Form Designer events in Blazor PDF Viewer

The Blazor PDF Viewer includes Form Designer events to handle form field interactions. These events enable tracking and customizing behaviors such as adding, deleting, selecting, resizing, validating, importing, and exporting form fields.

Event List

Below are the key events provided by the Form Designer to handle form field interactions in the PDF Viewer.

Event Name	Description
FormFieldAdding	Triggered before a new form field is added, allowing validation before insertion.
FormFieldAdded	Triggered when a form field is added to the PDF document.
FormFieldDeleted	Triggered when a form field is removed from the document.
FormFieldClick	Triggered when a user clicks on a form field while designer mode is off.
FormFieldDoubleClick	Triggered when a form field is double-clicked.
FormFieldSelected	Triggered when a form field is selected.
FormFieldUnselected	Triggered when a form field is unselected.
FormFieldResized	Triggered when a form field is resized.
ValidateFormFields	Triggered when form fields are validated.
FormFieldFocusIn	Triggered when focus enters a form field.
FormFieldFocusOut	Triggered when focus leaves a form field.
FormFieldMouseEnter	Triggered when the mouse hovers over a form field.
FormFieldMouseLeave	Triggered when the mouse leaves a form field.
FormFieldPropertyChanged	Triggered when a form field’s properties are modified.
IsDesignerModeChanged	Triggered when the designer mode state changes in the PDF Viewer.
FormFieldsExporting	Triggered before form fields are exported, allowing customization of the export process.
FormFieldsImporting	Triggered before form fields are imported, allowing validation or modifications.
FormFieldsExported	Triggered when form fields are successfully exported.
FormFieldsImported	Triggered when form fields are successfully imported.
FormFieldsExportFailed	Triggered when form fields export operation fails.
FormFieldsImportFailed	Triggered when form fields import operation fails.

FormFieldAdding Event

FormFieldAdding event is triggered before a form field is added in the SfPdfViewer2 component.

The event exposes the Cancel property, which can be set to true to conditionally prevent adding the form field.

Event Arguments

The FormFieldAdding event provides FormFieldAddEventArgs, which includes Field (form field details), PageNumber (target page), and Cancel (to prevent addition).

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldAdding="@OnFormFieldAdding"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";
    void OnFormFieldAdding(FormFieldAddEventArgs args)
    {
        // Access details about the adding form field
        Console.WriteLine($"Form Field being added: {args.Field.Name}");
        args.Cancel = true; // Prevents the form field from being added
        // Additional processing logic
    }
}

By setting args.Cancel = true, the addition of the form field can be conditionally prevented based on custom logic.

FormFieldAdded Event

FormFieldAdded event is triggered whenever a new form field is added to the PDF document. It allows developers to monitor the addition of form fields and apply default properties or validations.

Event Arguments

The FormFieldAdded event provides FormFieldAddedEventArgs, which includes properties like Field (details of the added field) and PageNumber (where the field was added). Developers can use these properties to monitor or modify the added form fields.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldAdded="@OnFormFieldAdded"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";
    void OnFormFieldAdded(FormFieldAddedEventArgs args)
    {
        // Access details about the added form field
        Console.WriteLine($"Form Field added: {args.Field.Name}");
        // Additional processing logic
    }
}

FormFieldDeleted Event

FormFieldDeleted event is triggered when a form field is removed from the document. It can be used to ensure proper cleanup and prevent accidental deletions.

Event Arguments

The FormFieldDeleted event provides FormFieldDeletedEventArgs, which contains properties like Field (deleted field details) and PageNumber. This event helps track and manage field deletions.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldDeleted="@OnFormFieldDeleted"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";

    void OnFormFieldDeleted(FormFieldDeletedEventArgs args)
    {
        // Access details about the deleted form field
        Console.WriteLine($"Form field deleted: {args.Field.Name}");

        // Implement additional logic, such as logging or UI updates
    }
}

FormFieldClick Event

FormFieldClick is triggered when a user clicks on a form field while designer mode is off. This event can be used to display tooltips, highlight fields, or open settings.

Event Arguments

The FormFieldClick event provides FormFieldClickArgs, containing FormField (clicked field details). It enables actions like highlighting fields or opening settings.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldClick="@OnFormFieldClicked"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";
    void OnFormFieldClicked(FormFieldClickArgs args)
    {
        // Access details about the clicked form field
        Console.WriteLine($"Form Field clicked: {args.FormField.Name}");
        // Additional processing logic
    }
}

FormFieldDoubleClick Event

FormFieldDoubleClick is triggered when a form field is double-clicked. This event is useful for triggering additional actions.

Event Arguments

The FormFieldDoubleClick event provides FormFieldDoubleClickEventArgs, which includes Field (double-clicked field details). It is useful for triggering additional actions when a field is double-clicked.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldDoubleClick="@OnFormFieldDoubleClicked"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";

    void OnFormFieldDoubleClicked(FormFieldDoubleClickEventArgs args)
    {
        // Access details about the double clicked form field
        Console.WriteLine($"Form field double clicked: {args.Field.Name}");

        // Implement additional logic, such as logging or UI updates
    }
}

FormFieldSelected Event

FormFieldSelected is triggered when a form field is selected. It can be used to show additional options or highlight the selected field.

Event Arguments

The FormFieldSelected event provides FormFieldSelectedEventArgs, which contains Field (selected field details) and PageNumber. This event helps in handling field selection and UI updates.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldSelected="@OnFormFieldSelected"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";

    void OnFormFieldSelected(FormFieldSelectedEventArgs args)
    {
        // Access details about the selected form field
        Console.WriteLine($"Form field selected: {args.Field.Name}");

        // Implement additional logic, such as logging or UI updates
    }
}

FormFieldUnselected Event

FormFieldUnselected is triggered when a selected form field is unselected. This event helps in resetting UI elements or hiding additional options.

Event Arguments

The FormFieldUnselected event provides FormFieldUnselectedEventArgs, which includes Field (unselected field details). It helps in resetting UI elements or hiding additional options.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldUnselected="@OnFormFieldUnSelected"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";

    void OnFormFieldUnSelected(FormFieldUnselectedEventArgs args)
    {
        // Access details about the unselected form field
        Console.WriteLine($"Form field unselected: {args.Field.Name}");

        // Implement additional logic, such as logging or UI updates
    }
}

FormFieldResized Event

FormFieldResized is triggered when a form field is resized. This event is useful for applying constraints on form field sizes or updating layout dynamically.

Event Arguments

The FormFieldResized event provides FormFieldResizedEventArgs, which contains Field (resized field details) and NewBounds (updated field dimensions). This event allows applying constraints on resizing.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldResized="@OnFormFieldResized"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";

    void OnFormFieldResized(FormFieldResizedEventArgs args)
    {
        // Access details about the resized form field
        Console.WriteLine($"Form field resized: {args.Field.Name}");

        // Implement additional logic, such as logging or UI updates
    }
}

ValidateFormFields Event

ValidateFormFields is triggered when form fields are validated before submission, saving, or printing the PDF. It ensures required fields are completed correctly. To trigger this event, set the EnableFormFieldsValidation property to true in the SfPdfViewer2 component.

Event Arguments

The ValidateFormFields event provides ValidateFormFieldsArgs, which contains Fields (validated form fields). This event ensures that required fields are properly filled.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath" EnableFormFieldsValidation="true">
    <PdfViewerEvents ValidateFormFields="@OnFormFieldValidated"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";

    void OnFormFieldValidated(ValidateFormFieldsArgs args)
    {
        // Access details about the validated form field
        Console.WriteLine($"Form field Validated: {args.Fields[0].Name}");

        // Implement additional logic, such as logging or UI updates
    }
}

FormFieldFocusIn Event

FormFieldFocusIn occurs when focus enters a form field while designer mode is disabled. Typical uses include applying dynamic styling, showing inline help, or suggesting values.

Event Arguments

The FormFieldFocusIn event provides FormFieldFocusInEventArgs, which includes Field (details of the focused form field). Use it to identify the target field for styling or tooltips when focus is gained.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath" EnableFormFieldsValidation="true">
    <PdfViewerEvents FormFieldFocusIn="@OnFormFieldFocusIn"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";

    void OnFormFieldFocusIn(FormFieldFocusInEventArgs args)
    {
        // Access details about the focused in form field
        Console.WriteLine($"Form field focused in: {args.Field.Name}");

        // Implement additional logic, such as logging or UI updates
    }
}

FormFieldFocusOut Event

FormFieldFocusOut occurs when focus leaves a form field while designer mode is disabled. Common scenarios include validating input, persisting values, or cleaning up UI state.

Event Arguments

The FormFieldFocusOut event provides FormFieldFocusOutEventArgs, which includes Field (the form field losing focus). Use it to validate or save data when the user moves out of a field.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath" EnableFormFieldsValidation="true">
    <PdfViewerEvents FormFieldFocusOut="@OnFormFieldFocusOut"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";

    void OnFormFieldFocusOut(FormFieldFocusOutEventArgs args)
    {
        // Access details about the focused out form field
        Console.WriteLine($"Form field focused out: {args.Field.Name}");

        // Implement additional logic, such as logging or UI updates
    }
}

FormFieldMouseEnter Event

FormFieldMouseEnter occurs when the pointer enters a form field in the PDF Viewer. It is useful for hover styling, showing tooltips, or previewing context-sensitive help.

Event Arguments

The FormFieldMouseEnter event provides FormFieldMouseEnterEventArgs, which includes properties like Field (the form field entered) and PageNumber (page containing the field). Use this to tailor hover behavior based on field and page context.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldMouseEnter="@OnFormFieldMouseEnter"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";

    void OnFormFieldMouseEnter(FormFieldMouseEnterEventArgs args)
    {
        // Access details about the mouse entered form field
        Console.WriteLine($"Form field Mouse entered: {args.Field.Name}");

        // Implement additional logic, such as logging or UI updates
    }
}

FormFieldMouseLeave Event

FormFieldMouseLeave occurs when the pointer leaves a form field. Typical uses include hiding tooltips and reverting hover styling.

Event Arguments

The FormFieldMouseLeave event provides FormFieldMouseLeaveEventArgs, which includes properties like Field (the form field exited) and PageNumber. Use it to revert UI changes when the pointer moves away.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldMouseLeave="@OnFormFieldMouseLeave"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";

    void OnFormFieldMouseLeave(FormFieldMouseLeaveEventArgs args)
    {
        // Access details about the mouse leaved form field
        Console.WriteLine($"Form field Mouse leaved: {args.Field.Name}");

        // Implement additional logic, such as logging or UI updates
    }
}

FormFieldPropertyChanged Event

FormFieldPropertyChanged occurs when a form field’s properties are modified. This is useful for tracking changes, synchronizing UI, or enforcing rules based on property updates.

Event Arguments

The FormFieldPropertyChanged event provides FormFieldPropertyChangedEventArgs, which contains properties like OldValue and NewValue. Use these to compare changes and trigger dependent updates or validations.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldPropertyChanged="@OnFormFieldPropertyChanged"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";

    void OnFormFieldPropertyChanged(FormFieldPropertyChangedEventArgs args)
    {
        // Access details about the property changed form field
        Console.WriteLine($"Form field property changed: {args.NewValue}");

        // Implement additional logic, such as logging or UI updates
    }
}

IsDesignerModeChanged Event

IsDesignerModeChanged occurs whenever the component’s designer mode is enabled or disabled. It can be used to adjust UI, toggle interactions, or record mode changes.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.SfPdfViewer;

<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath" IsDesignerModeChanged="IsDesignerModeChanged">
</SfPdfViewer2>

@code {
    private string DocumentPath = "wwwroot/data/events.pdf";

    void IsDesignerModeChanged(bool args)
    {
        // Check the state of Designer mode
        Console.WriteLine($"Designer mode is: {args}");

        // Implement additional logic, such as logging or UI updates
    }
}

FormFieldsExporting Event

FormFieldsExporting occurs when the form fields export process begins. It enables customization of the export payload or process, including validation or transformation, and the operation can be canceled by setting args.Cancel = true.

Event Arguments

The FormFieldsExporting event provides FormFieldsExportEventArgs, which includes properties like Cancel. Use it to modify the export payload, validate data, or cancel the operation when necessary.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.Buttons;
@using Syncfusion.Blazor.SfPdfViewer;

<SfButton OnClick="ExportFields">Export Form Fields</SfButton>
<SfPdfViewer2 @ref="Viewer" Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldsExporting="OnFormFieldsExporting"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    SfPdfViewer2? Viewer;
    private string DocumentPath = "wwwroot/data/events.pdf";
    Stream JSONStream = new MemoryStream();

    void OnFormFieldsExporting(FormFieldsExportEventArgs args)
    {
        Console.WriteLine($"Form fields are being exported");

        args.Cancel = true; // Cancels the export process

        // Implement additional logic, such as logging or UI updates
    }

    private async void ExportFields()
    {
        // Export form fields as JSON Stream
        if (Viewer != null)
        {
            JSONStream = await Viewer.ExportFormFieldsAsync(FormFieldDataFormat.Json);
        }
    }
}

FormFieldsImporting Event

FormFieldsImporting occurs when the form-fields import process begins. Use this event to validate or modify incoming form-field data before it is applied. Cancel the operation by setting the event argument’s Cancel property to true.

Event Arguments

The FormFieldsImporting event provides FormFieldsImportEventArgs, which includes properties such as Cancel. Use this to stop the import or adjust data prior to import.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.Buttons;
@using Syncfusion.Blazor.SfPdfViewer;

<SfButton OnClick="ExportFields">Export Form Fields</SfButton>
<SfButton OnClick="ImportFields">Import Form Fields</SfButton>
<SfPdfViewer2 @ref="Viewer" Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldsImporting="OnFormFieldsImporting"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    SfPdfViewer2? Viewer;
    private string DocumentPath = "wwwroot/data/events.pdf";
    Stream JSONStream = new MemoryStream();

    void OnFormFieldsImporting(FormFieldsImportEventArgs args)
    {
        Console.WriteLine($"Form fields are being imported");

        args.Cancel = true; //cancels the import process

        // Implement additional logic, such as logging or UI updates
    }

    private async void ExportFields()
    {
        // Export form fields as JSON Stream
        if (Viewer != null)
        {
            JSONStream = await Viewer.ExportFormFieldsAsync(FormFieldDataFormat.Json);
        }
    }

    private async void ImportFields()
    {
        // Import form fields as JSON Stream
        if (JSONStream != null && Viewer != null)
        {
            // Import JSON data into the viewer
            await Viewer.ImportFormFieldsAsync(JSONStream, FormFieldDataFormat.Json);
        }
    }
}

FormFieldsExported Event

FormFieldsExported occurs after form fields are exported successfully. Use this event to continue workflows such as saving, auditing, or notifying the user.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.Buttons;
@using Syncfusion.Blazor.SfPdfViewer;

<SfButton OnClick="ExportFields">Export Form Fields</SfButton>
<SfPdfViewer2 @ref="Viewer" Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldsExported="OnFormFieldsExported"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    SfPdfViewer2? Viewer;
    private string DocumentPath = "wwwroot/data/events.pdf";
    Stream JSONStream = new MemoryStream();

    void OnFormFieldsExported(FormFieldsExportedEventArgs args)
    {
        Console.WriteLine($"Form fields are exported Successfully");
        // Implement additional logic, such as logging or UI updates
    }

    private async void ExportFields()
    {
        // Export form fields as JSON Stream
        if (Viewer != null)
        {
            JSONStream = await Viewer.ExportFormFieldsAsync(FormFieldDataFormat.Json);
        }
    }
}

FormFieldsImported Event

FormFieldsImported occurs after form fields are imported into the document. Use this event to map imported values to application data, refresh UI state, or log completion.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.Buttons;
@using Syncfusion.Blazor.SfPdfViewer;

<SfButton OnClick="ExportFields">Export Form Fields</SfButton>
<SfButton OnClick="ImportFields">Import Form Fields</SfButton>
<SfPdfViewer2 @ref="Viewer" Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldsImported="OnFormFieldsImported"></PdfViewerEvents>
</SfPdfViewer2>
@code {
    SfPdfViewer2? Viewer;
    private string DocumentPath = "wwwroot/data/events.pdf";
    Stream JSONStream = new MemoryStream();
    void OnFormFieldsImported(FormFieldsImportedEventArgs args)
    {
        Console.WriteLine($"Form fields are imported Successfully");
        // Implement additional logic, such as logging or UI updates
    }
    private async void ExportFields()
    {
        // Export form fields as JSON Stream
        if (Viewer != null)
        {
            JSONStream = await Viewer.ExportFormFieldsAsync(FormFieldDataFormat.Json);
        }
    }
    private async void ImportFields()
    {
        // Import form fields as JSON Stream
        if (JSONStream != null && Viewer != null)
        {
            // Import JSON data into the viewer
            await Viewer.ImportFormFieldsAsync(JSONStream, FormFieldDataFormat.Json);
        }
    }
}

FormFieldsExportFailed Event

FormFieldsExportFailed occurs when the export operation fails. Handle this event to capture error details, log issues, and provide fallback actions.

Event Arguments

The event provides FormFieldsExportFailedEventArgs, which includes ErrorDetails describing the failure. Use this information to diagnose and recover from export errors.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.Buttons;
@using Syncfusion.Blazor.SfPdfViewer;

<SfButton OnClick="ExportFields">Export Form Fields</SfButton>
<SfPdfViewer2 @ref="Viewer" Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldsExportFailed="OnFormFieldsExportFailed"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    SfPdfViewer2? Viewer;
    private string DocumentPath = "wwwroot/data/events.pdf";
    Stream JSONStream = new MemoryStream();

    void OnFormFieldsExportFailed(FormFieldsExportFailedEventArgs args)
    {
        Console.WriteLine($"Form field export is failed: {args.ErrorDetails}");
        // Implement additional logic, such as logging or UI updates
    }

    private async void ExportFields()
    {
        // Export form fields as JSON Stream
        if (Viewer != null)
        {
            JSONStream = await Viewer.ExportFormFieldsAsync(FormFieldDataFormat.Json);
        }
    }
}

FormFieldsImportFailed Event

FormFieldsImportFailed occurs when the import operation fails. Handle this event to surface errors to the user, capture diagnostics, and attempt recovery.

Event Arguments

The event provides FormFieldsImportFailedEventArgs, which includes ErrorDetails explaining the cause. Use this to troubleshoot and implement fallback mechanisms.

@using Syncfusion.Blazor;
@using Syncfusion.Blazor.Buttons;
@using Syncfusion.Blazor.SfPdfViewer;

<SfButton OnClick="ExportFields">Export Form Fields</SfButton>
<SfButton OnClick="ImportFields">Import Form Fields</SfButton>
<SfPdfViewer2 @ref="Viewer" Height="100%" Width="100%" DocumentPath="@DocumentPath">
    <PdfViewerEvents FormFieldsImportFailed="OnFormFieldsImportFailed"></PdfViewerEvents>
</SfPdfViewer2>

@code {
    SfPdfViewer2? Viewer;
    private string DocumentPath = "wwwroot/data/events.pdf";
    Stream JSONStream = new MemoryStream();

    void OnFormFieldsImportFailed(FormFieldsImportFailedEventArgs args)
    {
        Console.WriteLine($"Form field Import is failed: {args.ErrorDetails}");
        // Implement additional logic, such as logging or UI updates
    }

    private async void ExportFields()
    {
        // Export form fields as JSON Stream
        if (Viewer != null)
        {
            JSONStream = await Viewer.ExportFormFieldsAsync(FormFieldDataFormat.Json);
        }
    }

    private async void ImportFields()
    {
        // Import form fields as JSON Stream
        if (JSONStream != null && Viewer != null)
        {
            // Import JSON data into the viewer
            await Viewer.ImportFormFieldsAsync(JSONStream, FormFieldDataFormat.Json);
        }
    }
}

View the complete sample on GitHub.

Form Designer events in Blazor PDF Viewer

Event List

FormFieldAdding Event

Event Arguments

FormFieldAdded Event

Event Arguments

FormFieldDeleted Event

Event Arguments

FormFieldClick Event

Event Arguments

FormFieldDoubleClick Event

Event Arguments

FormFieldSelected Event

Event Arguments

FormFieldUnselected Event

Event Arguments

FormFieldResized Event

Event Arguments

ValidateFormFields Event

Event Arguments

FormFieldFocusIn Event

Event Arguments

FormFieldFocusOut Event

Event Arguments

FormFieldMouseEnter Event

Event Arguments

FormFieldMouseLeave Event

Event Arguments

FormFieldPropertyChanged Event

Event Arguments

IsDesignerModeChanged Event

FormFieldsExporting Event

Event Arguments

FormFieldsImporting Event

Event Arguments

FormFieldsExported Event

FormFieldsImported Event

FormFieldsExportFailed Event

Event Arguments

FormFieldsImportFailed Event

Event Arguments

See also