定时触发Azure Function配置多Event Hub输出绑定报错求助

我有一个定时触发的Azure Function，需要根据条件将数据发送到三个不同的Event Hub。我尝试了如下代码：

[FunctionName("TTFunction")]
public async Task RunAsync(
    [TimerTrigger("0 */5 * * * *")]
    [EventHub("EventHubName1", Connection = "EventHubConnection")] IAsyncCollector<string> eventHubName1,
    [EventHub("EventHubName2", Connection = "EventHubConnection")] IAsyncCollector<string> eventHubName2,
    [EventHub("EventHubName3", Connection = "EventHubConnection")] IAsyncCollector<string> eventHubName3)
{
    var msg = JsonConvert.DeserializeObject<MyEvent>("Some Data");

    if (1)
    {
      await eventHubName1.AddAsync(JsonConvert.SerializeObject(msg));
    }
    else if (2)
    {
      await eventHubName2.AddAsync(JsonConvert.SerializeObject(msg));
    }
    else if (3)
    {
      await eventHubName3.AddAsync(JsonConvert.SerializeObject(msg));
    }
}

运行时抛出错误：Multiple bindings with name 'eventHubName1' discovered. Binding names must be unique.。根据微软官方文档，定时触发函数仅支持配置一个Event Hub输出绑定，但我的需求是三个。我的host.json配置如下：

{
  "version": "2.0",
  "logging": {
    "applicationInsights": {
      "samplingSettings": {
        "isEnabled": true,
        "excludedTypes": "Request"
      }
    }
  },
  "extensions": {
    "eventHubs": {
      "transportType": "amqpWebSockets"
    }
  }
}

请问如何实现三个Event Hub输出绑定的需求？

方案一：使用Event Hub SDK直接发送（推荐） #

放弃依赖函数的输出绑定，直接使用Azure.Messaging.EventHubs SDK创建客户端发送消息，这种方式不受函数绑定数量限制，灵活性更高。

步骤：

1. 安装NuGet包Azure.Messaging.EventHubs和Azure.Messaging.EventHubs.Producer
2. 编写代码创建Producer客户端，根据条件发送到对应Event Hub：

using Azure.Messaging.EventHubs;
using Azure.Messaging.EventHubs.Producer;
using Newtonsoft.Json;
using System.Threading.Tasks;
using Microsoft.Azure.WebJobs;
using Microsoft.Extensions.Logging;
using System.Collections.Generic;

[FunctionName("TTFunction")]
public async Task RunAsync(
    [TimerTrigger("0 */5 * * * *")] TimerInfo myTimer,
    ILogger log)
{
    // 模拟数据
    var msg = JsonConvert.DeserializeObject<MyEvent>("Some Data");
    string serializedMsg = JsonConvert.SerializeObject(msg);

    // 存储三个Event Hub的连接字符串（建议配置在Azure Function应用设置中）
    var ehConnectionMap = new Dictionary<int, string>
    {
        { 1, Environment.GetEnvironmentVariable("EventHubConnection1") },
        { 2, Environment.GetEnvironmentVariable("EventHubConnection2") },
        { 3, Environment.GetEnvironmentVariable("EventHubConnection3") }
    };

    int condition = 1; // 替换为你的实际条件判断逻辑

    if (ehConnectionMap.TryGetValue(condition, out string connectionString))
    {
        // 创建Producer客户端并发送消息
        await using var producerClient = new EventHubProducerClient(connectionString);
        using EventDataBatch eventBatch = await producerClient.CreateBatchAsync();
        eventBatch.TryAdd(new EventData(serializedMsg));
        await producerClient.SendAsync(eventBatch);
    }
}

说明：

• 每个Event Hub的连接字符串单独配置在应用设置中，避免硬编码
• 可以通过依赖注入将Producer客户端单例化，减少重复创建连接的开销

方案二：为输出绑定指定唯一名称（兼容函数绑定方式） #

如果必须使用函数的输出绑定，需要为每个Event Hub绑定显式指定唯一的Name属性，解决绑定名称冲突问题：

[FunctionName("TTFunction")]
public async Task RunAsync(
    [TimerTrigger("0 */5 * * * *")] TimerInfo myTimer,
    [EventHub("EventHubName1", Connection = "EventHubConnection", Name = "eh1")] IAsyncCollector<string> eventHubName1,
    [EventHub("EventHubName2", Connection = "EventHubConnection", Name = "eh2")] IAsyncCollector<string> eventHubName2,
    [EventHub("EventHubName3", Connection = "EventHubConnection", Name = "eh3")] IAsyncCollector<string> eventHubName3)
{
    var msg = JsonConvert.DeserializeObject<MyEvent>("Some Data");
    string serializedMsg = JsonConvert.SerializeObject(msg);

    int condition = 1; // 替换为实际条件判断逻辑

    if (condition == 1)
    {
        await eventHubName1.AddAsync(serializedMsg);
    }
    else if (condition == 2)
    {
        await eventHubName2.AddAsync(serializedMsg);
    }
    else if (condition == 3)
    {
        await eventHubName3.AddAsync(serializedMsg);
    }
}

注意：这种方式需要确保你的Functions运行时版本为v2及以上，若仍出现兼容性问题，优先使用方案一。

内容的提问来源于stack exchange，提问作者Shri