Simple cross-platform plug-in that allows you to pick files and work with them.

The original project can be found here, but seems abandoned, this one was forked and further developed.

NuGet: https://www.nuget.org/packages/Xamarin.Plugin.FilePicker/

Add this as a source to your IDE to find the latest packages: https://ci.appveyor.com/nuget/filepicker-plugin-for-xamarin

• Install into your Xamarin.Android, Xamarin.iOS, Xamarin.Forms, Xamarin.Mac project and Client projects.

Platform Support

* The Xamarin.Mac implementation has only been tested on MacOS 10.12.

Call CrossFilePicker.Current from any platform or .NET Standard project to gain access to APIs.

        try
        {
            FileData fileData = await CrossFilePicker.Current.PickFile();
            if (fileData == null)
                return; // user canceled file picking

            string fileName = fileData.FileName;
            string contents = System.Text.Encoding.UTF8.GetString(fileData.DataArray);

            System.Console.WriteLine("File name chosen: " + fileName);
            System.Console.WriteLine("File data: " + contents);
        }
        catch (Exception ex)
        {
            System.Console.WriteLine("Exception choosing file: " + ex.ToString());
        }

Starts file picking and returns file data for picked file. File types can be specified in order to limit files that can be selected. Note that this method may throw exceptions that occured during file picking.

Parameter allowedTypes: Specifies one or multiple allowed types. When null, all file types can be selected while picking.

On Android you can specify one or more MIME types, e.g. "image/png"; also wild card characters can be used, e.g. "image/*".

On iOS you can specify UTType constants, e.g. UTType.Image.

The returned FileData object contains multiple properties that can be accessed:

public class FileData
{
    /// When accessed, reads all data from the picked file and returns it.
    public byte[] DataArray { get; }

    /// Filename of the picked file; doesn't contain any path.
    public string FileName { get; }

    /// Full file path of the picked file; note that on some platforms the
    /// file path may not be a real, accessible path but may contain an
    /// platform specific URI; may also be null.
    public string FilePath { get; }

    /// Returns a stream to the picked file; this is the most reliable way
    /// to access the data of the picked file.
    public Stream GetStream();
}

Note that DataArray is filled on first access, so be sure to rewind the stream when you access it via GetStream() afterwards.

Android: The WRITE_EXTERNAL_STORAGE & READ_EXTERNAL_STORAGE permissions are required.

Starting from Android 6.0 (Marshmallow) you have to request the permission from the user. This can be done using ActivityCompat.RequestPermission() or you can use the Xamarin.Plugin.Permission plugin. See also code in the sample project: https://github.com/jfversluis/FilePicker-Plugin-for-Xamarin-and-Windows/blob/develop/samples/Plugin.FilePicker.Sample.Forms/Forms/MainPage.xaml.cs

iOS: Need Configure iCloud Driver for your app

InvalidOperationException "Only one operation can be active at a time"

This occurs when PickFile() is called multiple times and the task being awaited didn't return or throws an exception that wasn't caught. Be sure to catch any exceptions and handle them appropriately. See the example code above.

Exception "This functionality is not implemented in the portable version of this assembly. You should reference the NuGet package from your main application project in order to reference the platform-specific implementation."

This occurs when you are using the old-style NuGet references (not the PackageReference mechanism) and you forgot to add the NuGet package to the Android package. When using PackageReference this is not necessary anymore because the bait-and-switch assemblies of FilePicker are correctly resolved.

InvalidOperationException "Android permission READ_EXTERNAL_STORAGE is missing or was denied by user"

Starting from Android 6.0 (Marshmallow) permissions must be added to the AndroidManifest.xml (as before) but the permission must be requested and granted by the user at runtime as well. When the user denied the permission, don't call PickFile(). Check out the sample project in the github repository for an example how to check for permission.

Picked file path is invalid, file doesn't exist

On iOS the plugin uses UIDocumentPickerViewController and specifies the mode UIDocumentPickerMode.Import. After picking is done, iOS copies the picked file to the app's "Inbox" folder where it can be accessed. iOS also cleans up the temporary inbox folder regularly. After picking the file you have to either copy the file to another folder or access the data by getting the property DataBytes or opening a stream to the file by calling GetStream().

• jfversluis
• rafaelrmou (original author)
• vividos

Thanks!

MIT Licence