# Quick Start

## Content

The following example demonstrates loading a PDF document in FlexViewer.

### **Required namespaces**

```auto
using C1.Document;
using C1.Maui.Viewer;
using C1.Report;
using System.Net;
```

### Load a PDF Document

**C#**

```auto
var source = new C1PdfDocumentSource();source.LoadFromFile(@"D:\FlexViewer\DefaultDocument.pdf");
flexViewer.DocumentSource = source;
```

>type=note
> Note: `LoadFromFile` is synchronous and processes the PDF on the calling thread. For large documents or low-memory devices, run the operation on a background thread to keep the UI responsive.


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