Client

The Dapr client package allows you to interact with other Dapr applications from a .NET application.

Prerequisites

Building blocks

The .NET SDK allows you to interface with all of the Dapr building blocks.

Invoke a service

You can either use the DaprClient or System.Net.Http.HttpClient to invoke your services.


using var client = new DaprClientBuilder().Build();

// Invokes a POST method named "deposit" that takes input of type "Transaction"
var data = new { id = "17", amount = 99m };
var account = await client.InvokeMethodAsync<object, Account>("routing", "deposit", data, cancellationToken);
Console.WriteLine("Returned: id:{0} | Balance:{1}", account.Id, account.Balance);

var client = DaprClient.CreateInvokeHttpClient(appId: "routing");

var deposit = new Transaction  { Id = "17", Amount = 99m };
var response = await client.PostAsJsonAsync("/deposit", deposit, cancellationToken);
var account = await response.Content.ReadFromJsonAsync<Account>(cancellationToken: cancellationToken);
Console.WriteLine("Returned: id:{0} | Balance:{1}", account.Id, account.Balance);

Save & get application state

var client = new DaprClientBuilder().Build();

var state = new Widget() { Size = "small", Color = "yellow", };
await client.SaveStateAsync(storeName, stateKeyName, state, cancellationToken: cancellationToken);
Console.WriteLine("Saved State!");

state = await client.GetStateAsync<Widget>(storeName, stateKeyName, cancellationToken: cancellationToken);
Console.WriteLine($"Got State: {state.Size} {state.Color}");

await client.DeleteStateAsync(storeName, stateKeyName, cancellationToken: cancellationToken);
Console.WriteLine("Deleted State!");

Query State (Alpha)

var query = "{" +
                "\"filter\": {" +
                    "\"EQ\": { \"value.Id\": \"1\" }" +
                "}," +
                "\"sort\": [" +
                    "{" +
                        "\"key\": \"value.Balance\"," +
                        "\"order\": \"DESC\"" +
                    "}" +
                "]" +
            "}";

var client = new DaprClientBuilder().Build();
var queryResponse = await client.QueryStateAsync<Account>("querystore", query, cancellationToken: cancellationToken);

Console.WriteLine($"Got {queryResponse.Results.Count}");
foreach (var account in queryResponse.Results)
{
    Console.WriteLine($"Account: {account.Data.Id} has {account.Data.Balance}");
}

Publish messages

var client = new DaprClientBuilder().Build();

var eventData = new { Id = "17", Amount = 10m, };
await client.PublishEventAsync(pubsubName, "deposit", eventData, cancellationToken);
Console.WriteLine("Published deposit event!");

Interact with output bindings

using var client = new DaprClientBuilder().Build();

// Example payload for the Twilio SendGrid binding
var email = new 
{
    metadata = new 
    {
        emailTo = "customer@example.com",
        subject = "An email from Dapr SendGrid binding",    
    }, 
    data =  "<h1>Testing Dapr Bindings</h1>This is a test.<br>Bye!",
};
await client.InvokeBindingAsync("send-email", "create", email);

Retrieve secrets


var client = new DaprClientBuilder().Build();

// Retrieve a key-value-pair-based secret - returns a Dictionary<string, string>
var secrets = await client.GetSecretAsync("mysecretstore", "key-value-pair-secret");
Console.WriteLine($"Got secret keys: {string.Join(", ", secrets.Keys)}");

var client = new DaprClientBuilder().Build();

// Retrieve a key-value-pair-based secret - returns a Dictionary<string, string>
var secrets = await client.GetSecretAsync("mysecretstore", "key-value-pair-secret");
Console.WriteLine($"Got secret keys: {string.Join(", ", secrets.Keys)}");

// Retrieve a single-valued secret - returns a Dictionary<string, string>
// containing a single value with the secret name as the key
var data = await client.GetSecretAsync("mysecretstore", "single-value-secret");
var value = data["single-value-secret"]
Console.WriteLine("Got a secret value, I'm not going to be print it, it's a secret!");

Get Configuration Keys (Alpha)

var client = new DaprClientBuilder().Build();

// Retrieve a specific set of keys.
var specificItems = await client.GetConfiguration("configstore", new List<string>() { "key1", "key2" });
Console.WriteLine($"Here are my values:\n{specificItems[0].Key} -> {specificItems[0].Value}\n{specificItems[1].Key} -> {specificItems[1].Value}");

// Retrieve all configuration items by providing an empty list.
var specificItems = await client.GetConfiguration("configstore", new List<string>());
Console.WriteLine($"I got {configItems.Count} entires!");
foreach (var item in configItems)
{
    Console.WriteLine($"{item.Key} -> {item.Value}")
}

Subscribe to Configuration Keys (Alpha)

var client = new DaprClientBuilder().Build();

// The Subscribe Configuration API returns a wrapper around an IAsyncEnumerable<IEnumerable<ConfigurationItem>>.
// Iterate through it by accessing its Source in a foreach loop. The loop will end when the stream is severed
// or if the cancellation token is cancelled.
var subscribeConfigurationResponse = await daprClient.SubscribeConfiguration(store, keys, metadata, cts.Token);
await foreach (var items in subscribeConfigurationResponse.Source.WithCancellation(cts.Token))
{
    foreach (var item in items)
    {
        Console.WriteLine($"{item.Key} -> {item.Value}")
    }
}