我想使ItemID为全局值,以便我可以在函数外部访问它。我试图在课堂下面定义它,但它不起作用。我还可以在其他函数可访问的函数内创建一个值吗?如何在全局函数内创建一个值
func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [Any]!, from connection: AVCaptureConnection!) {
// Check if the metadataObjects array is not nil and it contains at least one object.
if metadataObjects == nil || metadataObjects.count == 0 {
qrCodeFrameView?.frame = CGRect.zero
messageLabel.text = "No QR/barcode is detected"
return
}
//Get metadata object
let metadataObj = metadataObjects[0] as! AVMetadataMachineReadableCodeObject
if supportedCodeTypes.contains(metadataObj.type) {
//if the found metadata is equal to the QR code metadata then update the status label's text and set the the bounds
let barCodeObject = videoPreviewLayer?.transformedMetadataObject(for: metadataObj)
qrCodeFrameView?.frame = barCodeObject!.bounds
if metadataObj.stringValue != nil {
messageLabel.text = metadataObj.stringValue
//Searches firebase for existing barcode
}
let itemID = metadataObj.stringValue!
let itemToSearchFor = itemID
guard let Description = productDescriptionTextField.text,
let price = priceTextField.text,
let location = productLocationTextField.text
else{
print("Fill basic product information")
return
}
let ref = FIRDatabase.database().reference(fromURL: "/")
// creating an item child node
let values = ["Item Description": Description, "Image": price, "Location": location, "Price": price]
let items = ref.child("Items").child(itemID)
items.updateChildValues(values, withCompletionBlock: { (err, ref) in
if err != nil {
print(err)
return
} })
FIRDatabase.database().reference().child("Items").child(itemToSearchFor).observeSingleEvent(of: .value, with:{(snap) in
print(snap)
})
}}
这是我想打电话给ITEMID
func enterNewProduct() {
guard let Description = self.productDescriptionTextField.text,
let price = self.priceTextField.text,
let location = self.productLocationTextField.text
else{
print("Fill basic product information")
return
}
let ref = FIRDatabase.database().reference(fromURL: "/")
// creating an item child node
let values = ["Item Description": Description, "Image": price, "Location": location, "Price": price ]
let items = ref.child("Items").child(itemID)
items.updateChildValues(values, withCompletionBlock: { (err, ref) in
if err != nil {
print(err)
return
} })
self.dismiss(animated: true, completion: nil)
}
由于某种原因,它不是从以前的功能
什么“没有工作”呢? – Wez
它没有获取itemID。我修改了enterNewItemID函数来打印ItemID,但没有出现。 –