如何从用 Swift 编写的 Flutter 平台特定代码启动 ViewController？
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【中文标题】如何从用 Swift 编写的 Flutter 平台特定代码启动 ViewController？【英文标题】：How to launch a ViewController from Flutter Platform Specific code written in Swift? 【发布时间】：2019-05-08 05:31:19 【问题描述】：我正在为 Paytm 创建一个插件，并为 android 和 ios 编写特定于平台的代码。
Paytm 是印度的支付网关服务，非常易于配置和集成到应用程序中。它需要一些配置，最后一步是启动支付交易，它在内部打开自己的 Android Activity 和 iOS 平台的 ViewController。
我测试了插件的 Android 部分。它工作正常。
但我不知道如何在 iOS 中触发 viewController。我正在使用 swift 进行 iOS 编码部分。
func beginPayment()
serv = serv.createProductionEnvironment()
let type :ServerType = .eServerTypeProduction
let order = PGOrder(orderID: "", customerID: "", amount: "", eMail: "", mobile: "")
order.params = [
"MID": "rxazcv89315285244163",
"ORDER_ID": "order1",
"CUST_ID": "cust123",
"MOBILE_NO": "7777777777",
"EMAIL": "username@emailprovider.com",
"CHANNEL_ID": "WAP",
"WEBSITE": "WEBSTAGING",
"TXN_AMOUNT": "100.12",
"INDUSTRY_TYPE_ID": "Retail",
"CHECKSUMHASH": "oCDBVF+hvVb68JvzbKI40TOtcxlNjMdixi9FnRSh80Ub7XfjvgNr9NrfrOCPLmt65UhStCkrDnlYkclz1qE0uBMOrmuKLGlybuErulbLYSQ=",
"CALLBACK_URL": "https://securegw-stage.paytm.in/theia/paytmCallback?ORDER_ID=order1"
]
self.txnController = self.txnController.initTransaction(for: order) as?PGTransactionViewController
self.txnController.title = "Paytm Payments" self.txnController.setLoggingEnabled(true)
if(type != ServerType.eServerTypeNone)
self.txnController.serverType = type;
else return
self.txnController.merchant = PGMerchantConfiguration.defaultConfiguration()
self.txnController.delegate = self
self.navigationController?.pushViewController(self.txnController, animated: true)
这是在 PayTM iOS SDK 文档页面中编写的关于如何触发 Paytm 交易控制器的演示。
这是我为实现上述过程而编写的代码。
import Flutter
import PaymentSDK
import UIKit
/*
A delegate interface that exposes all of the PayTM Payment Gateway functionality for other plugins to use.
The below [Delegate] implementation should be used by any clients unless they need to
override some of these functions, such as for testing.
*/
protocol IDelegate
// Initializes this delegate so that it can perform transaction operation
func initializePaytmService(result: @escaping FlutterResult, buildVariant: String?)
// Returns the PayTM transaction status without displaying any user interface.
func startPaymentTransaction(result: @escaping FlutterResult, checkSumRequestObject: Dictionary<String, String>?)
/*
Delegate class will have the code for making PayTM Transactions.
*/
class FlutterPaytmPluginDelegate : IDelegate, PGTransactionDelegate
private let flutterRegistrar: FlutterPluginRegistrar
private var viewController: UIViewController
private var serverType: ServerType?
private var pendingOperation: PendingOperation?
private var paytmTransactionController: PGTransactionViewController?
let release = "BuildVariant.release"
let debug = "BuildVariant.debug"
//Method Constants
let methodInitPaytmService = "initialize_paytm_service"
let methodStartPaymentTransaction = "start_payment_transaction"
//PayTM Success Response Constants
let paytmStatus = "STATUS"
let paytmChecksumHash = "CHECKSUMHASH"
let paytmBankName = "BANKNAME"
let paytmOrderId = "ORDERID"
let paytmTransactionAmount = "TXNAMOUNT"
let paytmTransactionDate = "TXNDATE"
let paytmMerchantId = "MID"
let paytmTransactionId = "TXNID"
let paytmResponseCode = "RESPCODE"
let paytmPaymentMode = "PAYMENTMODE"
let paytmBankTransactionId = "BANKTXNID"
let paytmCurrency = "CURRENCY"
let paytmGatewayName = "GATEWAYNAME"
let paytmResponseMessage = "RESPMSG"
//Error Constants
let errorReasonBuildVariantNotPassed = "build_variant_not_passed"
let errorReasonChecksumObjectNotPassed = "checksum_request_object_not_passed"
// These error codes must match with ones declared on iOS and Dart sides.
let errorReasonPaytmTransactionResponseNull = "paytm_transaction_response_null"
let errorReasonPaytmTransactionCancelled = "paytm_transaction_cancelled"
let errorReasonPaytmMissingParameters = "paytm_missing_parameters"
init(registrar: FlutterPluginRegistrar, viewController: UIViewController)
self.flutterRegistrar = registrar
self.viewController = viewController
/*
Initializes this delegate so that it is ready to perform other operations. The Dart code
guarantees that this will be called and completed before any other methods are invoked.
*/
func initializePaytmService(result: @escaping FlutterResult, buildVariant: String?)
if buildVariant?.isEmpty ?? true
result(FlutterError(code: errorReasonBuildVariantNotPassed, message: "Need a build variant", details: nil))
else
serverType = buildVariant == release ? .eServerTypeProduction : .eServerTypeStaging
result(nil)
func startPaymentTransaction(result: @escaping FlutterResult, checkSumRequestObject: Dictionary<String, String>?)
if checkSumRequestObject?.isEmpty ?? true
result(FlutterError(code: errorReasonChecksumObjectNotPassed, message: "Need a build variant", details: nil))
else
checkAndSetPendingOperation(method: methodStartPaymentTransaction, result: result)
let order = PGOrder(orderID: "", customerID: "", amount: "", eMail: "", mobile: "")
order.params = checkSumRequestObject!
self.paytmTransactionController = paytmTransactionController?.initTransaction(for: order) as? PGTransactionViewController ?? PGTransactionViewController()
self.paytmTransactionController?.title = "Paytm Payments"
if(serverType != .eServerTypeNone)
self.paytmTransactionController?.serverType = serverType;
else
return
self.paytmTransactionController?.setLoggingEnabled(serverType == .eServerTypeStaging)
self.paytmTransactionController?.merchant = PGMerchantConfiguration.defaultConfiguration()
self.paytmTransactionController?.delegate = self
UIApplication.shared.delegate?.window??.rootViewController?.present(paytmTransactionController, animated: true, completion: nil)
private func checkAndSetPendingOperation(method: String, result: @escaping FlutterResult)
if (pendingOperation != nil)
return;
// throw IllegalStateException("Concurrent operations detected: " + pendingOperation!!.method + ", " + method)
pendingOperation = PendingOperation(method: method, result: result)
private func finishWithSuccess(data: Dictionary<String, String>?)
pendingOperation!.result(data)
pendingOperation = nil
paytmTransactionController = nil
private func finishWithError(errorCode: String, errorMessage: String)
pendingOperation!.result(FlutterError(code: errorCode, message: errorMessage, details: nil))
pendingOperation = nil
/*
PayTM Transaction Delegates
*/
func didFinishedResponse(_ controller: PGTransactionViewController, response responseString: String)
var paytmSuccessResponse = Dictionary<String, String>()
if let data = responseString.data(using: String.Encoding.utf8)
do
if let jsonresponse = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String:String] , jsonresponse.count > 0
paytmSuccessResponse[paytmStatus] = jsonresponse[paytmStatus] ?? ""
paytmSuccessResponse[paytmChecksumHash] = jsonresponse[paytmChecksumHash] ?? ""
paytmSuccessResponse[paytmBankName] = jsonresponse[paytmBankName] ?? ""
paytmSuccessResponse[paytmOrderId] = jsonresponse[paytmOrderId] ?? ""
paytmSuccessResponse[paytmTransactionAmount] = jsonresponse[paytmTransactionAmount] ?? ""
paytmSuccessResponse[paytmTransactionDate] = jsonresponse[paytmTransactionDate] ?? ""
paytmSuccessResponse[paytmTransactionId] = jsonresponse[paytmTransactionId] ?? ""
paytmSuccessResponse[paytmMerchantId] = jsonresponse[paytmMerchantId] ?? ""
paytmSuccessResponse[paytmResponseCode] = jsonresponse[paytmResponseCode] ?? ""
paytmSuccessResponse[paytmPaymentMode] = jsonresponse[paytmPaymentMode] ?? ""
paytmSuccessResponse[paytmBankTransactionId] = jsonresponse[paytmBankTransactionId] ?? ""
paytmSuccessResponse[paytmCurrency] = jsonresponse[paytmCurrency] ?? ""
paytmSuccessResponse[paytmGatewayName] = jsonresponse[paytmGatewayName] ?? ""
paytmSuccessResponse[paytmResponseMessage] = jsonresponse[paytmResponseMessage] ?? ""
finishWithSuccess(data: paytmSuccessResponse)
catch
finishWithError(errorCode: errorReasonPaytmTransactionResponseNull, errorMessage: "Paytm transaction response in null")
func didCancelTrasaction(_ controller: PGTransactionViewController)
finishWithError(errorCode: errorReasonPaytmTransactionCancelled, errorMessage: "Transaction cancelled.")
func errorMisssingParameter(_ controller: PGTransactionViewController, error: NSError?)
finishWithError(errorCode: errorReasonPaytmMissingParameters, errorMessage: "There are some missing parameters.")
private class PendingOperation
let method: String
let result: FlutterResult
init(method: String, result: @escaping FlutterResult)
self.method = method
self.result = result
public class SwiftFlutterPaytmPlugin: NSObject, FlutterPlugin
//Channel Name Constant
static let channelName = "flutterpaytmplugin.flutter.com/flutter_paytm_plugin"
//Argument Constants
let buildVariant = "build_variant"
let checksumRequestObject = "checksum_request_object"
//Method Constants
let methodInitPaytmService = "initialize_paytm_service"
let methodStartPaymentTransaction = "start_payment_transaction"
var delegate : IDelegate
init(pluginRegistrar: FlutterPluginRegistrar, uiViewController: UIViewController)
delegate = FlutterPaytmPluginDelegate(registrar: pluginRegistrar, viewController: uiViewController)
public static func register(with registrar: FlutterPluginRegistrar)
let channel = FlutterMethodChannel(name: channelName, binaryMessenger: registrar.messenger())
let viewController: UIViewController =
(UIApplication.shared.delegate?.window??.rootViewController)!;
let instance = SwiftFlutterPaytmPlugin(pluginRegistrar: registrar, uiViewController: viewController)
registrar.addMethodCallDelegate(instance, channel: channel)
public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult)
let arguments = call.arguments as? Dictionary<String, Any>
switch call.method
case methodInitPaytmService:
delegate.initializePaytmService(result: result, buildVariant: (arguments?[buildVariant] as? String))
case methodStartPaymentTransaction:
delegate.startPaymentTransaction(result: result, checkSumRequestObject: (arguments?[checksumRequestObject] as? Dictionary<String, String>))
default:
result(FlutterMethodNotImplemented)
我正在关注这个已关闭问题https://github.com/flutter/flutter/issues/9961 的一些建议。
但找不到成功。
这是我得到的日志跟踪：
2018-12-07 17:27:39.510397+0530 Runner[56634:1432738] You've implemented -[<UIApplicationDelegate> application:performFetchWithCompletionHandler:], but you still need to add "fetch" to the list of your supported UIBackgroundModes in your Info.plist.
2018-12-07 17:27:39.510615+0530 Runner[56634:1432738] You've implemented -[<UIApplicationDelegate> application:didReceiveRemoteNotification:fetchCompletionHandler:], but you still need to add "remote-notification" to the list of your supported UIBackgroundModes in your Info.plist.
2018-12-07 17:27:39.610121+0530 Runner[56634:1432850] flutter: Observatory listening on http://127.0.0.1:56923/
PGTransactionViewController:loadView
PGTransactionViewController::viewDidLoad
PGTransactionViewController::viewWillAppear
(lldb)
有一个例外： Exception showcased in the image
请帮帮我。
【问题讨论】：
可以分享一下安卓解决方案吗？ 【参考方案1】：我的一个朋友@virander 帮助我解决了这个问题。他编写了从 swift 插件文件中打开视图控制器的代码。
if let navigationController = UIApplication.shared.keyWindow?.rootViewController as? UINavigationController
navigationController.pushViewController(self.paytmTransactionController!, animated: true)
let storyboard : UIStoryboard? = UIStoryboard.init(name: "Main", bundle: nil);
let window: UIWindow = ((UIApplication.shared.delegate?.window)!)!
let objVC: UIViewController? = storyboard!.instantiateViewController(withIdentifier: "FlutterViewController")
let aObjNavi = UINavigationController(rootViewController: objVC!)
window.rootViewController = aObjNavi
aObjNavi.pushViewController(self.paytmTransactionController!, animated: true)
使用此代码，我可以从 Swift 插件类触发 PayTM 视图控制器。
【讨论】：
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