如何更新 DetailView
How to update DetailView
我有一个基于 Master-Detail
模板的 swift 应用程序。 MasterView
table 中的每一行都基于从 nib 接收到的自定义单元格。每个单元格包括 UIlabel
和 UIbutton
。该应用程序的逻辑如下。如果用户点击一行 DetailView
会根据 selected 行显示一些详细信息。行上的按钮不调用 tableView(_, didSelectRowAtIndexPath)
。如果用户点击一行内的按钮,则只有属于 DetailView
的图像应该更改(DetailView
上的其他元素保持不变)但事实并非如此。如果我 select 另一行而不是 select 前一行,则更改后的图像将按预期显示在 DetailView
上。问题是如何通过点击按钮重绘 DetailView
中的图像。
我尝试执行以下操作但没有成功:
class MasterViewCell: UITableViewCell {
weak var detailViewController: DetailViewController?
@IBAction func buttonTap(sender: AnyObject) {
//method to set new image
detailViewController!.setNewImage()
detailViewController!.view.setNeedsDisplay()
}
}
class MasterViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
let nib = UINib(nibName: "itemCell", bundle: nil)
tableView.registerNib(nib, forCellReuseIdentifier: "Cell")
if let split = self.splitViewController {
let controllers = split.viewControllers
self.detailViewController = (controllers[controllers.count-1] as! UINavigationController).topViewController as? DetailViewController
}
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as? MasterViewCell
cell?.detailView = self.detailViewController
return cell!
}
您需要使用处理程序
typealias ButtonHandler = (Cell) -> Void
class Cell: UITableViewCell {
var changeImage: ButtonHandler?
func configureButton(changeImage: ButtonHandler?) {
self.changeImage = changeImage
}
@IBAction func buttonTap(sender: UIButton) {
changeImage?(self)
}
}
并在您的 MasterView 中
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! Cell
cell.configureButton(setNewImage())
return cell
}
private func setNewImage() -> ButtonHandler {
return { [unowned self] cell in
let row = self.tableView.indexPathForCell(cell)?.row //Get the row that was touched
//set the new Image
}
}
来源:
我找到了解决办法。我使用了协议委托机制。现在代码是:
//protocol declaration:
protocol MasterViewCellDelegate: class {
func updateImage(sender: MasterViewCell, detVC: DetailViewController)
}
// cell class
class MasterViewCell: UITableViewCell {
weak var masterViewCellDelegate: MasterViewCellDelegate? // protocol property
weak var masterViewController: MasterViewController? {
didSet {
// set delegate
self.masterViewDelegate = masterViewController!.detailViewController
}
}
@IBAction func buttonTap(sender: AnyObject) {
var detVC: DetailViewController?
if let split = masterViewController!.splitViewController {
let controllers = split.viewControllers
detVC = (controllers[controllers.count - 1] as! UINavigationController).topViewController as? DetailViewController
}
// call delegate
masterViewCellDelegate?.updateImage(self, detVC: detVC)
}
class MasterViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
let nib = UINib(nibName: "itemCell", bundle: nil)
tableView.registerNib(nib, forCellReuseIdentifier: "Cell")
if let split = self.splitViewController {
let controllers = split.viewControllers
self.detailViewController = (controllers[controllers.count-1] as! UINavigationController).topViewController as? DetailViewController
}
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as? MasterViewCell
cell?.masterViewController = self
return cell!
}
// declare detailviewcontroller as delegate
class DetailViewController: UIViewController, MasterViewCellDelegate {
func updateImage(sender: MasterViewCell, detVC: DetailViewController){
detVC.setNewImage()
}
}
很可能这个解决方案过于复杂,但它很有效并且很容易适用于各种目的。
我有一个基于 Master-Detail
模板的 swift 应用程序。 MasterView
table 中的每一行都基于从 nib 接收到的自定义单元格。每个单元格包括 UIlabel
和 UIbutton
。该应用程序的逻辑如下。如果用户点击一行 DetailView
会根据 selected 行显示一些详细信息。行上的按钮不调用 tableView(_, didSelectRowAtIndexPath)
。如果用户点击一行内的按钮,则只有属于 DetailView
的图像应该更改(DetailView
上的其他元素保持不变)但事实并非如此。如果我 select 另一行而不是 select 前一行,则更改后的图像将按预期显示在 DetailView
上。问题是如何通过点击按钮重绘 DetailView
中的图像。
我尝试执行以下操作但没有成功:
class MasterViewCell: UITableViewCell {
weak var detailViewController: DetailViewController?
@IBAction func buttonTap(sender: AnyObject) {
//method to set new image
detailViewController!.setNewImage()
detailViewController!.view.setNeedsDisplay()
}
}
class MasterViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
let nib = UINib(nibName: "itemCell", bundle: nil)
tableView.registerNib(nib, forCellReuseIdentifier: "Cell")
if let split = self.splitViewController {
let controllers = split.viewControllers
self.detailViewController = (controllers[controllers.count-1] as! UINavigationController).topViewController as? DetailViewController
}
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as? MasterViewCell
cell?.detailView = self.detailViewController
return cell!
}
您需要使用处理程序
typealias ButtonHandler = (Cell) -> Void
class Cell: UITableViewCell {
var changeImage: ButtonHandler?
func configureButton(changeImage: ButtonHandler?) {
self.changeImage = changeImage
}
@IBAction func buttonTap(sender: UIButton) {
changeImage?(self)
}
}
并在您的 MasterView 中
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! Cell
cell.configureButton(setNewImage())
return cell
}
private func setNewImage() -> ButtonHandler {
return { [unowned self] cell in
let row = self.tableView.indexPathForCell(cell)?.row //Get the row that was touched
//set the new Image
}
}
来源:
我找到了解决办法。我使用了协议委托机制。现在代码是:
//protocol declaration:
protocol MasterViewCellDelegate: class {
func updateImage(sender: MasterViewCell, detVC: DetailViewController)
}
// cell class
class MasterViewCell: UITableViewCell {
weak var masterViewCellDelegate: MasterViewCellDelegate? // protocol property
weak var masterViewController: MasterViewController? {
didSet {
// set delegate
self.masterViewDelegate = masterViewController!.detailViewController
}
}
@IBAction func buttonTap(sender: AnyObject) {
var detVC: DetailViewController?
if let split = masterViewController!.splitViewController {
let controllers = split.viewControllers
detVC = (controllers[controllers.count - 1] as! UINavigationController).topViewController as? DetailViewController
}
// call delegate
masterViewCellDelegate?.updateImage(self, detVC: detVC)
}
class MasterViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
let nib = UINib(nibName: "itemCell", bundle: nil)
tableView.registerNib(nib, forCellReuseIdentifier: "Cell")
if let split = self.splitViewController {
let controllers = split.viewControllers
self.detailViewController = (controllers[controllers.count-1] as! UINavigationController).topViewController as? DetailViewController
}
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as? MasterViewCell
cell?.masterViewController = self
return cell!
}
// declare detailviewcontroller as delegate
class DetailViewController: UIViewController, MasterViewCellDelegate {
func updateImage(sender: MasterViewCell, detVC: DetailViewController){
detVC.setNewImage()
}
}
很可能这个解决方案过于复杂,但它很有效并且很容易适用于各种目的。