我制作了一个二维码扫描器应用程序,我手动将一些二维码放入解析中以供其识别,任何扫描的二维码如果我未放入解析中则不会被识别。
唯一区分它们的是他们的(信息),即“餐厅”、“美甲沙龙”等。
我正在寻找一种能够记录所选 QRCode 被扫描次数的整数的方法,然后将其放置在应用程序中的标签上。
我可以(.count)用户保存和扫描的所有 qrCode,但似乎无法弄清楚如何将所有“美甲沙龙”放入自己的解析数组中或运行 For 循环匹配我需要的。
// 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.
}
最佳答案
您想要过滤扫描数组中的元素。对于每种代码类型,调用类似
// '$0' is your PFObject. Replace 'name' with whatever `PFObject` property
// represents the object's type
let nailSalons = objects.filter { $0.name == "Nail Salon" }
然后您可以使用此过滤后的数组来获取计数。
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一行表达式更复杂,则需要使用完整版本。请注意,在简短版本中,return
是隐含的。
关于swift - 是否可以在 Parse 中创建特定对象的数组?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/56276964/