這是 AWS CDK v2 開發人員指南。較舊的 CDK v1 已於 2022 年 6 月 1 日進入維護，並於 2023 年 6 月 1 日結束支援。

本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。

# 淡化
<a name="facades"></a>

漸層是將資源與應用程式的其他部分連線的類別。每個外觀都以一種資源類型為目標。例如， 類別會命名為 ，`BucketGrants`因為它會授予 Amazon S3 儲存貯體的存取權。淡入會同時使用 L1 (CloudFormation 層級） 和 L2 （意圖型） 建構。

系統會產生一些淡出圖，並準備好用於大多數資源，例如指標和反射類別。其他則針對需要自訂邏輯的資源手動編寫，例如授與類別。

## 授予類別
<a name="facades-grants"></a>

最廣泛使用的 Facades 是 Grants 類別。它們可讓您使用簡單的方法來授予 AWS 資源的存取權。例如，您可以將 `BucketGrants`用於 Amazon S3 儲存貯體，將 `TopicGrants`用於 Amazon SNS 主題。

L2 建構具有`grants`屬性，可輕鬆存取。您也可以使用其原廠方法，從 L1 建構模組建立授與類別。下列範例顯示這兩種方法：

**Example**  

```
import * as s3 from 'aws-cdk-lib/aws-s3';
import * as iam from 'aws-cdk-lib/aws-iam';

// myRole is an IAM role defined elsewhere in your app

// Using grants on an L2 construct (via the grants property)
const l2Bucket = new s3.Bucket(this, 'L2Bucket');
l2Bucket.grants.read(myRole);

// Using grants on an L1 construct (via the factory method)
const l1Bucket = new s3.CfnBucket(this, 'L1Bucket');
s3.BucketGrants.fromBucket(l1Bucket).read(myRole);
```

```
const s3 = require('aws-cdk-lib/aws-s3');
const iam = require('aws-cdk-lib/aws-iam');

// myRole is an IAM role defined elsewhere in your app

// Using grants on an L2 construct (via the grants property)
const l2Bucket = new s3.Bucket(this, 'L2Bucket');
l2Bucket.grants.read(myRole);

// Using grants on an L1 construct (via the factory method)
const l1Bucket = new s3.CfnBucket(this, 'L1Bucket');
s3.BucketGrants.fromBucket(l1Bucket).read(myRole);
```

```
import aws_cdk.aws_s3 as s3
import aws_cdk.aws_iam as iam

# my_role is an IAM role defined elsewhere in your app

# Using grants on an L2 construct (via the grants property)
l2_bucket = s3.Bucket(self, "L2Bucket")
l2_bucket.grants.read(my_role)

# Using grants on an L1 construct (via the factory method)
l1_bucket = s3.CfnBucket(self, "L1Bucket")
s3.BucketGrants.from_bucket(l1_bucket).read(my_role)
```

```
import software.amazon.awscdk.services.s3.*;
import software.amazon.awscdk.services.iam.*;

// myRole is an IAM role defined elsewhere in your app

// Using grants on an L2 construct (via the grants property)
Bucket l2Bucket = new Bucket(this, "L2Bucket");
l2Bucket.getGrants().read(myRole);

// Using grants on an L1 construct (via the factory method)
CfnBucket l1Bucket = new CfnBucket(this, "L1Bucket");
BucketGrants.fromBucket(l1Bucket).read(myRole);
```

```
using Amazon.CDK.AWS.S3;
using Amazon.CDK.AWS.IAM;

// myRole is an IAM role defined elsewhere in your app

// Using grants on an L2 construct (via the grants property)
var l2Bucket = new Bucket(this, "L2Bucket");
l2Bucket.Grants.Read(myRole);

// Using grants on an L1 construct (via the factory method)
var l1Bucket = new CfnBucket(this, "L1Bucket");
BucketGrants.FromBucket(l1Bucket).Read(myRole);
```

```
import (
	"github.com/aws/jsii-runtime-go"
	awss3 "github.com/aws/aws-cdk-go/awscdk/v2/awss3"
)

// myRole is an IAM role defined elsewhere in your app

l2Bucket := awss3.NewBucket(stack, jsii.String("L2Bucket"), nil)
l2Bucket.Grants().Read(myRole, nil)

l1Bucket := awss3.NewCfnBucket(stack, jsii.String("L1Bucket"), nil)
awss3.BucketGrants_FromBucket(l1Bucket).Read(myRole, nil)
```

如需授予和許可的詳細資訊，請參閱[授予](permissions.md#permissions-grants)。

## 搭配 混音使用淡入
<a name="facades-mixins-together"></a>

您可以將 Facades 與 [Mixins](mixins.md) 結合，以獲得 LL1L2-like體驗。使用 Mixins 來設定資源，並使用 Facades 來授予存取權：

**Example**  

```
import * as s3 from 'aws-cdk-lib/aws-s3';
import * as iam from 'aws-cdk-lib/aws-iam';

// Configure the resource with Mixins
const bucket = new s3.CfnBucket(this, 'MyBucket')
  .with(new s3.mixins.BucketVersioning())
  .with(new s3.mixins.BucketBlockPublicAccess());

// Grant permissions using a Facade
const role = new iam.Role(this, 'MyRole', {
  assumedBy: new iam.ServicePrincipal('lambda.amazonaws.com'),
});
s3.BucketGrants.fromBucket(bucket).read(role);
```

```
const s3 = require('aws-cdk-lib/aws-s3');
const iam = require('aws-cdk-lib/aws-iam');

// Configure the resource with Mixins
const bucket = new s3.CfnBucket(this, 'MyBucket')
  .with(new s3.mixins.BucketVersioning())
  .with(new s3.mixins.BucketBlockPublicAccess());

// Grant permissions using a Facade
const role = new iam.Role(this, 'MyRole', {
  assumedBy: new iam.ServicePrincipal('lambda.amazonaws.com'),
});
s3.BucketGrants.fromBucket(bucket).read(role);
```

```
import aws_cdk.aws_s3 as s3
import aws_cdk.aws_iam as iam

# Configure the resource with Mixins
bucket = s3.CfnBucket(self, "MyBucket") \
    .with_(s3.mixins.BucketVersioning()) \
    .with_(s3.mixins.BucketBlockPublicAccess())

# Grant permissions using a Facade
role = iam.Role(self, "MyRole",
    assumed_by=iam.ServicePrincipal("lambda.amazonaws.com"),
)
s3.BucketGrants.from_bucket(bucket).read(role)
```

```
import software.amazon.awscdk.services.s3.*;
import software.amazon.awscdk.services.iam.*;

// Configure the resource with Mixins
CfnBucket bucket = new CfnBucket(this, "MyBucket");
bucket.with(new BucketVersioning());
bucket.with(new BucketBlockPublicAccess());

// Grant permissions using a Facade
Role role = Role.Builder.create(this, "MyRole")
        .assumedBy(new ServicePrincipal("lambda.amazonaws.com"))
        .build();
BucketGrants.fromBucket(bucket).read(role);
```

```
using Amazon.CDK.AWS.S3;
using Amazon.CDK.AWS.IAM;

// Configure the resource with Mixins
var bucket = new CfnBucket(this, "MyBucket");
bucket.With(new BucketVersioning());
bucket.With(new BucketBlockPublicAccess());

// Grant permissions using a Facade
var role = new Role(this, "MyRole", new RoleProps
{
    AssumedBy = new ServicePrincipal("lambda.amazonaws.com")
});
BucketGrants.FromBucket(bucket).Read(role);
```

```
bucket := awss3.NewCfnBucket(stack, jsii.String("MyBucket"), nil)
bucket.With(awss3.NewBucketVersioning())
bucket.With(awss3.NewBucketBlockPublicAccess())

role := awsiam.NewRole(stack, jsii.String("MyRole"), &awsiam.RoleProps{
    AssumedBy: awsiam.NewServicePrincipal(jsii.String("lambda.amazonaws.com"), nil),
})
awss3.BucketGrants_FromBucket(bucket).Read(role, nil)
```

## 相關資源
<a name="facades-related"></a>
+  [混合](mixins.md) – 將可重複使用的功能新增至 L1 和 L2 建構。
+  [授予](permissions.md#permissions-grants) – 在資源之間授予許可。
+  [建構](constructs.md) – 了解 L1, L2 和 L3 建構。