Handling password required exception

Signature class supports handling required password exception when opening protected documents over class PasswordRequiredException.

Here are the steps to handle incorrect password exception when working with protected documents with GroupDocs.Signature:

Create new instance of Signature class and pass source document path or stream as a constructor parameter.
Cover the code that works with Signature object methods (Sign, Verify, Search, Update, Delete) with try - catch block including catching PasswordRequiredException exception.

Following example demonstrates how to handle required password exception.

// skip initialization of LoadOptions with Password 
// LoadOptions loadOptions = new LoadOptions(){ Password  = "1234567890" }            
using (Signature signature = new Signature("protectedPwd.pdf"))
{
    try
    {
        QrCodeSignOptions options = new QrCodeSignOptions("JohnSmith")
        {
            EncodeType = QrCodeTypes.QR,
            Left = 100,
            Top = 100
        };
        // try to sign document to file, we expect for PasswordRequiredException
        signature.Sign(outputFilePath, options);
        Console.WriteLine("\nSource document signed successfully.\nFile saved at " + outputFilePath);
    }
    catch(PasswordRequiredException ex)
    {
        Console.WriteLine($"PasswordRequiredException: {ex.Message}");
    }
    catch(GroupDocsSignatureException ex)
    {
        Console.WriteLine($"Common GroupDocsSignatureException: {ex.Message}");
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Common Exception happens only at user code level: {ex.Message}");
    }
    finally
    {
    }
}

More resources

GitHub Examples

You may easily run the code above and see the feature in action in our GitHub examples:

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Handling incorrect document password exception Migration Notes