C# - Ditto

This content is for SDK V4. For the latest version, see the V5 documentation.

To install the C# SDK:

Confirm that you meet the minimum requirements. (Prerequisites)

Install the Ditto SDK. (Installing Dependencies)

Set up your app permissions. (Configuring Permissions)

Add Ditto to your app. (Initializing Ditto)

(Optional) Declare a foreground service (Android only). (Declaring a Foreground Service)

Prerequisites

Following are the minimum requirements that must be met before attempting to install Ditto:

A .NET Standard 2.0 compatible installation (starting with 4.14.4; earlier 4.x releases require .NET Standard 2.1).
.NET Framework 4.8 is supported starting with 4.14.4.
.NET 8 or higher if you are targeting .NET MAUI

Installing Dependencies

To use the Ditto SDK in your project, you’ll need to install the appropriate NuGet package.

If using a package manager other than NuGet, the official package manager for .NET, the command syntax to install Ditto may differ from the following snippet. For more information, see the official Nuget documentation > Ditto .NET

Install-Package Ditto -Version 4.14.4

.NET Framework 4.8+ setup

Ditto supports .NET Framework 4.8 and 4.8.1 via the netstandard2.0 asset shipped in Ditto 4.14.4 and later in the 4.x line. Earlier 4.x releases (4.14.3 and below) target netstandard2.1, which is not consumable from .NET Framework.

PackageReference (SDK-style csproj)
packages.config (classic WinForms / WPF / ASP.NET)

Install the Ditto NuGet package and you are done. No additional steps are required.

packages.config does not automatically resolve native runtime assets from NuGet packages. After installing the Ditto NuGet package, add the following to your .csproj, adjusting the version segment in the path to match your installed version:

csproj

<ItemGroup>
  <Content Include="packages\Ditto.Native.Win.4.14.4\runtimes\win-x64\native\dittoffi.dll">
    <Link>dittoffi.dll</Link>
    <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
  </Content>
</ItemGroup>

You install the top-level Ditto NuGet package (the install command is still Install-Package Ditto). The <Content Include> path references Ditto.Native.Win only because that is the package the native binary ships in — Ditto.Native.Win is a dependency of Ditto and should not be installed directly.

Multi-project solutions: if Ditto is used by a class library referenced by your .exe, install the Ditto package directly on the .exe (startup) project as well. Native DLLs do not propagate through <ProjectReference> chains in .NET Framework. Architecture: the Ditto native DLL is Windows x64 only. Ensure your project has <PlatformTarget>x64</PlatformTarget> and <Prefer32Bit>false</Prefer32Bit>. Older WinForms templates default to “AnyCPU + Prefer 32-bit,” which loads as a 32-bit process and fails to load the x64 native DLL. For a working reference, see the dotnet-winforms-net48 sample on GitHub.

Troubleshooting

System.DllNotFoundException: Unable to load DLL 'dittoffi' (HRESULT 0x8007007E): The native DLL is not in the runtime output directory of your .exe. For packages.config projects, confirm the <Content Include> entry shown above is present in the .exe project’s csproj (not just a referenced library) and that the path resolves to a real file on disk. For PackageReference projects, ensure <RuntimeIdentifier>win-x64</RuntimeIdentifier> is set on the .exe project.
System.BadImageFormatException (HRESULT 0x8007000B): The native DLL is being found, but its architecture does not match the process. Confirm your .exe project has <PlatformTarget>x64</PlatformTarget> and <Prefer32Bit>false</Prefer32Bit>. The dotnet-winforms-net48 sample shows the correct settings.

Configuring Permissions

To set up your environment for your target platform:

iOS Target
Android Target
Mac Catalyst Target

For apps targeting iOS; for example, MAUI, once you’ve added the Ditto package dependency, configure permissions and ensure your app continues syncing while running in the background, including when the end-user device is locked, by enabling background modes.

Open the Info.Plist file for your project.

Add the following key-value pairs, and then, if desired, modify each string value:

XML

<key>NSBluetoothAlwaysUsageDescription</key>
<string>Uses Bluetooth to connect and sync with nearby devices</string>
<key>NSLocalNetworkUsageDescription</key>
<string>Uses WiFi to connect and sync with nearby devices</string>
<key>NSBonjourServices</key>
<array>
<string>_http-alt._tcp.</string>
</array>

Enable Bluetooth Background Modes:

XML

<key>UIBackgroundModes</key>
<array>
<string>bluetooth-central</string>
<string>bluetooth-peripheral</string>
</array>

For apps targeting Android, once you’ve added the Ditto package dependency, configure the necessary permissions:

Open the AndroidManifest.xml file typically located in the src/main/ directory of your project.

Add the necessary permissions to ensure your app has the permissions required by Ditto:

For instructions on how to modify the following configuration for permissions requests; for example, prevent your app from requesting unnecessary permissions on newer OS versions or ensure compatibility with both older and newer OS versions, see Customizing Permissions below.

XML

<manifest
xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android">
<uses-permission android:name="android.permission.BLUETOOTH"
android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"
android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.BLUETOOTH_ADVERTISE"
tools:targetApi="s" />
<uses-permission android:name="android.permission.BLUETOOTH_CONNECT"
tools:targetApi="s" />
<uses-permission android:name="android.permission.BLUETOOTH_SCAN"
android:usesPermissionFlags="neverForLocation"
tools:targetApi="s" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"
android:maxSdkVersion="32" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"
android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission
android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.NEARBY_WIFI_DEVICES"
android:usesPermissionFlags="neverForLocation"
tools:targetApi="tiramisu" />

Customizing Permissions

To modify the behavior of permission requests for the Android target:

Add the following namespace attribute to the root <manifest> tag of your AndroidManifest.xml file:

xmlns:tools="http://schemas.android.com/tools"

To request permissions on all OS versions of Android:

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"
tools:remove="android:maxSdkVersion" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"
tools:remove="android:maxSdkVersion" />

To limit permissions request, use the following attributes as desired:

tools:targetApi
android:maxSdkVersion

tools:targetApi

The tools:targetApi attribute allows you to specify that a permission should only be requested on devices running a specified Android API level or higher.By limiting permissions requests, you prevent errors that result from asking permissions on devices running older OS versions of Android.

android:maxSdkVersion

With the android:maxSdkVersion attribute, you can customize to only initiate a permission request on devices running a specified Android API level or lower.Setting to a specified API level or lower helps avoids unnecessary permissions requests on devices running newer OS versions of Android.

For apps targeting macOS via Mac Catalyst, once you’ve added the Ditto package dependency, you’ll need to request permission for Bluetooth and local networking access.

Open the Info.plist file for your Mac Catalyst target.

Add the following key-value pairs to request access to Bluetooth and local networking:

XML

<key>NSBluetoothAlwaysUsageDescription</key>
<string>Uses Bluetooth to connect and sync with nearby devices</string>
<key>NSLocalNetworkUsageDescription</key>
<string>Uses WiFi to connect and sync with nearby devices</string>
<key>NSBonjourServices</key>
<array>
<string>_http-alt._tcp.</string>
</array>

Requesting Permissions at Runtime

In addition to being declared, some permissions need to be requested from the user at runtime. To ensure your app has the required permissions for sync, use the DittoSyncPermissions helper class from the Ditto SDK. This helper class simplifies the process of requesting end-user permissions at runtime with a single method call for all necessary permissions. Ensure StartSync() is invoked after permissions have been requested.

public async Task CheckPermissions()
{
    await DittoSyncPermissions.RequestPermissionsAsync();
    ditto.StartSync();;
}

Initializing Ditto

Once you’ve installed the Ditto SDK, set the debug level you want Ditto to log messages for, create a new Ditto identity, and set up Ditto exception handling for data sync operations:

var identity = DittoIdentity.OnlinePlayground(
    appId, 
    playgroundToken, 
    false, // This is required to be set to false to use the correct URLs
    authUrl);

ditto = new Ditto(identity, tempDir);

ditto.UpdateTransportConfig(config =>
{
    // Set the Ditto Websocket URL
    config.Connect.WebSocketUrls.Add("wss://REPLACE_ME_WITH_YOUR_WEBSOCKET_URL");
});

// Disable DQL strict mode so that collection definitions are not required in DQL queries
await ditto.Store.ExecuteAsync("ALTER SYSTEM SET DQL_STRICT_MODE = false");

ditto.StartSync();

Declaring a Foreground Service (Android Only)

A foreground service allows your app to continue syncing data with Ditto while running in the background. A foreground service is not required to use Ditto, but without it your app will stop syncing whenever it is in the background. To declare the foreground service, add the following to your AndroidManifest.xml:

<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<uses-permission android:name="android.permission.FOREGROUND_SERVICE_CONNECTED_DEVICE" tools:targetApi="upside_down_cake" />
<uses-permission android:name="android.permission.POST_NOTIFICATIONS" tools:targetApi="tiramisu" />

<application ...>
    <service
        android:name="live.ditto.transports.foregroundservice.DefaultDittoForegroundService"
        android:exported="false"
        android:foregroundServiceType="connectedDevice"
        android:stopWithTask="true">
        <meta-data android:name="notificationChannelName" android:value="Background Data Sync" />
        <meta-data android:name="notificationChannelId" android:value="BackgroundDataSyncId" />
        <meta-data android:name="smallIcon" android:resource="@drawable/small_app_icon" />
        <meta-data android:name="notificationTitle" android:value="Syncing Data" />
        <meta-data android:name="notificationText" android:value="Syncing data across connected devices" />
        <meta-data android:name="notificationId" android:value="1001" />
    </service>
</application>

Make sure you customize the service metadata—it will be displayed to the user in the foreground service notification. Note that your small_app_icon drawable must be monochrome white. The foreground service will be automatically started and stopped on startSync() and stopSync(), respectively.

Next Steps

Learn how to build a task list app built on .NET and integrated with Ditto by going to the .NET MAUI or .NET TUI quickstart apps.

​Prerequisites

​Installing Dependencies

​.NET Framework 4.8+ setup

​Troubleshooting

​Configuring Permissions

​Customizing Permissions

​tools:targetApi

​android:maxSdkVersion

​Requesting Permissions at Runtime

​Initializing Ditto

​Declaring a Foreground Service (Android Only)

​Next Steps

Prerequisites

Installing Dependencies

.NET Framework 4.8+ setup

Troubleshooting

Configuring Permissions

Customizing Permissions

tools:targetApi

android:maxSdkVersion

Requesting Permissions at Runtime

Initializing Ditto

Declaring a Foreground Service (Android Only)

Next Steps