Skip to content

Latest commit

 

History

History

foxit_xamarin_android

README.md

Implement Foxit PDF SDK for Android using Xamarin/.NET

Welcome to foxit. This guide will show you how to integrate Foxit PDF SDK for Android into your Xamarin.Android/.NET Android application.

Prerequisites

  • Visual Studio
    Foxit PDF SDK Version >= 8.4.0: Visual Studio 2022 and above
    Foxit PDF SDK Version < 8.4.0: Visual Studio 2019 and above
  • TargetFrameworkVersion >= Android 10.0
    screenshot14
  • Minimum Android Version: API 19 (Android4.4)
  • JDK Version >= 1.8

Integrate Foxit PDF SDK into your Xamarin project

There are two ways to integrate Foxit PDF SDK into your Xamarin project:

  • Install By NuGet

  • Integrate manually by building and referencing DLLs

    Install By NuGet

    It is now possible to integrate Foxit PDF SDK into your Xamarin project through NuGet packages, which is much easier than the second way Integrate manually by building and referencing DLLs , and can save you much time.

    To integrate Foxit PDF SDK into your Xamarin project through Nuget packages, please follow the steps below:

    • In the Solution Explorer, right-click the References node of your project, and click Manage NuGet Packages…

      screenshot1

    • Then select the Browse tab, search for Foxit.Android, Foxit.Android.UIExtensions and install them.

      screenshot2

    • Get key. If you do not already have a valid Foxit license key, please download foxitpdfsdk_(version_no)_android.zip from https://developers.foxitsoftware.com/pdf-sdk/android/ to get the key.

    After finishing the above steps, the References of your project will look like:
    screenshot3

    Integrate manually by building and referencing DLLs

    To integrate manually, you should first build DLLs, and then add it as a reference to your project.

    • Download or Clone Foxit PDF SDK for Android, then copy the following files (libraries and licenses) in the libs folder of the extracted package to foxit_xamarin_android\libs directory:

      FoxitRDK.aar
      FoxitRDKUIExtensions.aar
      rdk_key.txt
      rdk_sn.txt

    • Build DLLs
      You need to manually compile to get the following dll：

      FoxitRDK.dll
      MSAL.dll
      MSCommon.dll
      RMSSDK.dll
      RMSSDK_UI.dll
      XCrash.dll
      FoxitUIExtensions.dll
      RxAndroid.dll
      Cropper.dll

      Compilation steps：
      Step1: Load FoxitUIExtensions.sln in Visual Studio 2019 under the foxit_xamarin_android\FoxitUIExtensions directory.
      Step2: Right-click FoxitUIExtensions project, click Build/Rebuild .
      Step3: If build is successful, the
      FoxitRDK.dll
      MSAL.dll
      MSCommon.dll
      RMSSDK.dll
      RMSSDK_UI.dll
      XCrash.dll
      will be generated in foxit_xamarin_android\FoxitRDK\FoxitRDK\bin\Debug (or release)directory.

      the
      FoxitRDKUIExtensions.dll
      RxAndroid.dll
      Cropper.dll
      will be generated in foxit_xamarin_android\FoxitUIExtensions\FoxitUIExtensions\bin\Debug (or release)directory.

    • Add the built DLLs as references to your project
      This section takes FoxitRDK.dll as an example to show you how to add it as a reference to your project. For other DLLs, do the same steps with FoxitRDK.dll. We assume that you have got the FoxitRDK.dll, if not, please refer to Build DLLs section to build the FoxitRDK project and generate the FoxitRDK.dll.

      • In the Solution Explorer, right-click the References node of your project and select Add Reference…

        screenshot4

      • In the Reference Manager dialog, click Browse… to find the FoxitRDK.dll (in the foxit_xamarin_android\FoxitRDK\FoxitRDK\bin\Debug (or release) folder), select it and then click Add:

        screenshot5
        screenshot6

        Then, the FoxitRDK.dll will appear in the list and has already been checked. Click OK:

        screenshot7

    • Add the following dll to you demo refer to the steps of adding FoxitRDK.dll.

      MSAL.dll
      MSCommon.dll
      RMSSDK.dll
      RMSSDK_UI.dll
      XCrash.dll
      FoxitUIExtensions.dll
      RxAndroid.dll
      Cropper.dll

    • Note:
      If you integrate manually by building dlls, you must manually install the following dependencies.
      Xamarin.AndroidX.Browser Xamarin.Google.Android.Material Xamarin.AndroidX.AppCompat Xamarin.AndroidX.Legacy.Support.V4 Xamarin.AndroidX.Lifecycle.LiveData Xamarin.AndroidX.ConstraintLayout (It's required for opening a RMS protected PDF file)

    After finishing the above steps, the References of your project will look like:
    screenshot8

Integrate Foxit PDF SDK into your .Net project

Similar to Xamarin, but the referencing DLLs method is more complex and .NET does not recommend using it. We recommend using nupkg, please refer to Integrate with NuGet.

Build a Xamarin/.NET Android project using Foxit PDF SDK for Android

This section will help you to quickly build a full-featured PDF Reader in Xamarin Android platform with step-by-step instructions provided.

1. Create a new Xamarin Android project

Open Visual Studio 2019, choose File -> New -> Project… to start the New Project. Let's take TestXamarin as an example .Create a new Xamarin Android project called TestXamarin ,Then click OK:

screenshot9

In the New Android App dialog, select Single View App,Then, click OK:

screenshot10

2. Integrate Foxit PDF SDK into the project

Please refer to Integrate Foxit PDF SDK into your Xamarin project to integrate the Foxit PDF SDK into the created project. We recommend using the first way Integrate with NuGet, which is more easy and convenient.

3. Initialize Foxit PDF SDK Library

Before calling any APIs, you must first initialize Foxit PDF SDK library by using the function Library.Initialize(sn, key). Below you can see an example of how to initialize the SDK library. The next section will show you where to include this code in MainActivity.cs file:

using Com.Foxit.Sdk;
using Com.Foxit.Sdk.Common;
...
String sn = "xxx";
String key = "xxx";
int errCode = Library.Initialize(sn, key);
if (errCode != Constants.EErrSuccess)
return;

Note: The value of sn can be found in the rdk_sn.txt (the string after SN=) and the value of key can be found in the rdk_key.txt (the string after Sign=). The trial license files (rdk_sn.txt and rdk_key.txt) can be found in the foxit_xamarin_android\libs folder or in the libs folder of Foxit PDF SDK for Android package

4. Display a PDF document using PDFViewCtrl

To display a PDF document, please follow the steps below:

1) Instantiate a PDFViewCtrl object to show an existing document.
In MainActivity.cs file, instantiate a PDFViewCtrl object, and call PDFViewCtrl#OpenDoc function to open and render the PDF document:

using Com.Foxit.Sdk;
...
private String path = "/mnt/sdcard/complete_pdf_viewer_guide_android.pdf";
private PDFViewCtrl pdfViewCtrl;
...
// Instantiate a PDFViewCtrl object.
pdfViewCtrl = new PDFViewCtrl(this.ApplicationContext);
// Open and Render a PDF document.
pdfViewCtrl.OpenDoc(path, null);
SetContentView(pdfViewCtrl);

Note: Please make sure you have pushed the complete_pdf_viewer_guide_android.pdf document into the SD card of the Android device or emulator that will be used to run this project. Certainly, you can change the file path with your own files.

Update MainActivity.cs as follows:

using System;
using Android.App;
using Android.OS;
using AndroidX.AppCompat.App;
using Com.Foxit.Sdk;
using Com.Foxit.Sdk.Common;
namespace TestXamarin
{
[Activity(Label = "@string/app_name", Theme = "@style/AppTheme.NoActionBar",MainLauncher = true)]
    public class MainActivity : AppCompatActivity
    {
        // The value of "sn" can be found in the "rdk_sn.txt".
        // The value of "key" can be found in the "rdk_key.txt".
        private String sn = "xxx";
        private String key = "xxx";
        private String path = "/mnt/sdcard/complete_pdf_viewer_guide_android.pdf";
        private PDFViewCtrl pdfViewCtrl;
        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
               // Initialize Foxit SDK Library.
               int errCode = Library.Initialize(sn, key);
               if (errCode != Constants.EErrSuccess)
                   return;
               // Instantiate a PDFViewCtrl object.
               pdfViewCtrl = new PDFViewCtrl(this.ApplicationContext);
               // Open and Render a PDF document.
               pdfViewCtrl.OpenDoc(path, null);
               SetContentView(pdfViewCtrl);
        }
    }
}

2) Set permissions to write and read the SD card of the Android devices or emulators
Note: If you want to run this project on an Android 6.0 (API 23) or higher devices/emulators, you can do one of the following:

  • a) Change the android:targetSdkVersion in "AndroidManifest.xml" to a lower SDK version that is less than 23, such as 21

  • b) Write additional code to require the authorization of runtime permissions.

  • a) Change the android:targetSdkVersion in AndroidManifest.xml

    In this case, set the users-permission in the AndroidManifest.xml found in the TestXamarin\Properties to give the project permission to write and read the SD card of the Android devices or emulators:
    screenshot11

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
  • b) Write additional code to require the authorization of runtime permissions.
    In the MainActivity.cs file, add code to require the authorization of runtime permissions.
    So, update the whole MainActivity.cs as follows:
   using System;
   using Android.App;
   using Android.OS;
   using Android.Runtime;
   using AndroidX.AppCompat.App;
   using Com.Foxit.Sdk;
   using Com.Foxit.Sdk.Common;
   using Android;
   using Android.Content.PM;
   using AndroidX.Core.Content;
   using AndroidX.Core.App;
   namespace TestXamarin
   {
   [Activity(Label = "@string/app_name", Theme = "@style/AppTheme.NoActionBar",MainLauncher = true)]
       public class MainActivity : AppCompatActivity
       {
           public static int REQUEST_EXTERNAL_STORAGE = 1;
           private static string[] PERMISSIONS_STORAGE = {
                   Manifest.Permission.ReadExternalStorage,
                   Manifest.Permission.WriteExternalStorage
           };
          // The value of "sn" can be found in the "rdk_sn.txt".
          // The value of "key" can be found in the "rdk_key.txt".
           private String sn = "xxx";
           private String key = "xxx";
           private String path = "/mnt/sdcard/complete_pdf_viewer_guide_android.pdf";
           private PDFViewCtrl pdfViewCtrl;
           protected override void OnCreate(Bundle savedInstanceState)
           {
               base.OnCreate(savedInstanceState);
               // Initialize Foxit SDK Library.
               int errCode = Library.Initialize(sn, key);
               if (errCode != Constants.EErrSuccess)
                   return;
               // Instantiate a PDFViewCtrl object.
               pdfViewCtrl = new PDFViewCtrl(this.ApplicationContext);
               // Require the authorization of runtime permissions.
               if (Build.VERSION.SdkInt > BuildVersionCodes.M)
               {
                   Permission permission =
                           ContextCompat.CheckSelfPermission(this.ApplicationContext,
                                   Manifest.Permission.WriteExternalStorage);
                   if (permission != Permission.Granted)
                   {
                       ActivityCompat.RequestPermissions(this, PERMISSIONS_STORAGE,
                               REQUEST_EXTERNAL_STORAGE);
                       return;
                   }
               }
               // Open and Render a PDF document.
               pdfViewCtrl.OpenDoc(path, null);
               SetContentView(pdfViewCtrl);
           }
           public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Permission[] grantResults)
           {
               if (requestCode == REQUEST_EXTERNAL_STORAGE
                       && grantResults[0] == Permission.Granted)
               {
                   if (pdfViewCtrl != null)
                   {
                       pdfViewCtrl.OpenDoc(path, null);
                   }
               }
               else
               {
                   base.OnRequestPermissionsResult(requestCode, permissions,
                           grantResults);
               }
           }
       }
   }

3) Enable Multi-Dex. If you don't, you may encounter the problem "error MSB6006: "java.exe" exited with code 2.
Right-click the Properties node of TestXamarin project, find Android Options then check Enable Multi-Dex and set Dex compiler to d8:

screenshot16

In this chapter, we build and run the project on an AVD targeting 9.0 (API 28), and use the second method (require authorization of runtime permissions) to get the permissions to write and read the SD card of the emulator.

After building the project and installing APK on the emulator, tap Allow on the pop-up window to allow the project to access files on the device, and then you will see that the complete_pdf_viewer_guide_android.pdf document is displayed . Now, this sample app has some basic PDF features, such as zooming in/out and page turning.

screenshot13

How to run the complete_pdf_viewer

1: Download foxitpdfsdk_(version_no)_android.zip from https://developers.foxitsoftware.com/pdf-sdk/android/, then unzip the foxitpdfsdk_(version_no)_android.zip, and enter the libs directory,copy the following files into the foxit_xamarin_android/libs directory:

  • rdk_key.txt
  • rdk_sn.txt

2:
2.1: Xamarin Demo Run the FoxitRDKDemo.Xamarin\complete_pdf_viewer.sln project in the simulator or on a physical device.
2.2: .NET Demo Run the FoxitRDKDemo.Net\complete_pdf_viewer.sln project in the simulator or on a physical device.

Xamarin Demo

Please refer to FoxitRDKDemo.Xamarin\complete_pdf_viewer.sln project.

.NET Demo

Please refer to FoxitRDKDemo.Net\complete_pdf_viewer.sln project.

Issues

1: java.lang.OutOfMemoryError. Consider increasing the value of $(JavaMaximumHeapSize)

Solution：Right-click the Properties node of your project, and open it. Find Android Options and click Advanced button find Java Max Heap Size set it to 2G. As show below:

screenshot15

2: invalid opcode ba - invokedynamic requires --min-sdk-version >= 26 (currently 13), Cannot fit requested classes in a single dex file (# methods: 87605 > 65536)

Solution：Right-click the Properties node of your project, and open it. Find Android Options and check Enable Multi-Dex and set Dex compiler to d8. As show below:

screenshot16

3: Attribute application@theme value=(@style/AppTheme) from AndroidManifest.xml is also present at AndroidManifest.xml value=(@style/fx_app_theme).

Suggestion: add 'tools:replace="android:theme"' to element at AndroidManifest.xml.

  <manifest xmlns:android="http://schemas.android.com/apk/res/android"
+             xmlns:tools="http://schemas.android.com/tools"
             ...>
  
     ...
     ...
  
      <application
          ...
+          tools:replace="android:theme">
          ...
      </application>
  </manifest>

More

For more usage of xamarin, you can refer to foxitpdfsdk_(version_no)_android\docs\developer_guide_android.pdf the section 9.3 . the foxitpdfsdk_(version_no)_android.zip can download from https://developers.foxitsoftware.com/pdf-sdk/android/

License

lisense for Cropper

https://github.com/edmodo/cropper

Copyright 2013, Edmodo, Inc.

Licensed under the Apache License, Version 2.0 (the "License"); you may not  
use this work except in compliance with the License. You may obtain a copy  
of the License in the LICENSE file, or at:
  
http://www.apache.org/licenses/LICENSE-2.0  
  
Unless required by applicable law or agreed to in writing, software   
distributed under the License is distributed on an "AS IS" BASIS, WITHOUT   
WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the   
License for the specific language governing permissions and limitations   
under the License.

lisense for ADAL

https://github.com/AzureAD/azure-activedirectory-library-for-android

Copyright (c) Microsoft Corporation.

All rights reserved. This code is licensed under the MIT License.
  
We Value and Adhere to the Microsoft Open Source Code of Conduct  
   
This project has adopted the Microsoft Open Source Code of Conduct. For   
more information see the Code of Conduct FAQ or contact opencode@microsoft  
.com with any additional questions or comments.

lisense for GSON

https://github.com/google/gson

Copyright 2008 Google Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at  
  
  http://www.apache.org/licenses/LICENSE-2.0  
  
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

lisense for RxAndroid

https://github.com/ReactiveX/RxAndroid

Copyright 2015 The RxAndroid authors

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

lisense for Xcrash

https://github.com/iqiyi/xCrash

xCrash is MIT licensed, as found in the LICENSE file.

xCrash documentation is Creative Commons licensed, as found in the LICENSE-docs file.