我做了一个二维码扫描器应用程序,我已经手动将一些二维码放入解析中进行识别,任何扫描到的二维码都不会被识别。
唯一能区分他们的是他们的(信息),即“餐厅”,“美甲沙龙”等。
我后一种方式,能够记录多少次选择的QRCode已被扫描的整数,然后放在应用程序中的标签。
我可以(.count)用户保存和扫描的所有qrCodes,但似乎不知道如何在解析时将所有“美甲沙龙”放入它们自己的数组中,或者运行一个For循环来匹配我需要的那些。
// The code below will retrieve everything in the "info" column and print it to console
// This prints "Nails Salon" x 5, "Restaurant" x3 and "Coffee Shop" x 7 in the order that they were scanned (Unorganised)
// What block of code could I make to display what PFuser.current currently has in their parse?
// E.g. PFUser has scanned "Nail Salon" 5 Times, "Restaurant" 3 time etc etc
let infoCheck = PFQuery(className: "UserQRCodes")
infoCheck.whereKey("info", contains: "")
infoCheck.findObjectsInBackground { (objects: [PFObject]?, error: Error?) in
if let error = error {
print(error.localizedDescription)
} else if let objects = objects {
print(objects)
}
}
// To retrieve everything the USER has scanned and display it as String on the APP
let query = PFQuery(className: "UserQRCodes")
query.whereKey("userName", equalTo: PFUser.current()!)
query.findObjectsInBackground { (objects: [PFObject]?, error: Error?) in
if let error = error {
//log details of the failure
print(error.localizedDescription)
} else if let objects = objects {
let stampees: Int = objects.count
let totalStampees = String(stampees)
self.stampeesCollectedLabel.text = totalStampees
print(objects.count)
}
}
// Do any additional setup after loading the view.
}
发布于 2019-05-23 22:31:21
您希望过滤扫描数组中的元素。对于每种代码类型,调用类似于
// '$0' is your PFObject. Replace 'name' with whatever `PFObject` property
// represents the object's type
let nailSalons = objects.filter { $0.name == "Nail Salon" }
然后,您可以使用这个经过过滤的数组来获取计数。
请注意,filter { $0... }
语法是
objects.filter { (object) throws -> Bool) in
return object.name == "Nail Salon"
}
如果您的条件比简单的单行表达式更复杂,则需要使用完整版本。请注意,在简短的版本中,return
是隐含的。
https://stackoverflow.com/questions/56276964
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