我的应用使用手势向左或向右滑动图片(我正在学习教程)。代码过去工作正常，但我认为在将 Xcode 更新到 7(从版本 6)后它坏了。当我滑动图片时，应用程序崩溃并显示以下消息:
由于未捕获的异常“NSInvalidArgumentException”而终止应用程序，原因:“-[...... wasDragged:]:无法识别的选择器发送到实例
这似乎是 Swift 中的一个常见错误，有许多不同的原因可以解释为什么会发生这种情况。我确认我实际上是在 viewDidLoad 之外调用该函数，所以我不确定哪里出了问题:
override func viewDidLoad() {
super.viewDidLoad()
//start geolocation services
PFGeoPoint.geoPointForCurrentLocationInBackground { (geopoint, error) -> Void in
if let geopoint = geopoint {
if let user = PFUser.currentUser() {
// save the latest location for the user right away... this can continue
// asynchronously in the background, we don't really care how long it takes.
// You may still want to check for errors here, or even use the saveEventually method
user["location"] = geopoint
user.saveInBackgroundWithBlock(nil);
let query:PFQuery=PFUser.query()!
// check that we have a location for the user
query.whereKeyExists("location")
query.whereKey("location", nearGeoPoint: geopoint)
// filtering for interests directly in the query. This way we don't need to retrieve all data and
// then loop over it
query.whereKey("gender", equalTo: user["interestedIn"]!)
// exclude the current user
query.whereKey("user", notEqualTo: user)
query.limit = 10
query.findObjectsInBackgroundWithBlock({ (users, error) -> Void in
// TODO: I'm just printing it here but you should handle the error in a smart way
print(error)
print(users);
var accepted = [String]()
if let userAccepted = user["accepted"] as? [String] {
accepted = userAccepted
}
var rejected = [String]()
if let userRejected = user["rejected"] as? [String] {
rejected = userRejected
}
if let users = users as? [PFUser]{
for user in users {
// TODO: You should move this as a query condition so that you always know you get
// 10 users or however many you need
if !accepted.contains(user.objectId!) && !rejected.contains(user.objectId!){
self.usernames.append(user.username!)
self.users.append(user )
if let data = user["image"] as? NSData {
self.userImages.append(data)
}
}
}
}
let userImage: UIImageView = UIImageView(frame: CGRectMake(0, 0, self.view.frame.width, self.view.frame.height))
//println("images:")
//println(userImage)
//println(self.userImages)
if ( self.userImages.count > 0 ) {
userImage.image = UIImage(data: self.userImages[0])
userImage.contentMode = UIViewContentMode.ScaleAspectFit
self.view.addSubview(userImage)
}
let gesture = UIPanGestureRecognizer(target: self, action: "wasDragged:")
userImage.addGestureRecognizer(gesture)
userImage.userInteractionEnabled = true
self.users = (users as? [PFUser])!
})
}
}
}
}
func wasDragged(gesture: UIPanGestureRecognizer) throws {
let translation = gesture.translationInView(self.view)
let label = gesture.view!
xFromCenter += translation.x
let scale = min(100 / abs(xFromCenter), 1)
label.center = CGPoint(x: label.center.x + translation.x, y: label.center.y + translation.y)
gesture.setTranslation(CGPointZero, inView: self.view)
let rotation:CGAffineTransform = CGAffineTransformMakeRotation(xFromCenter / 200)
let stretch:CGAffineTransform = CGAffineTransformScale(rotation, scale, scale)
label.transform = stretch
if label.center.x < 100 {
print("Not Chosen")
PFUser.currentUser()!.addUniqueObject(self.users[self.currentUser], forKey: "rejected")
try PFUser.currentUser()!.save()
self.currentUser++
} else if label.center.x > self.view.bounds.width - 100 {
print("Chosen")
if !isSaving {
isSaving = true
PFUser.currentUser()!.addUniqueObject(self.users[self.currentUser], forKey: "accepted")
PFUser.currentUser()!.saveInBackgroundWithBlock{
(success: Bool, error: NSError?) -> Void in
self.isSaving = false
if success {
self.performSegueWithIdentifier("startGame", sender: "user")
} else {
if let realError = error {
print(realError)
}
else {
print("Filled without error")
}
}
}
}
//self.currentUser++
return
}
if gesture.state == UIGestureRecognizerState.Ended {
label.removeFromSuperview()
if self.currentUser < self.userImages.count {
let userImage: UIImageView = UIImageView(frame: CGRectMake(0, 0, self.view.frame.width, self.view.frame.height))
userImage.image = UIImage(data: self.userImages[self.currentUser])
userImage.contentMode = UIViewContentMode.ScaleAspectFit
self.view.addSubview(userImage)
let gesture = UIPanGestureRecognizer(target: self, action: "wasDragged:")
userImage.addGestureRecognizer(gesture)
userImage.userInteractionEnabled = true
xFromCenter = 0
} else {
print("No more users")
}
}
}
如有任何帮助，我们将不胜感激。
谢谢!
最佳答案
您必须删除 throws，因为这会更改方法签名并且 objc 无论如何都不会处理它。
关于ios - 无法识别的选择器发送到 Swift 中的实例？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34057276/