这就是我设法做到的，有最好的方法吗？（当您检索文档时，您会在[“field”：值]

let clientDocRef = db.collection("co1").document("doc1")
            clientDocRef.getDocument { (document, error) in
                if let document = document, document.exists {
                    let dataDescription = document.data().map(String.init(describing:)) ?? "nil"
                    print("Document data: \(dataDescription)")
                    if dataDescription.contains("\"Field1\"") {
                        print ("field exists")
                    } else {
                            print("field doesnt exist") }
                    } else {
                    print("Document does not exist")
                }
            }

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