下面是使用AWS Pinpoint SMS消息属性/元数据的代码示例：

1. 使用AWS SDK for Python (Boto3)：

import boto3

# 创建Pinpoint客户端
client = boto3.client('pinpoint', region_name='us-west-2')

# 定义消息属性/元数据
message_attributes = {
    'CustomerID': {
        'DataType': 'String',
        'StringValue': '12345'
    },
    'OrderID': {
        'DataType': 'String',
        'StringValue': '67890'
    }
}

# 发送短信消息
response = client.send_messages(
    ApplicationId='YOUR_PINPOINT_APP_ID',
    MessageRequest={
        'Addresses': {
            'PhoneNumber': {
                'ChannelType': 'SMS',
                'PhoneNumber': '+1234567890'
            }
        },
        'MessageConfiguration': {
            'SMSMessage': {
                'Body': 'Hello, World!',
                'MessageType': 'TRANSACTIONAL',
                'OriginationNumber': '+0987654321',
                'MessageType': 'TRANSACTIONAL',
                'MessageAttributes': message_attributes
            }
        }
    }
)

print(response)

2. 使用AWS SDK for .NET：

using Amazon.Pinpoint;
using Amazon.Pinpoint.Model;

// 创建Pinpoint客户端
var client = new AmazonPinpointClient();

// 定义消息属性/元数据
var messageAttributes = new Dictionary
{
    { "CustomerID", "12345" },
    { "OrderID", "67890" }
};

// 发送短信消息
var request = new SendMessagesRequest
{
    ApplicationId = "YOUR_PINPOINT_APP_ID",
    MessageRequest = new MessageRequest
    {
        Addresses = new Dictionary
        {
            { "PhoneNumber", new AddressConfiguration { ChannelType = "SMS", PhoneNumber = "+1234567890" } }
        },
        MessageConfiguration = new DirectMessageConfiguration
        {
            SMSMessage = new SMSMessage
            {
                Body = "Hello, World!",
                MessageType = "TRANSACTIONAL",
                OriginationNumber = "+0987654321",
                MessageAttributes = messageAttributes
            }
        }
    }
};

var response = await client.SendMessagesAsync(request);

Console.WriteLine(response);

请确保替换代码示例中的YOUR_PINPOINT_APP_ID、PhoneNumber、OriginationNumber等参数值为实际的值。