Xamarin.Forms -使用默认应用程序打开文件

using Xamarin.Forms;

public class FileOpenerPage : ContentPage
{
    public FileOpenerPage()
    {
        Button openButton = new Button
        {
            Text = "Open File",
            VerticalOptions = LayoutOptions.CenterAndExpand,
            HorizontalOptions = LayoutOptions.CenterAndExpand
        };

        openButton.Clicked += async (sender, e) =>
        {
            var fileUrl = new Uri("file:///path/to/your/file.pdf");
            await Device.OpenUri(fileUrl);
        };

        Content = new StackLayout
        {
            Children = { openButton }
        };
    }
}

// iOS 的 Info.plist 中添加以下权限
<key>NSPhotoLibraryUsageDescription</key>
<string>This app requires access to the photo library.</string>

// Android 的 AndroidManifest.xml 中添加以下权限
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>