Amazon AWS SNS：如何从 iOS 订阅 SNS 主题？答案

【问题标题】：Amazon AWS SNS: How do i subscribe to SNS topic from iOS?Amazon AWS SNS：如何从 iOS 订阅 SNS 主题？
【发布时间】：2015-09-26 19:18:21
【问题描述】：

首先我发现了同样的问题here，但它不起作用......也许AWS SDK发生了变化或其他什么，我不知道为什么......我想从我的订阅SNS主题iOS 应用程序。我正在尝试使用该答案中的代码来做到这一点，我试图对其进行更改以消除错误：

AWSSNS *sns = [AWSSNS defaultSNS];

    AWSSNSCreatePlatformEndpointInput *endpointRequest = [AWSSNSCreatePlatformEndpointInput new];

    endpointRequest.platformApplicationArn = @"arn:aws:sns:us-east-1:753780999999:app/APNS_SANDBOX/MyAppDevelopment";
    endpointRequest.token = [self deviceTokenAsString:deviceToken]; 

    [[[sns createPlatformApplication:endpointRequest] continueWithSuccessBlock:^id(AWSTask *task) {

        AWSSNSCreateEndpointResponse *response = task.result;

        AWSSNSSubscribeInput *subscribeRequest = [AWSSNSSubscribeInput new];

        subscribeRequest.endpoint = response.endpointArn;
        subscribeRequest.protocols = @"application";
        subscribeRequest.topicArn = @"arn:aws:sns:us-east-1:753780999999:MyAppDevelopingTest";

        return [sns subscribe:subscribeRequest];

    }] continueWithBlock:^id(AWSTask *task) {

        if (task.cancelled) {
            NSLog(@"Task cancelled");
        }

        else if (task.error) {
            NSLog(@"Error occurred: [%@]", task.error);
        }

        else {
            NSLog(@"Success");
        }

        return nil;

    }];

但我得到了错误：

Error occurred: [Error Domain=com.amazonaws.AWSSNSErrorDomain Code=0 "The operation couldn’t be completed. (com.amazonaws.AWSSNSErrorDomain error 0.)" UserInfo=0x17ee0950 {Type=Sender, Message=3 validation errors detected: Value null at 'name' failed to satisfy constraint: Member must not be null; Value null at 'attributes' failed to satisfy constraint: Member must not be null; Value null at 'platform' failed to satisfy constraint: Member must not be null, __text=(
    "\n    ",
    "\n    ",
    "\n    ",
    "\n  "
), Code=ValidationError}]

为什么会这样？为什么 app/ 之后资源会被砍掉？除此之外，我不明白我应该把 deviceToken 放在哪里？我真的需要帮助！先谢谢了？

我的 Cognito 角色是：

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "sns:CreatePlatformEndpoint",
                "sns:Subscribe",
                "sns:CreatePlatformApplication",
                "sns:*"
            ],
            "Resource": [
                "arn:aws:sns:*"
            ]
        }
    ]
}

我正在使用最新的 AWS 开发工具包：

Installing AWSCognito 2.2.1 (was 2.2.0)
Installing AWSCore 2.2.1 (was 2.2.0)
Installing AWSSNS 2.2.1 (was 2.2.0)

【问题讨论】：

Message=User: arn:aws:sts::753780999999:assumed-role/Cognito_MyAppUnauth_Role/CognitoIdentityCredentials 无权执行：SNS:CreatePlatformApplication
没有。我试图添加该角色。错误是一样的。我完全不明白为什么要削减资源...为什么“无权执行：SNS:CreatePlatformApplication on resource:arn:aws:sns:us-east-1:753780999999:app/”而不是“arn: aws:sns:us-east-1:753780999999:app/APNS_SANDBOX/MyAppDevelopment"...反正我也不知道怎么回事...
你确定你修改了正确的角色吗？您是否尝试过将资源更改为“*”以查看是否可以解除阻止？
@BobKinney 好的，我将 cognito 的角色修改为 *。现在我有错误：Error occurred: [Error Domain=com.amazonaws.AWSSNSErrorDomain Code=0 "The operation couldn’t be completed. (com.amazonaws.AWSSNSErrorDomain error 0.)" UserInfo=0x17ee0950 {Type=Sender, Message=3 validation errors detected: Value null at 'name' failed to satisfy constraint: Member must not be null; Value null at 'attributes' failed to satisfy constraint: Member must not be null; Value null at 'platform' failed to... 等等...
@BobKinney 我将 continueWithBlock:^id(AWSTask *task) 更改为 AWSTask 并且错误消失了。但我不明白`不兼容的指针类型将 AWSSNSCreatePlatformEndpointInput * 发送到 AWSSNSCreatePlatformApplicationInput * 类型的参数...你说的是最新的 SDK，但我已经在使用 AWS SDK 2.2。

标签： ios objective-c amazon-web-services amazon-sns amazon-cognito

【解决方案1】：

抱歉，很遗憾，您复制的代码中有错字：

createPlatformApplication:endpointRequest

应该是：

createPlatformEndpoint:endpointRequest

您的原始策略中不允许使用 CreatePlatformApplication 方法。允许 sns:* 后，服务允许调用，但请求不包含 CreatePlatformApplication 所需的参数，因此会出现 ValidationError。原始消息中修剪后的 ARN 也是缺少 CreatePlatformApplication 参数的结果。

【讨论】：