Show image in UNNotificationServiceExtension 圖片推播實作方法1 -iOS Swift

Peggy Tsai 

Published in

彼得潘的 Swift iOS App 開發教室

10 min readAug 1, 2023

(UNNotificationServiceExtension, Notification, image)

推播時如果需要帶圖片
可以參考本文

新增Notification Service Extension

到專案設定檔，新增Target

選擇Notification Service Extension，按Next

設定target名稱與資訊

完成新增Notification Service Extension Target

專案會自動掛載Embed Foundation Extension

顯示圖片

在NotificationServiceExtension專案資料夾中，調整NotificationService檔

調整NotificationService檔案如下

import UserNotifications

class NotificationService: UNNotificationServiceExtension {

    var contentHandler: ((UNNotificationContent) -> Void)?
    var bestAttemptContent: UNMutableNotificationContent?

    override func didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler: @escaping (UNNotificationContent) -> Void) {
        self.contentHandler = contentHandler
        bestAttemptContent = (request.content.mutableCopy() as? UNMutableNotificationContent)
        
        if let dictApps = request.content.userInfo["aps"] as? [AnyHashable: Any], let strContent = dictApps["alert"] as? [String: Any], let imagePath = strContent["launch-image"] as? String {
                guard let url = URL(string: imagePath) else {
                    contentHandler(bestAttemptContent)
                    return
                }
                guard let imageData = NSData(contentsOf: url) else {
                    contentHandler(bestAttemptContent)
                    return
                }
                guard let attachment = UNNotificationAttachment.create(imageFileIdentifier: "image.jpg", data: imageData, options: nil) else {
                    print("error in UNNotificationAttachment.create()")
                    contentHandler(bestAttemptContent)
                    return
                }
                bestAttemptContent.attachments = [ attachment ]
            }
            contentHandler(bestAttemptContent)
        }
    }
    
    override func serviceExtensionTimeWillExpire() {
        // Called just before the extension will be terminated by the system.
        // Use this as an opportunity to deliver your "best attempt" at modified content, otherwise the original push payload will be used.
        if let contentHandler = contentHandler, let bestAttemptContent =  bestAttemptContent {
            contentHandler(bestAttemptContent)
        }
    }

}

extension UNNotificationAttachment {
    static func create(imageFileIdentifier: String, data: NSData, options: [NSObject : AnyObject]?) -> UNNotificationAttachment? {
        let fileManager = FileManager.default
        let tmpSubFolderName = ProcessInfo.processInfo.globallyUniqueString
        guard let tmpSubFolderURL = NSURL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(tmpSubFolderName, isDirectory: true) else { return nil }

        do {
            try fileManager.createDirectory(at: tmpSubFolderURL, withIntermediateDirectories: true, attributes: nil)
            let fileURL = tmpSubFolderURL.appendingPathComponent(imageFileIdentifier)
            try data.write(to: fileURL, options: [])
            let imageAttachment = try UNNotificationAttachment(identifier: imageFileIdentifier, url: fileURL, options: options)
            return imageAttachment
        } catch let error {
            print("error \(error)")
        }
        return nil
    }

}

*只需依照後端格式調整 imagePath即可

let dictApps = request.content.userInfo["aps"] as? [AnyHashable: Any], let strContent = dictApps["alert"] as? [String: Any], let imagePath = strContent["launch-image"] as? String

NotificationService 的 Target Membership只需要勾選NotificationServiceExtension

如果是透過Firebase Cloud Messaging with image- FCM推圖
可以參考下方

import UserNotifications
import FirebaseMessaging

class NotificationService: UNNotificationServiceExtension {

    var contentHandler: ((UNNotificationContent) -> Void)?
    var bestAttemptContent: UNMutableNotificationContent?

    override func didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler: @escaping (UNNotificationContent) -> Void) {
        self.contentHandler = contentHandler
        bestAttemptContent = (request.content.mutableCopy() as? UNMutableNotificationContent)
        
        if let bestAttemptContent = bestAttemptContent {
            FIRMessagingExtensionHelper().populateNotificationContent(bestAttemptContent, withContentHandler: contentHandler)
        }
    }
}