.NET MAUI · C#

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Recognized locally Payment data RecipientSanitär Krause AmountEUR 359.44 IBANDE58 5705 0120 0094 7103 28 PurposeInvoice 2026-0417 IBAN validated by Docutain

Integrate Photo Payment with .NET MAUI

This guide implements one asynchronous C# flow for Photo Payment on Android and iOS, from initialization to a reviewed payment draft.

The Docutain MAUI package presents native capture UI, recognizes invoice or GiroCode data locally and returns structured JSON. The host application decides how to validate, display and authorize the result.

Targets

Android and iOS

Package

Docutain.SDK.MAUI

API

Async C#

Processing

Local on the device

One C# workflow, two native targets

1. The shared MAUI UI invokes Photo Payment from a user action.
2. Docutain opens the native Android or iOS capture and review interface.
3. The SDK reads a GiroCode when available or extracts payment data from the invoice text.
4. The awaited call returns JSON, an empty result or null.
5. The shared application layer maps the result into its payment model; target-specific authentication and payment handling continue as usual.

Prepare the Android and iOS projects

Android emulators can help with navigation and basic integration checks. On iOS, the app can build and run in the Simulator, but Docutain does not provide functional processing there.

Install and initialize the MAUI SDK

1. Install the NuGet package

dotnet add package Docutain.SDK.MAUI

2. Initialize Docutain once

Initialize the SDK before any feature is enabled. The license is bound to the application's configured identifier.

using Docutain.SDK.MAUI;

public partial class App : Application
{
    public App()
    {
        InitializeComponent();

        if (!DocutainSDK.InitSDK("<YOUR-LICENSE-KEY>"))
        {
            // Initialization failed: capture the SDK error and
            // keep Photo Payment disabled in the application.
            var error = DocutainSDK.LastError;
            HandleInitializationError(error);
        }

        MainPage = new MainPage();
    }
}

Launch Photo Payment asynchronously

Await the native flow so navigation and result handling stay in one explicit control path.

using Docutain.SDK.MAUI;

private async Task StartPhotoPaymentAsync()
{
    try
    {
        var config = new PhotoPaymentConfiguration();
        string? paymentData = await UI.StartPhotoPayment(config);

        if (paymentData is null)
        {
            // The user canceled the flow.
            return;
        }

        if (paymentData.Length == 0)
        {
            // No data was found. This is reachable when the
            // Empty Result Screen has been disabled.
            await ShowManualEntryAsync();
            return;
        }

        // Decode the JSON, apply app rules and prefill a draft.
        ProcessPaymentData(paymentData);
    }
    catch (Exception exception)
    {
        HandlePhotoPaymentError(exception);
    }
}

Map the result into a payment model

The successful result is a JSON string. Parse it into a dedicated DTO rather than binding raw SDK output directly to the transfer screen.

{
  "Address": {
    "Name1": "Sanitär Krause",
    "Zipcode": "56068",
    "City": "Koblenz",
    "Street": "Musterstraße 17",
    "Bank": [{
      "BIC": "MALADE51KOB",
      "IBAN": "DE58570501200094710328"
    }]
  },
  "Date": "2026-04-17",
  "Amount": "359.44",
  "InvoiceId": "2026-0417",
  "Reference": "Invoice 2026-0417",
  "PaymentState": "ToBePaid",
  "SEPACreditor": "Sanitär Krause"
}

SEPACreditor is the payment recipient. Fields may be missing when they are not present or not readable on an invoice. Docutain returns an IBAN only when it is valid; application-level checks still need to confirm the relationship between recipient, IBAN, amount and reference.

Configure analysis and fallback behavior

The default configuration provides capture, review and extraction. Use the same object to tune scan behavior, page editing, onboarding, Scan Tips, colors and the Empty Result Screen.

var config = new PhotoPaymentConfiguration();

// Include the optional paid/to-be-paid classification.
config.AnalyzeConfig.ReadPaymentState = true;

// Keep the default retry guidance during evaluation.
string? paymentData = await UI.StartPhotoPayment(config);

BIC extraction can be disabled if the target payment model does not use it. Keep that decision aligned with the JSON mapping: when BIC is disabled, the bank data shape changes to an IBAN list.

The Empty Result Screen is shown when no IBAN, recipient or amount was found. It gives the user a retry or cancel path; disable it only when the MAUI app supplies equivalent guidance and manual entry.

Test both native implementations, not only shared code

• Use the Android and iOS Showcase Apps for an initial scan-quality check.
• Test the integrated app on representative physical devices for focus, auto-capture and low-light behavior.
• Cover paper invoices, folded pages, PDFs, images and GiroCodes.
• Record correct, missing and incorrect values per payment field and the resulting manual correction effort.
• Verify cancellation, empty results, initialization failure and retry/manual-entry behavior.
• Run target-specific accessibility checks and verify that shared navigation survives app backgrounding.
• Keep recognized invoice data out of crash reports and analytics unless the application's governance explicitly permits it.