---
source_files:
  - Common/DTS.CommonCore/Interface/DownloadData/IDownloadDataView.cs
  - Common/DTS.CommonCore/Interface/DownloadData/IDownloadDataViewModel.cs
generated_at: "2026-04-16T12:17:08.936258+00:00"
model: "zai-org/GLM-5-FP8"
schema_version: 1
sha256: "3467185c7a4c208b"
---

# Documentation: Download Data Interfaces

## 1. Purpose
This module defines the contractual interfaces for the View and ViewModel components within a "Download Data" feature, adhering to a Model-View-ViewModel (MVVM) architectural pattern. It establishes a type hierarchy for download-specific UI components by extending base view and viewModel interfaces, allowing for polymorphic handling of download views within the broader `DTS.Common` system.

## 2. Public Interface

### `IDownloadDataView`
*   **Namespace:** `DTS.Common.Interface`
*   **Inheritance:** `IBaseView`
*   **Signature:**
    ```csharp
    public interface IDownloadDataView : IBaseView
    ```
*   **Description:** A marker interface intended to represent the View layer for a data download operation. It inherits from `IBaseView` but defines no additional members.

### `IDownloadDataViewModel`
*   **Namespace:** `DTS.Common`
*   **Inheritance:** `IBaseViewModel`
*   **Signature:**
    ```csharp
    public interface IDownloadDataViewModel : IBaseViewModel
    ```
*   **Description:** A marker interface intended to represent the ViewModel layer for a data download operation. It inherits from `IBaseViewModel` but defines no additional members.

## 3. Invariants
*   **Base Type Compliance:** Any class implementing `IDownloadDataView` must also implement `IBaseView`. Similarly, any class implementing `IDownloadDataViewModel` must also implement `IBaseViewModel`.
*   **Member Expectations:** As both interfaces currently define no members, they rely entirely on the contracts defined by their parent interfaces (`IBaseView` and `IBaseViewModel`).

## 4. Dependencies
*   **External Dependencies:**
    *   `DTS.Common.Base`: Both interfaces depend on this namespace for `IBaseView` and `IBaseViewModel`.
*   **Dependents:** Unknown from source alone. It is expected that concrete View and ViewModel classes within the "Download Data" feature will implement these interfaces.

## 5. Gotchas
*   **Empty Interfaces:** Both `IDownloadDataView` and `IDownloadDataViewModel` are currently empty (marker interfaces). They do not define properties such as `DownloadCommand`, `ProgressPercentage`, or `Cancel` methods that one might expect for a download feature. Functionality must be inferred from the base interfaces or implemented in concrete classes without interface enforcement.
*   **Namespace Inconsistency:** The View interface (`IDownloadDataView`) resides in `DTS.Common.Interface`, while the ViewModel interface (`IDownloadDataViewModel`) resides in the root `DTS.Common` namespace. This discrepancy may cause confusion regarding file organization or referencing.