DocViewer.Android 3.0.8

PdfViewer for .NET Android

A robust .NET for Android binding library for the Pdf-Viewer library. This library provides a feature-rich, customizable PDF viewer component for Xamarin.Android and .NET Android applications.

Features

• Multiple Loading Sources: Load PDFs from URL, File, Assets, or URI.
• Advanced Navigation: Horizontal/Vertical scrolling, Single Page mode, Wrapped mode.
• Page Layout: Spread modes (Odd/Even), Page Snapping, Single Page Arrangement.
• Complete UI System: Includes PdfToolBar, PdfScrollBar, and PdfViewerContainer for a drop-in UI.
• Editor Capabilities: Built-in support for basic annotation actions (Undo/Redo) and property customization.
• Customizable: Extensive API to control visual properties and alignment.
• Zero Warnings: Clean build with no binding warnings.

Installation

Add the PdfViewer.Binding project or DLL to your .NET Android solution.

1. Add PdfViewer.Binding.csproj to your solution.
2. Add a project reference from your App project to PdfViewer.Binding.

Getting Started

1. XML Layout

The library provides a composed UI container PdfViewerContainer that automatically manages the Viewer, Toolbar, and ScrollBar.

<com.bhuvaneshw.pdf.ui.PdfViewerContainer
    android:id="@+id/pdfViewerContainer"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    
    <com.bhuvaneshw.pdf.ui.PdfToolBar
        android:id="@+id/pdfToolBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    
    <com.bhuvaneshw.pdf.PdfViewer
        android:id="@+id/pdfViewer"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    
    <com.bhuvaneshw.pdf.ui.PdfScrollBar
        android:id="@+id/pdfScrollBar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
        
</com.bhuvaneshw.pdf.ui.PdfViewerContainer>

2. Basic Initialization (C#)

In your Activity or Fragment:

using Com.Bhuvaneshw.Pdf;
using Com.Bhuvaneshw.Pdf.UI;

// ... Inside OnCreate

// 1. Find References
var viewer = FindViewById<PdfViewer>(Resource.Id.pdfViewer);
var container = FindViewById<PdfViewerContainer>(Resource.Id.pdfViewerContainer);
var toolbar = FindViewById<PdfToolBar>(Resource.Id.pdfToolBar);
var scrollBar = FindViewById<PdfScrollBar>(Resource.Id.pdfScrollBar);

// 2. Setup Dependencies
toolbar.SetupWith(viewer);
scrollBar.SetupWith(viewer, toolbar, false); // false = force update

// 3. Load PDF
viewer.LoadFromUrl("https://example.com/sample.pdf");
// OR
// viewer.LoadFromAsset("sample.pdf");

detailed API Reference

Loading Content

Configuration Properties

The PdfViewer class exposes several properties to control behavior and appearance.

Scroll Mode (PdfViewer.ScrollMode)

Controls how pages are scrolled.

• PageScrollMode.Horizontal: Standard horizontal scrolling.
• PageScrollMode.Vertical: Standard vertical scrolling (Default).
• PageScrollMode.SinglePage: Displays one page at a time.
• PageScrollMode.Wrapped: Wraps pages like a continuous document.

viewer.ScrollMode = PdfViewer.PageScrollMode.Horizontal;

Spread Mode (PdfViewer.SpreadMode)

Controls page spreads (like a book view).

• PageSpreadMode.None: Single page view (Default).
• PageSpreadMode.Odd: Starts with an odd page.
• PageSpreadMode.Even: Starts with an even page.

viewer.SpreadMode = PdfViewer.PageSpreadMode.Odd;

Align Mode (PdfViewer.AlignMode)

Controls page alignment within the viewport.

• PageAlignMode.Start
• PageAlignMode.CenterHorizontal
• PageAlignMode.CenterVertical
• PageAlignMode.CenterBoth
• etc.

viewer.AlignMode = PdfViewer.PageAlignMode.CenterBoth;

Other Properties

• SnapPage (bool): If true, scrolling snaps to the nearest page edge.
• SinglePageArrangement (bool): Optimized arrangement for single page viewing.
• PageRotation (int): Rotation angle in degrees (0, 90, 180, 270).
• DoubleClickThreshold (long): Time in ms for detecting double clicks.
• LongClickThreshold (long): Time in ms for detecting long clicks.
• ScrollSpeedLimit (float): Max scroll speed multiplier.

PdfToolBar Customization

The PdfToolBar provides built-in navigation and actions.

• Handling Back Button: Because OnBack expects a Kotlin function, use a helper class implementation:

  private class BackAction : Java.Lang.Object, Kotlin.Jvm.Functions.IFunction0 {
      private readonly Activity _act;
      public BackAction(Activity a) => _act = a;
      public Java.Lang.Object Invoke() { _act.Finish(); return null; }
  }
  
  toolbar.OnBack = new BackAction(this);
  

PdfEditor

Access annotation features via the Editor property.

// Undo/Redo
viewer.Editor.Undo();
viewer.Editor.Redo();

// Customization
viewer.Editor.HighlightColor = Android.Graphics.Color.Yellow;
viewer.Editor.InkColor = Android.Graphics.Color.Red;

Requirements

• .NET 10 Android
• Android SDK 23+ (Min SDK)

Build Instructions

cd PdfViewer.Binding
dotnet build