领域 Xamarin - GetInstance() 上的错误答案

【问题标题】：Realm Xamarin - Error on GetInstance()领域 Xamarin - GetInstance() 上的错误
【发布时间】：2016-10-16 15:16:03
【问题描述】：

我这样设置我的主页：

namespace MyNamepage
{
public partial class MyPage: ContentPage
  {
    private Realm realm;
    public MyPage()
    {
        InitializeComponent();
        this.realm = Realm.GetInstance();
    }
  }
}

调试 Android 项目时出现此错误并且应用程序崩溃：

System.Reflection.TargetInvocationException：已抛出异常通过调用的目标。

我已经使用 NuGet 在 PCL 和 Droid Project 中安装了“Realm”，但它似乎不起作用。
如果我删除 GetInstance() 调用，应用程序不会崩溃；

堆栈跟踪：

10-17 10:36:31.935 I/MonoDroid(31518): UNHANDLED EXCEPTION:
10-17 10:36:31.955 I/MonoDroid(31518): System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.PlatformNotSupportedException: The PCL build of Realm is being linked which probably means you need to use NuGet or otherwise link a platform-specific Realm.dll to your main application.
10-17 10:36:31.955 I/MonoDroid(31518):   at Realms.RealmPCLHelpers.ThrowProxyShouldNeverBeUsed () [0x00000] in <filename unknown>:0
10-17 10:36:31.955 I/MonoDroid(31518):   at Realms.Realm.GetInstance (Realms.RealmConfiguration config) [0x00000] in <filename unknown>:0
10-17 10:36:31.955 I/MonoDroid(31518):   at MyPack.SidePage.MyPage..ctor () [0x00008] in C:\Users\User\documents\visual studio 2015\Projects\MyPack\MyPack\MyPack\SidePage\MyPage.xaml.cs:14
10-17 10:36:31.955 I/MonoDroid(31518):   at (wrapper managed-to-native) System.Reflection.MonoCMethod:InternalInvoke (System.Reflection.MonoCMethod,object,object[],System.Exception&)
10-17 10:36:31.955 I/MonoDroid(31518):   at System.Reflection.MonoCMethod.InternalInvoke (System.Object obj, System.Object[] parameters) [0x00002] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/mcs/class/corlib/System.Reflection/MonoMethod.cs:644
10-17 10:36:31.965 I/MonoDroid(31518):   --- End of inner exception stack trace ---
10-17 10:36:31.965 I/MonoDroid(31518):   at System.Reflection.MonoCMethod.InternalInvoke (System.Object obj, System.Object[] parameters) [0x00016] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/mcs/class/corlib/System.Reflection/MonoMethod.cs:650
10-17 10:36:31.965 I/MonoDroid(31518):   at System.RuntimeType.CreateInstanceMono (Boolean nonPublic) [0x000ca] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/mcs/class/corlib/ReferenceSources/RuntimeType.cs:115
10-17 10:36:31.965 I/MonoDroid(31518):   at System.RuntimeType.CreateInstanceSlow (Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, System.Threading.StackCrawlMark& stackMark) [0x0001a] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/mcs/class/corlib/ReferenceSources/RuntimeType.cs:89
10-17 10:36:31.965 I/MonoDroid(31518):   at System.RuntimeType.CreateInstanceDefaultCtor (Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, System.Threading.StackCrawlMark& stackMark) [0x0002a] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/external/referencesource/mscorlib/system/rttype.cs:5599
10-17 10:36:31.965 I/MonoDroid(31518):   at System.Activator.CreateInstance (System.Type type, Boolean nonPublic) [0x00040] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/external/referencesource/mscorlib/system/activator.cs:201
10-17 10:36:31.965 I/MonoDroid(31518):   at System.Activator.CreateInstance (System.Type type) [0x00000] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/external/referencesource/mscorlib/system/activator.cs:134
10-17 10:36:31.965 I/MonoDroid(31518):   at MyPack.MainPage.OnItemSelected (System.Object sender, Xamarin.Forms.SelectedItemChangedEventArgs e) [0x00016] in C:\Users\User\documents\visual studio 2015\Projects\MyPack\MyPack\MyPack\MainPage.xaml.cs:24
10-17 10:36:31.965 I/MonoDroid(31518):   at (wrapper delegate-invoke) System.EventHandler`1[Xamarin.Forms.SelectedItemChangedEventArgs]:invoke_void_object_TEventArgs (object,Xamarin.Forms.SelectedItemChangedEventArgs)
10-17 10:36:31.975 I/MonoDroid(31518):   at Xamarin.Forms.ListView.OnSelectedItemChanged (Xamarin.Forms.BindableObject bindable, System.Object oldValue, System.Object newValue) [0x0001c] in <filename unknown>:0
10-17 10:36:31.975 I/MonoDroid(31518):   at Xamarin.Forms.BindableObject.SetValueActual (Xamarin.Forms.BindableProperty property, Xamarin.Forms.BindablePropertyContext context, System.Object value, Boolean currentlyApplying, SetValueFlags attributes, Boolean silent) [0x0010e] in <filename unknown>:0
10-17 10:36:31.975 I/MonoDroid(31518):   at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, SetValueFlags attributes, SetValuePrivateFlags privateAttributes) [0x0014b] in <filename unknown>:0
10-17 10:36:31.975 I/MonoDroid(31518):   at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, SetValueFlags attributes) [0x00000] in <filename unknown>:0
10-17 10:36:31.975 I/MonoDroid(31518):   at Xamarin.Forms.ListView.NotifyRowTapped (Int32 groupIndex, Int32 inGroupIndex, Xamarin.Forms.Cell cell) [0x0004c] in <filename unknown>:0
10-17 10:36:31.975 I/MonoDroid(31518):   at Xamarin.Forms.ListView.NotifyRowTapped (Int32 index, Xamarin.Forms.Cell cell) [0x00023] in <filename unknown>:0
10-17 10:36:31.975 I/MonoDroid(31518):   at Xamarin.Forms.Platform.Android.ListViewAdapter.HandleItemClick (Android.Widget.AdapterView parent, Android.Views.View view, Int32 position, Int64 id) [0x00056] in <filename unknown>:0
10-17 10:36:31.975 I/MonoDroid(31518):   at Xamarin.Forms.Platform.Android.CellAdapter.OnItemClick (Android.Widget.AdapterView parent, Android.Views.View view, Int32 position, Int64 id) [0x0002e] in <filename unknown>:0
10-17 10:36:31.975 I/MonoDroid(31518):   at Android.Widget.AdapterView+IOnItemClickListenerInvoker.n_OnItemClick_Landroid_widget_AdapterView_Landroid_view_View_IJ (IntPtr jnienv, IntPtr native__this, IntPtr native_parent, IntPtr native_view, Int32 position, Int64 id) [0x00019] in /Users/builder/data/lanes/3415/7db2aac3/source/monodroid/src/Mono.Android/platforms/android-23/src/generated/Android.Widget.AdapterView.cs:215
10-17 10:36:31.975 I/MonoDroid(31518):   at (wrapper dynamic-method) System.Object:585983a8-79f2-48a3-ac33-5b4c905219f1 (intptr,intptr,intptr,intptr,int,long)
10-17 10:36:31.995 D/Mono    (31518): DllImport searching in: '__Internal' ('(null)').
10-17 10:36:31.995 D/Mono    (31518): Searching for 'java_interop_jnienv_throw'.
10-17 10:36:31.995 D/Mono    (31518): Probing 'java_interop_jnienv_throw'.
10-17 10:36:31.995 D/Mono    (31518): Found as 'java_interop_jnienv_throw'.
An unhandled exception occured.

10-17 10:36:34.115 E/mono    (31518):
10-17 10:36:34.115 E/mono    (31518): Unhandled Exception:
10-17 10:36:34.115 E/mono    (31518): System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.PlatformNotSupportedException: The PCL build of Realm is being linked which probably means you need to use NuGet or otherwise link a platform-specific Realm.dll to your main application.
10-17 10:36:34.115 E/mono    (31518):   at Realms.RealmPCLHelpers.ThrowProxyShouldNeverBeUsed () [0x00000] in <filename unknown>:0
10-17 10:36:34.115 E/mono    (31518):   at Realms.Realm.GetInstance (Realms.RealmConfiguration config) [0x00000] in <filename unknown>:0
10-17 10:36:34.115 E/mono    (31518):   at MyPack.SidePage.MyPage..ctor () [0x00008] in C:\Users\User\documents\visual studio 2015\Projects\MyPack\MyPack\MyPack\SidePage\MyPage.xaml.cs:14
10-17 10:36:34.115 E/mono    (31518):   at (wrapper managed-to-native) System.Reflection.MonoCMethod:InternalInvoke (System.Reflection.MonoCMethod,object,object[],System.Exception&)
10-17 10:36:34.115 E/mono    (31518):   at System.Reflection.MonoCMethod.InternalInvoke (System.Object obj, System.Object[] parameters) [0x00002] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/mcs/class/corlib/System.Reflection/MonoMethod.cs:644
10-17 10:36:34.115 E/mono    (31518):   --- End of inner exception stack trace ---
10-17 10:36:34.115 E/mono    (31518):   at (wrapper dynamic-method) System.Object:585983a8-79f2-48a3-ac33-5b4c905219f1 (intptr,intptr,intptr,intptr,int,long)
10-17 10:36:34.115 E/mono    (31518):   at (wrapper native-to-managed) System.Object:585983a8-79f2-48a3-ac33-5b4c905219f1 (intptr,intptr,intptr,intptr,int,long)
10-17 10:36:34.115 E/mono-rt (31518): [ERROR] FATAL UNHANDLED EXCEPTION: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.PlatformNotSupportedException: The PCL build of Realm is being linked which probably means you need to use NuGet or otherwise link a platform-specific Realm.dll to your main application.
10-17 10:36:34.115 E/mono-rt (31518):   at Realms.RealmPCLHelpers.ThrowProxyShouldNeverBeUsed () [0x00000] in <filename unknown>:0
10-17 10:36:34.115 E/mono-rt (31518):   at Realms.Realm.GetInstance (Realms.RealmConfiguration config) [0x00000] in <filename unknown>:0
10-17 10:36:34.115 E/mono-rt (31518):   at MyPack.SidePage.MyPage..ctor () [0x00008] in C:\Users\User\documents\visual studio 2015\Projects\MyPack\MyPack\MyPack\SidePage\MyPage.xaml.cs:14
10-17 10:36:34.115 E/mono-rt (31518):   at (wrapper managed-to-native) System.Reflection.MonoCMethod:InternalInvoke (System.Reflection.MonoCMethod,object,object[],System.Exception&)
10-17 10:36:34.115 E/mono-rt (31518):   at System.Reflection.MonoCMethod.InternalInvoke (System.Object obj, System.Object[] parameters) [0x00002] in /Users/builder/data/lanes/3415/7db2aac3/source/mono/mcs/class/corlib/System.Reflection/MonoMethod.cs:644
10-17 10:36:34.115 E/mono-rt (31518):   --- End of inner exception stack trace ---
10-17 10:36:34.115 E/mono-rt (31518):   at (wrapper dynamic-method) System.Object:585983a8-79f2-48a3-ac33-5b4c905219f1 (intptr,intptr,intptr,intptr,int,long)
10-17 10:36:34.115 E/mono-rt (31518):   at (wrapper native-to-managed) System.Object:585983a8-79f2-48a3-ac33-5b4c905219f1 (intptr,intptr,intptr,intptr,int,long)
In mgmain JNI_OnLoad

【问题讨论】：

什么是完整的堆栈跟踪？
10-16 17:27:52.792 D/Mono (10277): Assembly Ref addref Xamarin.Forms.Core[0x66958db8] -> System.Diagnostics.Debug[0x66a5e9c0]: 3 Unhandled Exception: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
@Cheesebaron 有什么建议吗？
该堆栈跟踪应该还有很多
> 0x20 in Android.Widget.AdapterView.IOnItemClickListenerInvoker.n_OnItemClick_Landroid_widget_AdapterView_Landroid_view_View_IJ at /Users/builder/data/lanes/3415/7db2aac3/source/monodroid/src/Mono.Android/platforms/android-23/src/generated/Android.Widget.AdapterView.cs:215,5 C# 和 0x1D in MyProject.MainPage.OnItemSelected at C:\Users\myuser\documents\visual studio 2015\Projects\MyProject\MyProject\MyProject\MainPage.xaml.cs:24,17 C# 询问我是否需要其他日志来帮助我

标签： c# android xamarin realm

【解决方案1】：

正如堆栈跟踪所指示的以及您在 cmets 中发布的路径所示。您已将 PCL 版本安装到平台特定项目中。这就是为什么它会抛出你得到的 PlatformNotSupportedException 异常。

尝试在您的平台特定项目中重新安装 NuGet。或者，您可以手动将引用更改为指向：

packages\Realm.0.78.1\lib\MonoAndroid44\Realm.dll

您不应该在您的平台特定项目中引用可移植文件夹。

【讨论】：

我添加的第一个路径是指 PCL 项目目录 csproj 文件，第二个是指 Droid 项目目录 csproj 文件。我尝试在 droid 项目中重新安装 Realm，但仍然无法正常工作。
在 Android csproj 文件中，您应该仅引用 MonoAndroid44 中的内容。

【解决方案2】：

我在使用 Xamarin.Forms 3.4.0.1008975 和 Realm 4.0.1

时遇到了类似的问题

未处理的异常：System.TypeInitializationException：类型 'Realms.SharedRealmHandle' 的初始化程序引发了异常。发生了

解决方案是从解决方案中的所有项目中完全卸载 nuget Realm 包，然后重新重新安装 Realm。还要确保您在所有项目中都有 FodyWeaver.xml 文件。

【讨论】：