我已经做了一个例子来测试在android的webview，它可以成功地打开在网站中的href。
所以你可以检查你要打开的href是否是http，对于27以上的android api，你需要在AndroidManifest.xml中声明android:usesCleartextTraffic为true，比如：

<manifest ...>
  <application
    ...
    android:usesCleartextTraffic="true"
    ...>
    ...
  </application>
  <uses-permission android:name="android.permission.INTERNET" />
</manifest>

您也可以尝试在您的webview中加载另一个网站进行测试。

编辑

引用这个native android case和这个custom webview handler，你就可以试着用这个句柄重写ShouldOverrideUrlLoading方法来做到这一点。

So to handle redirects to _blank targets in a WebView by keeping them in the same window/view, I had to create a custom renderer, but don't worry, you can just copy-paste the code and it will work perfectly :) .

1. Create a folder called Controls inside Platforms/Android , then create a class file, I called it MltWebViewClientRenderer.cs . Paste this inside the file:

public class MltWebViewRenderer : WebViewRenderer
    {
        public MltWebViewRenderer(Context context) : base(context)
        {
        }
        protected override void OnElementChanged(ElementChangedEventArgs<Microsoft.Maui.Controls.WebView> e)
        {
            base.OnElementChanged(e);
            Control.SetWebViewClient(new MltWebViewClient());
            global::Android.Webkit.WebView.SetWebContentsDebuggingEnabled(true);
        }
    }

    public class MltWebViewClient : global::Android.Webkit.WebViewClient
    {
        public MltWebViewClient()
        {
        }

        public override bool ShouldOverrideUrlLoading(global::Android.Webkit.WebView view, IWebResourceRequest request)
        {
            view.Settings.SetSupportMultipleWindows(false);
            view.Settings.JavaScriptCanOpenWindowsAutomatically = true;
            
            view.Settings.JavaScriptEnabled = true;

            view.SetWebChromeClient(new WebChromeClient());

            return base.ShouldOverrideUrlLoading(view, request);
        }
    }

The above code basically allows access to the Settings of the WebView .

1. In the MauiProgram.cs , you need to add some services to the builder, as such:

var builder = MauiApp.CreateBuilder();
            builder
                .UseMauiApp<App>()
                .ConfigureFonts(fonts =>
                {
                    fonts.AddFont("OpenSans-Regular.ttf", "OpenSansRegular");
                    fonts.AddFont("OpenSans-Semibold.ttf", "OpenSansSemibold");
                })
                .UseMauiCompatibility()
                .ConfigureMauiHandlers(x =>
                {
#if ANDROID
                    x.AddCompatibilityRenderer(typeof(WebView), typeof(Platforms.Android.Controls.MltWebViewRenderer));
#endif
                });
            return builder.Build();

The above only invokes our custom renderer if we are on Android.
Note: This solution only works for Android API versions 24 and above.