Download files in MAUI Android WebView

For the android, you can try to add a DownloadListener to the webview. I have testd it and the file can download successfully.

Create the custom downloadlistener class in the \Platforms\Android:

public class MyDownLoadListener : Java.Lang.Object, IDownloadListener
{
    public void OnDownloadStart(string url, string userAgent, string contentDisposition, string mimetype, long contentLength)
    {
        var manager = (DownloadManager)Microsoft.Maui.ApplicationModel.Platform.CurrentActivity.GetSystemService(global::Android.App.Application.DownloadService);
        var uri = global::Android.Net.Uri.Parse(url);
        DownloadManager.Request downloadrequest = new DownloadManager.Request(uri);
        downloadrequest.SetNotificationVisibility(DownloadVisibility.VisibleNotifyCompleted);
        manager.Enqueue(downloadrequest);
    }
}

In the page's xaml:

<WebView x:Name="webview" Source="https://www.myfreemp3.com.cn/" HeightRequest="500"/>

And set the listener for the webview in the Page.cs:

protected override void OnHandlerChanged()
{
    base.OnHandlerChanged();
#if ANDROID
    (webview.Handler.PlatformView as Android.Webkit.WebView).SetDownloadListener(new Platforms.Android.MyDownLoadListener());
    (webview.Handler.PlatformView as Android.Webkit.WebView).Settings.JavaScriptEnabled = true;
    (webview.Handler.PlatformView as Android.Webkit.WebView).Settings.DomStorageEnabled = true;
#endif
}