aws Fn.import_value返回令牌，忽略桶名的cloudformation输出，并显示令牌

Question

成功地"cdk部署CdkS3Stack“之后，输出将在CloudFormationConsole和cdk输出中正确显示。

from aws_cdk import (
    Stack,
    aws_s3 as _s3,
    CfnOutput
)

from constructs import Construct

class CdkS3Stack(Stack):

    def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
        super().__init__(scope, construct_id, **kwargs)

        bucket_proto = _s3.Bucket(self, id = "protoBucket",
            block_public_access=_s3.BlockPublicAccess.BLOCK_ALL,
            encryption=_s3.BucketEncryption.S3_MANAGED,
            versioned=False
        )

        bucket_json = _s3.Bucket(self, id = "jsonBucket",
            block_public_access = _s3.BlockPublicAccess.BLOCK_ALL,
            encryption=_s3.BucketEncryption.S3_MANAGED,
            versioned=False
        )

        # #Output of created resource
        CfnOutput(scope=self, id='PROTOBUCKETNAME',
                        value=bucket_proto.bucket_name)
        CfnOutput(scope=self, id='PROTOBUCKETARN',
                        value=bucket_proto.bucket_arn)
        CfnOutput(scope=self, id='JSONBUCKETNAME',
                        value=bucket_json.bucket_name)
        CfnOutput(scope=self, id='JSONBUCKETARN',
                        value=bucket_json.bucket_arn)

**然而，当我试图访问输出时，在正确获取输入时会出现问题。print语句显示如下，尽管在cloudformation和命令行输出中正确地显示了输出。

protobucket ${Token[TOKEN.255]}
jsonbucket ${Token[TOKEN.256]}    
protobucketarn ${Token[TOKEN.257]}

最后，下面的堆栈在部署阶段"cdk部署CdkLambdaStack“上失败，并出现错误”named“。我们试图在lambda堆栈中使用Fn.import_value获取上面的输入的代码如下：

CdkLambdaStack: creating CloudFormation changeset...
CdkLambdaStack | 0/10 | 1:50:25 AM | UPDATE_IN_PROGRESS   | AWS::CloudFormation::Stack    | CdkLambdaStack User Initiated
CdkLambdaStack | 0/10 | 1:50:28 AM | UPDATE_ROLLBACK_IN_P | AWS::CloudFormation::Stack    | CdkLambdaStack No export named PROTOBUCKETARN foundCdkLambdaStack | 1/10 | 1:50:33 AM | UPDATE_ROLLBACK_COMP | AWS::CloudFormation::Stack    | CdkLambdaStack 
CdkLambdaStack | 2/10 | 1:50:33 AM | UPDATE_ROLLBACK_COMP | AWS::CloudFormation::Stack    | CdkLambdaStack 

from aws_cdk import (
   Stack,
   aws_lambda as _lambda,
   aws_iam as _iam,
   Fn,
   aws_s3 as _s3,
   aws_s3_notifications as _s3n
   #CfnOutput
)

from constructs import Construct

class CdkLambdaStack(Stack):

   def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
       super().__init__(scope, construct_id, **kwargs)
       #Create role for your Lambda function
       lambda_role = _iam.Role(scope=self, id='cdk-lambda-role',
                               assumed_by =_iam.ServicePrincipal('lambda.amazonaws.com'),
                               role_name='cdk-lambda-role',
                               managed_policies=[
                               _iam.ManagedPolicy.from_aws_managed_policy_name(
                                   'AWSLambda_FullAccess'),
                               _iam.ManagedPolicy.from_aws_managed_policy_name(
                                   'CloudWatchFullAccess'),
                               _iam.ManagedPolicy.from_aws_managed_policy_name(
                                   'AmazonS3FullAccess')    
                               ])

       lambdaLayer = _lambda.LayerVersion(self, 'lambda-layer',
                 code = _lambda.AssetCode('./cdk_lambda_stack/lambda/layer/'),
                 compatible_runtimes = [_lambda.Runtime.PYTHON_3_9],
       )          
       
       proto_bucket = Fn.import_value("PROTOBUCKETNAME")     <----
       json_bucket = Fn.import_value("JSONBUCKETNAME")       <----
       proto_bucket_arn = Fn.import_value("PROTOBUCKETARN")   <----

       print("protobucket", proto_bucket)
       print("jsonbucket", json_bucket)
       print("protobucketarn", proto_bucket_arn)
       # Defines an AWS Lambda resource
       cdk_lambda = _lambda.Function(
           self, 'cdk-lambda-func',
           runtime=_lambda.Runtime.PYTHON_3_9,
           function_name='cdk-lambda-function',
           description='Lambda function deployed using AWS CDK Python',
           code=_lambda.Code.from_asset('./cdk_lambda_stack/lambda/code'),
           handler='my_lambda_code.lambda_handler',
           role=lambda_role,
           layers = [lambdaLayer],
           environment={
               'NAME': 'cdk-lambda-function-env',
               'PROTO_BUCKET': proto_bucket,
               'JSON_BUCKET': json_bucket
           }
       )
       proto_bucket_ref = _s3.Bucket.from_bucket_arn(self, id = "protoBucket-abc",
             bucket_arn = proto_bucket_arn)              <------
       proto_bucket_ref.add_event_notification(_s3.EventType.OBJECT_CREATED,
             _s3n.LambdaDestination(cdk_lambda))    <-------

我做错什么了？输出应该在那里，可以看到。如果我注释掉用箭头(即lambda堆栈中的交叉堆栈引用)指示的行来读取输出，那么就没有错误。。

Answer 1

输出应该使用export_name完成，而Fn.import_value应该在另一个堆栈中使用export_name完成：

堆栈1：

CfnOutput(scope=self，id='PROTOBUCKETNAME'，export_name="ProtoBuf:BucketName"，description=“Probuf桶名”，value=bucket_proto.bucket_name)

第2组：

proto_bucket_name = Fn.import_value("ProtoBuf:BucketName")