Xamarin AndroidX迁移：应用程序启动时崩溃（System.InvalidCastException:AndroidX.AppCompat.Widget.Toolbar）

我最近将我的应用程序更新为Xamarin Forms 5.0，因此更新为AndroidX。我升级了所有软件包，这些软件包仍然引用旧的Android支持库，并将代码中出现的所有Android支持库引用替换为来自AndroidX的等效引用

但我的应用程序在启动时不断崩溃，以下情况除外：

[AndroidRuntime] android.runtime.JavaProxyThrowable: System.InvalidCastException: Unable to convert instance of type 'Android.Widget.LinearLayout' to type 'AndroidX.AppCompat.Widget.Toolbar'.
[AndroidRuntime]   at Java.Interop.JavaObjectExtensions.CastClass (Android.Runtime.IJavaObject instance, System.Type resultType) [0x0005d] in <1410c4afb1fd4823a12ecf897dd92287>:0 
[AndroidRuntime]   at Java.Interop.JavaObjectExtensions._JavaCast[TResult] (Android.Runtime.IJavaObject instance) [0x00052] in <1410c4afb1fd4823a12ecf897dd92287>:0 
[AndroidRuntime]   at Java.Interop.JavaObjectExtensions.JavaCast[TResult] (Android.Runtime.IJavaObject instance) [0x00000] in <1410c4afb1fd4823a12ecf897dd92287>:0 
[AndroidRuntime]   at Android.Runtime.Extensions.JavaCast[TResult] (Android.Runtime.IJavaObject instance) [0x00000] in <1410c4afb1fd4823a12ecf897dd92287>:0 
[AndroidRuntime]   at Xamarin.Forms.Platform.Android.FormsAppCompatActivity.OnCreate (Android.OS.Bundle savedInstanceState, Xamarin.Forms.Platform.Android.ActivationFlags flags) [0x00090] in <04c545f414d24a37af95d995791bb9a9>:0 
[AndroidRuntime]   at Xamarin.Forms.Platform.Android.FormsAppCompatActivity.OnCreate (Android.OS.Bundle savedInstanceState) [0x00000] in <04c545f414d24a37af95d995791bb9a9>:0 
[AndroidRuntime]   at MyAppDemo.Droid.MainActivity.OnCreate (Android.OS.Bundle savedInstanceState) [0x00000] in <bdc0728e30d74980ad82869dc2b7bae4>:0 
[AndroidRuntime]   at Android.App.Activity.n_OnCreate_Landroid_os_Bundle_ (System.IntPtr jnienv, System.IntPtr native__this, System.IntPtr native_savedInstanceState) [0x0000f] in <1410c4afb1fd4823a12ecf897dd92287>:0 
[AndroidRuntime]   at (wrapper dynamic-method) Android.Runtime.DynamicMethodNameCounter.3(intptr,intptr,intptr)
[AndroidRuntime]    at crc648c69828764ca3d7c.MainActivity.n_onCreate(Native Method)
[AndroidRuntime]    at crc648c69828764ca3d7c.MainActivity.onCreate(MainActivity.java:43)
[AndroidRuntime]    at android.app.Activity.performCreate(Activity.java:8000)
[AndroidRuntime]    at android.app.Activity.performCreate(Activity.java:7984)
[AndroidRuntime]    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
[AndroidRuntime]    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3404)
[AndroidRuntime]    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3595)
[AndroidRuntime]    at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
[AndroidRuntime]    at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
[AndroidRuntime]    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
[AndroidRuntime]    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
[AndroidRuntime]    at android.os.Handler.dispatchMessage(Handler.java:106)
[AndroidRuntime]    at android.os.Looper.loop(Looper.java:223)
[AndroidRuntime]    at android.app.ActivityThread.main(ActivityThread.java:7660)
[AndroidRuntime]    at java.lang.reflect.Method.invoke(Native Method)
[AndroidRuntime]    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
[AndroidRuntime]    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)

这是我的工具栏（在

Resources>layout>toolbar.axml下）：


当我使用Xamarin时，我也遇到了同样的问题，对我来说，它有助于更改下的链接属性

-->Project.android->Properies->Anroid选项->链接

切换到无，尝试启动项目，然后切换回sdk和用户程序集

这一个为我做了
解决方案：删除工具栏。axml将修复此错误。
嗯，不幸的是，这对我来说没有任何改变。。还是一样的行为
androidx.appcompat.widget.Toolbar
是Toolbar的最新版本。您是否尝试删除此文件？或者在MainActivity中对工具栏资源进行注释？删除整个
toolbar.axml
文件对我来说很有效。似乎不再需要了。谢谢！很乐意帮忙。我在答复中反对这种解决办法。别忘了接受它作为答案。谢谢~
[Activity(ResizeableActivity = true, Label = “My App”, Icon = "@drawable/ic_launcher", MainLauncher = false, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation, Theme = "@style/MyTheme", LaunchMode = LaunchMode.SingleTop)]
public class MainActivity : Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);

        ToolbarResource = Resource.Layout.toolbar;
        TabLayoutResource = Resource.Layout.tabs;
        
        ...
    }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.Toolbar      // <- before replacing: android.support.v7.widget.Toolbar
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:minHeight="?attr/actionBarSize"
    android:background="?attr/colorPrimary"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
    app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
    app:layout_scrollFlags="scroll|enterAlways" />