BackgroundBuilder

An MVVM WPF application (.NET 6) providing an Excel-like editor for the contatos table in PostgreSQL.

Prerequisites

• .NET 6 SDK

• PostgreSQL database with table:

  ```sql
  CREATE TABLE public.contatos (
      ramal text PRIMARY KEY NOT NULL,
      nome text NOT NULL,
      email text,
      area text,
      aniversario date,
      "isComando" boolean NOT NULL
  );
  ```
  

Setup

1. Edit appsettings.json, set your ConnectionStrings:ContatosDb.
2. In a terminal:

   dotnet restore
   dotnet build
   dotnet run --project BackgroundBuilder.csproj
   

3. The main window will appear; on load it fetches and displays all contatos.

Architecture

• MVVM with MVVM with ObservableObject, RelayCommand.
• DI via Microsoft.Extensions.Hosting.
• Repositories (PostgresContatoRepository) handle all DB I/O with Dapper.
• Services (DatabaseService) manage the Npgsql connection.
• ViewModels free of data-access logic: only orchestration.

---

New Background & Export Features

• Select Background…
  Opens a file picker—choose any image (PNG, JPG, BMP). That image becomes your canvas.

• Create Image…
  Saves the current DataGrid overlaid on the background as a single PNG.
  Uses WPF’s RenderTargetBitmap and PngBitmapEncoder under the hood.

---