#FC6A03")
recipeHeader.font = UIFont.systemFont(ofSize: 20)
let ingredient1Name = UILabel(frame: CGRect(x:70,y:210,width:200,height:20))
ingredient1Name.setActivityDescription(label: "Green tea leaves")
ingredient1Name.font = UIFont.systemFont(ofSize: 16)
let ingredient1Amount = UILabel(frame: CGRect(x:72,y:230,width:200,height:20))
ingredient1Amount.setActivityDescription(label: "1 tablespoons")
ingredient1Amount.font = UIFont.systemFont(ofSize: 12)
let ingredient2Name = UILabel(frame: CGRect(x:70,y:260,width:200,height:20))
ingredient2Name.setActivityDescription(label: "Coffee powder")
ingredient2Name.font = UIFont.systemFont(ofSize: 16)
let ingredient2Amount = UILabel(frame: CGRect(x:72,y:280,width:200,height:20))
ingredient2Amount.setActivityDescription(label: "3 tablespoons")
ingredient2Amount.font = UIFont.systemFont(ofSize: 12)
view.addSubview(recipeHeader)
view.addSubview(ingredient1Name)
view.addSubview(ingredient1Amount)
view.layer.addSublayer(drawLine(x1:70, y1:255, x2:350, y2:255, lineWidth:0.3))
view.addSubview(ingredient2Name)
view.addSubview(ingredient2Amount)
view.layer.addSublayer(drawLine(x1:0, y1:310, x2:420, y2:310, lineWidth:0.5))
}
func contentByRecipe() {
let recipeHeader = UILabel(frame: CGRect(x:50, y:180, width: 200, height: 20))
recipeHeader.setActivityDescription(label: "Cha-yen")
recipeHeader.textColor = UIColor(hexString: "#FC6A03")
recipeHeader.font = UIFont.systemFont(ofSize: 20)
let ingredient1Name = UILabel(frame: CGRect(x:70,y:210,width:200,height:20))
ingredient1Name.setActivityDescription(label: "Vanilla extract")
ingredient1Name.font = UIFont.systemFont(ofSize: 16)
let ingredient1Amount = UILabel(frame: CGRect(x:72,y:230,width:200,height:20))
ingredient1Amount.setActivityDescription(label: "1 tablespoons")
ingredient1Amount.font = UIFont.systemFont(ofSize: 12)
let ingredient2Name = UILabel(frame: CGRect(x:70,y:260,width:200,height:20))
ingredient2Name.setActivityDescription(label: "Sugar")
ingredient2Name.font = UIFont.systemFont(ofSize: 16)
let ingredient2Amount = UILabel(frame: CGRect(x:72,y:280,width:200,height:20))
ingredient2Amount.setActivityDescription(label: "3 tablespoons")
ingredient2Amount.font = UIFont.systemFont(ofSize: 12)
view.addSubview(recipeHeader)
view.addSubview(ingredient1Name)
view.addSubview(ingredient1Amount)
view.layer.addSublayer(drawLine(x1:70, y1:255, x2:350, y2:255, lineWidth:0.3))
view.addSubview(ingredient2Name)
view.addSubview(ingredient2Amount)
view.layer.addSublayer(drawLine(x1:0, y1:310, x2:420, y2:310, lineWidth:0.5))
}
解决方案
您应该学习将相关视图组合在一起。现在,您将所有视图添加为view
. 这是非常杂乱无章的,并导致您进入当前情况 - 无法有效地显示/隐藏某些视图。
组织视图的一种方法是将“按部门”视图添加到一个大视图UIView
中,并将所有“按配方”视图添加到另一个大视图UIView
中。
var byDepartmentContainerView: UIView!
func setUpContentByDepartment() {
let recipeHeader = UILabel(frame: ...)
recipeHeader.setActivityDescription(label: "Coffee and Tea")
recipeHeader.textColor = UIColor(hexString: "#FC6A03")
recipeHeader.font = UIFont.systemFont(ofSize: 20)
let ingredient1Name = UILabel(frame: ...)
ingredient1Name.setActivityDescription(label: "Green tea leaves")
ingredient1Name.font = UIFont.systemFont(ofSize: 16)
let ingredient1Amount = UILabel(frame: ...)
ingredient1Amount.setActivityDescription(label: "1 tablespoons")
ingredient1Amount.font = UIFont.systemFont(ofSize: 12)
let ingredient2Name = UILabel(frame: ...)
ingredient2Name.setActivityDescription(label: "Coffee powder")
ingredient2Name.font = UIFont.systemFont(ofSize: 16)
let ingredient2Amount = UILabel(frame: ...)
ingredient2Amount.setActivityDescription(label: "3 tablespoons")
ingredient2Amount.font = UIFont.systemFont(ofSize: 12)
byDepartmentContainerView = UIView(frame: ...)
byDepartmentContainerView.addSubview(recipeHeader)
byDepartmentContainerView.addSubview(ingredient1Name)
byDepartmentContainerView.addSubview(ingredient1Amount)
byDepartmentContainerView.addSubview(ingredient2Name)
byDepartmentContainerView.addSubview(ingredient2Amount)
}
var byRecipeContainerView: UIView!
func setUpContentByRecipe() {
let recipeHeader = UILabel(frame: CGRect(x:50, y:180, width: 200, height: 20))
recipeHeader.setActivityDescription(label: "Cha-yen")
recipeHeader.textColor = UIColor(hexString: "#FC6A03")
recipeHeader.font = UIFont.systemFont(ofSize: 20)
let ingredient1Name = UILabel(frame: CGRect(x:70,y:210,width:200,height:20))
ingredient1Name.setActivityDescription(label: "Vanilla extract")
ingredient1Name.font = UIFont.systemFont(ofSize: 16)
let ingredient1Amount = UILabel(frame: CGRect(x:72,y:230,width:200,height:20))
ingredient1Amount.setActivityDescription(label: "1 tablespoons")
ingredient1Amount.font = UIFont.systemFont(ofSize: 12)
let ingredient2Name = UILabel(frame: CGRect(x:70,y:260,width:200,height:20))
ingredient2Name.setActivityDescription(label: "Sugar")
ingredient2Name.font = UIFont.systemFont(ofSize: 16)
let ingredient2Amount = UILabel(frame: CGRect(x:72,y:280,width:200,height:20))
ingredient2Amount.setActivityDescription(label: "3 tablespoons")
ingredient2Amount.font = UIFont.systemFont(ofSize: 12)
byRecipeContainerView = UIView(frame: ...)
byRecipeContainerView.addSubview(recipeHeader)
byRecipeContainerView.addSubview(ingredient1Name)
byRecipeContainerView.addSubview(ingredient1Amount)
byRecipeContainerView.addSubview(ingredient2Name)
byRecipeContainerView.addSubview(ingredient2Amount)
}
请注意,我省略了视图的框架。请给容器视图一个足够大的框架以包含其所有子视图,并调整子视图的框架,使它们相对于容器视图的坐标系。
此外,您似乎在两种方法中都绘制了相同的线条,因此可以一次完成,再也不会。
func drawLines() {
view.layer.addSublayer(drawLine(x1:0, y1:310, x2:420, y2:310, lineWidth:0.5))
view.layer.addSublayer(drawLine(x1:70, y1:255, x2:350, y2:255, lineWidth:0.3))
}
在viewDidLoad
中,您可以调用所有三种方法:
setUpContentByDepartment()
setUpContentByRecipe()
drawLines()
view.addSubview(byDepartmentContainerView)
view.addSubview(byRecipeContainerView)
byRecipeContainerView.isHidden = true
现在您可以执行以下操作:
switch sender.selectedSegmentIndex {
case 0:
byRecipeContainerView.isHidden = true
byDepartmentContainerView.isHidden = false
case 1:
byRecipeContainerView.isHidden = false
byDepartmentContainerView.isHidden = true
default:
break
}
PS硬编码视图的帧是一个非常糟糕的主意。它不能本地化,不能适应不同的设备等等。请了解Autolayout Constraints。
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