当我从包含ZXing BarcodeImageView的视图和带有 IsVisible="{Binding BindMe, Converter={converter:BoolConverter}}" 的标签导航回来时，我的应用程序崩溃 System.ObjectDisposedException: Cannot access a disposed object. Object name: 'Android.Widget.ImageView'.
当我从Xamarin.Forms 2.5到3.2.x时，引入了这个问题
包的版本：
Xamarin.Forms - 3.2.0.839982
Prism.Unity.Forms - 7.10.431
ZXing.Net.Mobile.Forms - 2.4.1
Xamarin.Android.Support.Design - 27.0.2.1
Xamarin.Android.Support.v4 -27.0.2.1
Xamarin.Android.Support.v7.AppCompat - 27.0.2.1
Xamarin.Android.Support.v7.CardView - 27.0.2.1
Xamarin.Android.Support.v7.MediaRouter - 27.0.2.1
PrismContentPage（用于导航按钮）
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:prism="clr-namespace:Prism.Mvvm;assembly=Prism.Forms"
prism:ViewModelLocator.AutowireViewModel="True"
x:Class="TestCrash.Views.PrismContentPage1">
<Button Text="Navigate" Command="{Binding Navigate}" />
</ContentPage>
PrismContentPage
using Prism.Commands;
using Prism.Mvvm;
using Prism.Navigation;
using System;
using System.Collections.Generic;
using System.Linq;
namespace TestCrash.ViewModels
{
public class PrismContentPage1ViewModel : BindableBase
{
private readonly INavigationService _navigationService;
public DelegateCommand Navigate { get; set; }
public PrismContentPage1ViewModel(INavigationService navigationService)
{
_navigationService = navigationService;
Navigate = new DelegateCommand(NavigateToMain);
}
private void NavigateToMain()
{
_navigationService.NavigateAsync("MainPage");
}
}
}
MainPage（包含ZXing和标签）
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:zxing="clr-namespace:ZXing.Net.Mobile.Forms;assembly=ZXing.Net.Mobile.Forms"
xmlns:zxcm="clr-namespace:ZXing.Common;assembly=zxing.portable"
xmlns:converter="clr-namespace:TestCrash.ValueConverters;assembly=TestCrash"
x:Class="TestCrash.Views.MainPage"
Title="{Binding Title}">
<StackLayout BackgroundColor="White">
<Label Text="Test" HorizontalTextAlignment="Center" IsVisible="{Binding BindMe, Converter={converter:BoolConverter}}" />
<zxing:ZXingBarcodeImageView
BarcodeValue="12345678"
IsEnabled="True"
HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand"
HeightRequest="200"
WidthRequest="200"
BarcodeFormat ="QR_CODE"
IsVisible="True">
<zxing:ZXingBarcodeImageView.BarcodeOptions>
<zxcm:EncodingOptions Width="180" Height="180" />
</zxing:ZXingBarcodeImageView.BarcodeOptions>
</zxing:ZXingBarcodeImageView>
</StackLayout>
</ContentPage>
MainPageViewModel
using Prism.Commands;
using Prism.Mvvm;
using Prism.Navigation;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace TestCrash.ViewModels
{
public class MainPageViewModel : ViewModelBase
{
private string _bindMe;
public string BindMe
{
get => _bindMe;
set
{
SetProperty(ref _bindMe, value);
}
}
public MainPageViewModel(INavigationService navigationService)
: base(navigationService)
{
Title = "Main Page";
}
}
}
ValueConverter
public class BoolConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
return !string.IsNullOrEmpty((string)value);
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
单声道Stacktrace
10-17 09:29:40.769 D/Mono ( 7417): DllImport searching in: '__Internal' ('(null)').
10-17 09:29:40.769 D/Mono ( 7417): Searching for 'java_interop_jnienv_new_local_ref'.
10-17 09:29:40.769 D/Mono ( 7417): Probing 'java_interop_jnienv_new_local_ref'.
10-17 09:29:40.769 D/Mono ( 7417): Found as 'java_interop_jnienv_new_local_ref'.
10-17 09:29:40.821 D/ ( 7417): HostConnection::get() New Host Connection established 0x9c1a97c0, tid 7443
10-17 09:29:40.822 I/OpenGLRenderer( 7417): Initialized EGL, version 1.4
10-17 09:29:40.822 W/OpenGLRenderer( 7417): Failed to choose config with EGL_SWAP_BEHAVIOR_PRESERVED, retrying without...
10-17 09:29:40.840 D/EGL_emulation( 7417): eglCreateContext: 0x9c31fb20: maj 3 min 0 rcv 3
10-17 09:29:40.850 D/EGL_emulation( 7417): eglMakeCurrent: 0x9c31fb20: ver 3 0 (tinfo 0x9c16f230)
10-17 09:29:40.851 E/eglCodecCommon( 7417): glUtilsParamSize: unknow param 0x00008cdf
10-17 09:29:40.851 E/eglCodecCommon( 7417): glUtilsParamSize: unknow param 0x00008824
10-17 09:29:40.901 D/EGL_emulation( 7417): eglMakeCurrent: 0x9c31fb20: ver 3 0 (tinfo 0x9c16f230)
10-17 09:29:41.025 D/Mono ( 7417): Assembly Ref addref TestCrash.Android[0xab1bdba0] -> ZXing.Net.Mobile.Forms.Android[0xab1bed40]: 2
10-17 09:29:41.025 D/Mono ( 7417): Assembly Ref addref TestCrash.Android[0xab1bdba0] -> ZXingNetMobile[0xab1bf040]: 3
10-17 09:29:41.063 D/Mono ( 7417): DllImport searching in: '__Internal' ('(null)').
10-17 09:29:41.063 D/Mono ( 7417): Searching for 'java_interop_jnienv_call_nonvirtual_float_method_a'.
10-17 09:29:41.063 D/Mono ( 7417): Probing 'java_interop_jnienv_call_nonvirtual_float_method_a'.
10-17 09:29:41.063 D/Mono ( 7417): Found as 'java_interop_jnienv_call_nonvirtual_float_method_a'.
10-17 09:29:41.105 W/art ( 7417): JNI RegisterNativeMethods: attempt to register 0 native methods for md5270abb39e60627f0f200893b490a1ade.ViewRenderer_2
10-17 09:29:48.434 D/Mono ( 7417): Assembly Ref addref TestCrash[0xab1be200] -> zxing.portable[0xab1bef80]: 2
10-17 09:29:48.434 D/Mono ( 7417): Assembly Ref addref TestCrash[0xab1be200] -> ZXing.Net.Mobile.Forms[0xab1beda0]: 3
10-17 09:29:48.435 D/Mono ( 7417): Assembly Ref addref ZXing.Net.Mobile.Forms[0xab1beda0] -> zxing.portable[0xab1bef80]: 3
10-17 09:29:48.439 D/Mono ( 7417): Unloading image System.Collections.dll [0x9c0d3400].
10-17 09:29:48.439 D/Mono ( 7417): Image addref System.Collections[0x9b6d4080] -> System.Collections.dll[0xaa899e00]: 5
10-17 09:29:48.439 D/Mono ( 7417): Config attempting to parse: 'System.Collections.dll.config'.
10-17 09:29:48.439 D/Mono ( 7417): Config attempting to parse: '/usr/local/etc/mono/assemblies/System.Collections/System.Collections.config'.
10-17 09:29:48.439 D/Mono ( 7417): Assembly Ref addref zxing.portable[0xab1bef80] -> System.Collections[0xab1bf160]: 3
Resolved pending breakpoint at 'BoolConverter.cs:11,1' to object TestCrash.ValueConverters.BoolConverter.Convert (object value, System.Type targetType, object parameter, System.Globalization.CultureInfo culture) [0x00001].
Error while resolving expression: One or more errors occurred.
10-17 09:29:56.613 I/Choreographer( 7417): Skipped 493 frames! The application may be doing too much work on its main thread.
10-17 09:29:56.737 D/Mono ( 7417): Assembly Ref addref ZXing.Net.Mobile.Forms.Android[0xab1bed40] -> System[0xad997840]: 5
10-17 09:29:56.743 W/art ( 7417): JNI RegisterNativeMethods: attempt to register 0 native methods for md5ba571508d8a3b4abfeff2ff661a05265.ZXingBarcodeImageViewRenderer
10-17 09:29:56.750 D/Mono ( 7417): Assembly Ref addref ZXingNetMobile[0xab1bf040] -> zxing.portable[0xab1bef80]: 4
10-17 09:29:56.750 D/Mono ( 7417): Assembly Ref addref ZXing.Net.Mobile.Forms.Android[0xab1bed40] -> zxing.portable[0xab1bef80]: 5
10-17 09:29:56.750 D/Mono ( 7417): Assembly Ref addref ZXing.Net.Mobile.Forms.Android[0xab1bed40] -> Xamarin.Forms.Core[0xab1beb60]: 10
10-17 09:29:56.940 D/Mono ( 7417): Unloading image System.Runtime.Extensions.dll [0x9c0d6600].
10-17 09:29:56.940 D/Mono ( 7417): Image addref System.Runtime.Extensions[0x9b6d39c0] -> System.Runtime.Extensions.dll[0xaa89b200]: 5
10-17 09:29:56.940 D/Mono ( 7417): Config attempting to parse: 'System.Runtime.Extensions.dll.config'.
10-17 09:29:56.940 D/Mono ( 7417): Config attempting to parse: '/usr/local/etc/mono/assemblies/System.Runtime.Extensions/System.Runtime.Extensions.config'.
10-17 09:29:56.940 D/Mono ( 7417): Assembly Ref addref zxing.portable[0xab1bef80] -> System.Runtime.Extensions[0xab1bfa60]: 3
Unhandled Exception:
System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'Android.Widget.ImageView'.