我有一个集合视图。我正在从API获取一些数据，我正在我的集合视图中显示它。每件事情都很好。但是当我加载我的屏幕时 - 首先显示我的屏幕，并且仅在延迟5到6秒之后，填充数据在我的收藏视图中。为了解决这个问题，我做了一些dispatch main thread来快速获取数据。
但有时基于用户手机的数据连接，数据显示较晚。例如，如果用户数据连接速度较慢，则需要大约30秒（假设）才能显示数据我的收藏视图。
所以，我需要的是 - 如何显示活动指示器 - 直到我的数据显示在我的集合视图中。
我知道如何创建一个虚拟Activity Indicator并显示1到30秒。但我必须动态地执行此操作。
这意味着，我需要显示活动指示器，直到数据显示在我的集合视图中。它不应该取决于用户的数据连接速度。
如何实现这一目标？
这是我的代码：
var BTdata = [BTData]()
override func viewDidLoad()
{
super.viewDidLoad()
ListBusinessTypes()
}
// Values from Api for Business Types
func ListBusinessTypes()
{
let token = NSUserDefaults.standardUserDefaults().valueForKey("access_token") as! String
let headers = ["x-access-token": token]
let request = NSMutableURLRequest(URL: NSURL(string: “some url“)!,
cachePolicy: .UseProtocolCachePolicy,
timeoutInterval: 10.0)
request.HTTPMethod = "GET"
request.allHTTPHeaderFields = headers
let session = NSURLSession.sharedSession()
let dataTask = session.dataTaskWithRequest(request, completionHandler: { (data, response, error) -> Void in
if (error != nil)
{
print(error)
let ErrorAlert = UIAlertController(title: "Error", message: "Problem with internet connectivity or server, please try after some time", preferredStyle: UIAlertControllerStyle.Alert)
// add an action (button)
ErrorAlert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: nil))
// show the alert
self.presentViewController(ErrorAlert, animated: true, completion: nil)
}
else
{
if let json = (try? NSJSONSerialization.JSONObjectWithData(data!, options: [])) as? Dictionary<String,AnyObject>
{
let success = json["success"] as? Int
if(success == 1)
{
if let typeValues = json["data"] as? [NSDictionary]
{
dispatch_async(dispatch_get_main_queue(),{
for item in typeValues
{
self.BTdata.append(BTData(json:item))
}
self.collectionView1!.reloadData()
})
}
}
else
{
let message = json["message"] as? String
let ServerAlert = UIAlertController(title: "Error", message: message, preferredStyle: UIAlertControllerStyle.Alert)
// add an action (button)
ServerAlert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: nil))
// show the alert
self.presentViewController(ServerAlert, animated: true, completion: nil)
}
}
}
})
dataTask.resume()
}
答案 0 :(得分：2)
我对您的代码进行了一些更改，下面是
将这些用作类变量
var actView: UIView = UIView()
var loadingView: UIView = UIView()
var activityIndicator: UIActivityIndicatorView = UIActivityIndicatorView()
var titleLabel: UILabel = UILabel()
并在您的服务呼叫功能
showActivity(self.view, myTitle: "Loading...")
let dataTask = session.dataTaskWithRequest(request) {(data, response, error) in
dispatch_async(dispatch_get_main_queue(), {
if response != nil {
if error != nil {
print(error)
removeActivity(self.view)
let ErrorAlert = UIAlertController(title: "Error", message: "Problem with internet connectivity or server, please try after some time", preferredStyle: UIAlertControllerStyle.Alert)
// add an action (button)
ErrorAlert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: nil))
// show the alert
self.presentViewController(ErrorAlert, animated: true, completion: nil)
}else {
if let json = (try? NSJSONSerialization.JSONObjectWithData(data!, options: [])) as? Dictionary<String,AnyObject> {
let success = json["success"] as? Int
if(success == 1) {
if let typeValues = json["data"] as? [NSDictionary] {
dispatch_async(dispatch_get_main_queue(),{
for item in typeValues {
self.BTdata.append(BTData(json:item))
}
self.collectionView1!.reloadData()
removeActivity(self.view)
})
} else {
removeActivity(self.view)
}
} else {
removeActivity(self.view)
let message = json["message"] as? String
let ServerAlert = UIAlertController(title: "Error", message: message, preferredStyle: UIAlertControllerStyle.Alert)
// add an action (button)
ServerAlert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: nil))
// show the alert
self.presentViewController(ServerAlert, animated: true, completion: nil)
}
} else {
removeActivity(self.view)
}
}
}
})
}
dataTask.resume()
开始制作动画的功能
func showActivity(myView: UIView, myTitle: String) {
myView.userInteractionEnabled = false
myView.window?.userInteractionEnabled = false
myView.endEditing(true)
actView.frame = CGRectMake(0, 0, myView.frame.width, myView.frame.height)
actView.center = myView.center
actView.backgroundColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.3)
loadingView.frame = CGRectMake(0, 0, 80, 80)
loadingView.center = myView.center
loadingView.backgroundColor = THEME_COLOUR
loadingView.clipsToBounds = true
loadingView.layer.cornerRadius = 15
activityIndicator.frame = CGRectMake(0.0, 0.0, 40.0, 40.0);
activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.WhiteLarge
activityIndicator.center = CGPointMake(loadingView.frame.size.width / 2, loadingView.frame.size.height / 2);
titleLabel.frame = CGRectMake(5, loadingView.frame.height-20, loadingView.frame.width-10, 20)
titleLabel.textColor = UIColor.whiteColor()
titleLabel.adjustsFontSizeToFitWidth = true
titleLabel.textAlignment = NSTextAlignment.Center
titleLabel.text = myTitle
titleLabel.font = IH_DELEGATE.BoldAppFontOfSize(10)
loadingView.addSubview(activityIndicator)
actView.addSubview(loadingView)
loadingView.addSubview(titleLabel)
myView.addSubview(actView)
activityIndicator.startAnimating()
}
停止动画的功能
func removeActivity(myView: UIView) {
myView.userInteractionEnabled = true
myView.window?.userInteractionEnabled = true
activityIndicator.stopAnimating()
actView.removeFromSuperview()
}
修改 忘了提到
let THEME_COLOUR = UIColor (red:0.188, green:0.682, blue:0.886, alpha:1)
答案 1 :(得分：1)
要设置指标，请创建2种启动和停止指示的方法。如下所示，
首先创建IBOutlet
var activityIndicator:UIActivityIndicatorView = UIActivityIndicatorView()
创建开始方法：
func startIndicator()
{
//creating view to background while displaying indicator
let container: UIView = UIView()
container.frame = self.view.frame
container.center = self.view.center
container.backgroundColor = CONTAINER_VIEW_BACKGROUND_COLOR
//creating view to display lable and indicator
let loadingView: UIView = UIView()
loadingView.frame = CGRectMake(0, 0, 118, 80)
loadingView.center = self.view.center
loadingView.backgroundColor = LOADING_VIEW_BACKGROUND_COLOR
loadingView.clipsToBounds = true
loadingView.layer.cornerRadius = 10
//Preparing activity indicator to load
self.activityIndicator = UIActivityIndicatorView()
self.activityIndicator.frame = CGRectMake(40, 12, 40, 40)
self.activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.WhiteLarge
loadingView.addSubview(activityIndicator)
//creating label to display message
let label = UILabel(frame: CGRectMake(5, 55,120,20))
label.text = "Loading..."
label.textColor = UIColor.whiteColor()
label.bounds = CGRectMake(0, 0, loadingView.frame.size.width / 2, loadingView.frame.size.height / 2)
label.font = UIFont.systemFontOfSize(12)
loadingView.addSubview(label)
container.addSubview(loadingView)
self.view.addSubview(container)
self.activityIndicator.startAnimating()
}
创建停止方法：
func stopIndicator()
{
UIApplication.sharedApplication().endIgnoringInteractionEvents()
self.activityIndicator.stopAnimating()
((self.activityIndicator.superview as UIView!).superview as UIView!).removeFromSuperview()
}
然后在viewDidload中调用startIndicator，在ListBusinessType方法之上。 当你从api获得成功和失败回应时停止它。 这会对你有所帮助。 ：）
注意：根据您的应用主题更改颜色。