Ios 如何在Swift 4.0中使用Quickblox以编程方式发送推送通知？

我从他们的示例项目中获得了这段代码

    NSString *message = @"Hello man!";
    NSMutableDictionary *payload = [NSMutableDictionary dictionary];
    NSMutableDictionary *aps = [NSMutableDictionary dictionary];
    [aps setObject:@"default" forKey:QBMPushMessageSoundKey];
    [aps setObject:message forKey:QBMPushMessageAlertKey];
    [payload setObject:aps forKey:QBMPushMessageApsKey];
    QBMPushMessage *pushMessage = [[QBMPushMessage alloc] initWithPayload:payload];
    [QBRequest sendPush:pushMessage toUsers:@"292,300,1395" successBlock:^(QBResponse *response, QBMEvent *event) {
        // Successful response with event
    } errorBlock:^(QBError *error) {
        // Handle error
    }];

我把这个换成了

    let mesage = "Hello man!"
    var payload = [String:String]()
    var aps = [String:String]()
    aps[QBMPushMessageSoundKey] = "default"
    aps[QBMPushMessageAlertKey] = mesage
    payload[QBMPushMessageApsKey] = aps //Cannot assign value of type '[String : String]' to type 'String?'
    let message = QBMPushMessage(payload: payload)

为我工作：

let pushMessage = QBMPushMessage()
pushMessage.payloadDict = ["aps":aps]