1# C# — Azure Functions Isolated Worker Model Triggers & Bindings
2 
3> **Model**: .NET isolated worker model (recommended). Uses attributes on methods/parameters.
4> Import: `using Microsoft.Azure.Functions.Worker;`
5 
6## HTTP Trigger
7 
8```csharp
9[Function("HttpFunction")]
10public static HttpResponseData Run(
11    [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequestData req,
12    FunctionContext context)
13{
14    var response = req.CreateResponse(HttpStatusCode.OK);
15    response.WriteString("Hello!");
16    return response;
17}
18```
19 
20## Blob Storage
21 
22```csharp
23// Trigger (EventGrid source)
24[Function("BlobTrigger")]
25public static void Run(
26    [BlobTrigger("samples-workitems/{name}", Source = BlobTriggerSource.EventGrid,
27     Connection = "AzureWebJobsStorage")] string blobContent,
28    string name, FunctionContext context)
29{
30    context.GetLogger("BlobTrigger").LogInformation($"Blob: {name}");
31}
32 
33// Input
34[BlobInput("input/{name}", Connection = "AzureWebJobsStorage")] string inputBlob
35 
36// Output
37[BlobOutput("output/{name}", Connection = "AzureWebJobsStorage")] out string outputBlob
38```
39 
40## Queue Storage
41 
42```csharp
43// Trigger
44[Function("QueueTrigger")]
45public static void Run(
46    [QueueTrigger("myqueue-items", Connection = "AzureWebJobsStorage")] string message,
47    FunctionContext context)
48{
49    context.GetLogger("Queue").LogInformation($"Message: {message}");
50}
51 
52// Output (via return type)
53[Function("QueueOutput")]
54[QueueOutput("outqueue", Connection = "AzureWebJobsStorage")]
55public static string Run(
56    [HttpTrigger(AuthorizationLevel.Anonymous, "post")] HttpRequestData req)
57{
58    return "queue message";
59}
60```
61 
62## Timer
63 
64```csharp
65[Function("TimerFunction")]
66public static void Run(
67    [TimerTrigger("0 */5 * * * *")] TimerInfo timer,
68    FunctionContext context)
69{
70    context.GetLogger("Timer").LogInformation($"Last: {timer.ScheduleStatus?.Last}");
71}
72```
73 
74## Event Grid
75 
76```csharp
77// Trigger
78[Function("EventGridTrigger")]
79public static void Run(
80    [EventGridTrigger] EventGridEvent eventGridEvent,
81    FunctionContext context)
82{
83    context.GetLogger("EG").LogInformation($"Event: {eventGridEvent.Subject}");
84}
85 
86// Output
87[EventGridOutput(TopicEndpointUri = "MyTopicUri", TopicKeySetting = "MyTopicKey")]
88```
89 
90## Cosmos DB
91 
92```csharp
93// Trigger (Change Feed)
94[Function("CosmosDBTrigger")]
95public static void Run(
96    [CosmosDBTrigger("mydb", "mycontainer",
97     Connection = "CosmosDBConnection",
98     CreateLeaseContainerIfNotExists = true)] IReadOnlyList<MyDocument> documents,
99    FunctionContext context)
100{
101    foreach (var doc in documents)
102        context.GetLogger("Cosmos").LogInformation($"Doc: {doc.Id}");
103}
104 
105// Input
106[CosmosDBInput("mydb", "mycontainer", Connection = "CosmosDBConnection",
107 Id = "{id}", PartitionKey = "{partitionKey}")] MyDocument doc
108 
109// Output
110[CosmosDBOutput("mydb", "mycontainer", Connection = "CosmosDBConnection")]
111```
112 
113## Service Bus
114 
115```csharp
116// Queue Trigger
117[Function("SBQueueTrigger")]
118public static void Run(
119    [ServiceBusTrigger("myqueue", Connection = "ServiceBusConnection")] string message,
120    FunctionContext context)
121{
122    context.GetLogger("SB").LogInformation($"Message: {message}");
123}
124 
125// Topic Trigger
126[Function("SBTopicTrigger")]
127public static void Run(
128    [ServiceBusTrigger("mytopic", "mysubscription",
129     Connection = "ServiceBusConnection")] string message,
130    FunctionContext context)
131{
132    context.GetLogger("SB").LogInformation($"Topic: {message}");
133}
134 
135// Output
136[ServiceBusOutput("outqueue", Connection = "ServiceBusConnection")]
137```
138 
139## Event Hubs
140 
141```csharp
142// Trigger
143[Function("EventHubTrigger")]
144public static void Run(
145    [EventHubTrigger("myeventhub", Connection = "EventHubConnection")] EventData[] events,
146    FunctionContext context)
147{
148    foreach (var e in events)
149        context.GetLogger("EH").LogInformation($"Event: {e.EventBody}");
150}
151 
152// Output
153[EventHubOutput("outeventhub", Connection = "EventHubConnection")]
154```
155 
156## Table Storage
157 
158```csharp
159// Input
160[TableInput("mytable", "{partitionKey}", "{rowKey}",
161 Connection = "AzureWebJobsStorage")] TableEntity entity
162 
163// Output
164[TableOutput("mytable", Connection = "AzureWebJobsStorage")]
165```
166 
167## SQL
168 
169```csharp
170// Trigger
171[Function("SqlTrigger")]
172public static void Run(
173    [SqlTrigger("dbo.MyTable", "SqlConnection")] IReadOnlyList<SqlChange<MyItem>> changes,
174    FunctionContext context)
175{
176    foreach (var change in changes)
177        context.GetLogger("SQL").LogInformation($"Change: {change.Item.Id}");
178}
179 
180// Input
181[SqlInput("SELECT * FROM dbo.MyTable WHERE Id = @Id",
182 "SqlConnection", parameters: "@Id={id}")] IEnumerable<MyItem> items
183 
184// Output
185[SqlOutput("dbo.MyTable", "SqlConnection")]
186```
187 
188## SignalR
189 
190```csharp
191// Output
192[SignalROutput(HubName = "myhub", ConnectionStringSetting = "AzureSignalRConnectionString")]
193```
194 
195## SendGrid
196 
197```csharp
198[SendGridOutput(ApiKey = "SendGridApiKey", From = "[email protected]")]
199```
200 
201## Multiple Outputs
202 
203```csharp
204// Use a custom return type for multiple outputs
205public class MultiOutput
206{
207    [QueueOutput("outqueue", Connection = "AzureWebJobsStorage")]
208    public string QueueMessage { get; set; }
209 
210    public HttpResponseData HttpResponse { get; set; }
211}
212 
213[Function("MultiOutput")]
214public static MultiOutput Run(
215    [HttpTrigger(AuthorizationLevel.Anonymous, "post")] HttpRequestData req)
216{
217    return new MultiOutput
218    {
219        QueueMessage = "new item",
220        HttpResponse = req.CreateResponse(HttpStatusCode.OK)
221    };
222}
223```
224 
225> Full reference: [Azure Functions C# isolated worker guide](https://learn.microsoft.com/en-us/azure/azure-functions/dotnet-isolated-process-guide)
226