应用程序。

Question

当我在与Visual Studio 2019同步的Mac上在iPhone上启动我的应用程序时，出现错误：

error: * Assertion at ../../../../../mono/metadata/class-init.c:4109, condition `klass' not met

我认为它与我的页面有关，因为它在App.cs中的MainPage = new myPage();崩溃。

如果需要，我可以添加整个错误打印。

有帮助吗？

编辑：有关代码的更多信息：

页面的构造函数执行以下操作：

InitializeComponent();
使用WebRequest，StreamWriter，WebResponse
使用JObject来解析anwser并更新一些Label
将Grid添加到我的Layout中：Grid正在使用： AbsoluteLayout，StackLayout，Frame，TapGestureRecognizer，Image，Button，Label

xaml：

 <ContentPage.Content>   
        <StackLayout x:Name="stackMainWrapper"
                     BackgroundColor="White">
            <StackLayout x:Name="stackPageHeader"
                         Padding="20,10,20,0" >
                <StackLayout x:Name="stackHeaderNavigation"
                             Orientation="Horizontal">
                    <myApp:SvgIcon x:Name="svgBtnUser" 
                                         ResourceId="myApp.assets.icons.svg.menu.svg" 
                                         WidthRequest="25"
                                         Margin="0,0,10,0"
                                         VerticalOptions="Center">
                        <myApp:SvgIcon.GestureRecognizers>
                            <TapGestureRecognizer Tapped="GoToMenu" />
                        </myApp:SvgIcon.GestureRecognizers>
                    </myApp:SvgIcon>
                    <Label x:Name="labelPageName" 
                               Text=""
                               Style="{StaticResource TitleLabelStyle}"
                               VerticalOptions="Center" />
                    <Button x:Name="btncreate"
                            Text=""
                            Style="{StaticResource ButtonRegularBlue}"
                            Margin="0,10"
                            Clicked=""
                            HorizontalOptions="EndAndExpand"/>
                    <myApp:SvgIcon x:Name="svgBtnFilterResults" 
                                         ResourceId="myApp.assets.icons.svg.search.svg" 
                                         WidthRequest="25"
                                         Margin="10,0,0,0"
                                         CornerRadius="50"
                                         Padding="10,0"
                                         IsVisible="False"
                                         BackgroundColor="{StaticResource LightGreyStyled}"
                                         HorizontalOptions="End"
                                         VerticalOptions="Center">
                        <myApp:SvgIcon.GestureRecognizers>
                            <TapGestureRecognizer
Tapped="BtnFilterResults_Clicked" />
                        </myApp:SvgIcon.GestureRecognizers>
                    </myApp:SvgIcon>
                </StackLayout>

            </StackLayout>
            <controls:ShadowLine />

            <ScrollView x:Name="scrollPageBody"
                        Margin="0">
                <StackLayout x:Name="PageBody"
                         Padding="20" >
                    <Label x:Name="" 
                       Text=""
                       Style="{StaticResource RegularLabelStyle}"
                       HorizontalTextAlignment="Center"
                       Margin="0,0,0,20"/>
                </StackLayout>
            </ScrollView>
        </StackLayout>
    </ContentPage.Content>
</ContentPage>

编辑：添加异常跟踪：

2019-06-13 11：25：52.743 myapp.iOS [682：181626]错误：*断言为   ../../../../../mono/metadata/class-init.c:4109，条件不是“ klass”   遇见

================================================ ==================本机崩溃报告   ================================================ ===============执行本机代码时获得了SIGABRT。这通常表示致命   Mono运行时或您的
使用的本机库之一错误
应用程序。

================================================ =================基本故障地址报告   ================================================== ===============本地指令指针（0x1d3bb20dc）：0x1d3bb20cc fd周围的内存   7b c1 a8 c0 03 5f d6 10 29 80 d2 01 10 00 d4。{...._ ..）......

0x1d3bb20dc c3 00 00 54 fd 7b bf a9 fd 03 00 91 55 d6 ff 97   ... T。{...... U ...

0x1d3bb20ec bf 03 00 91 fd 7b c1 a8 c0 03 5f d6 90 29 80 d2   ..... {.. .._ ..）.. 0x1d3bb20fc 01 10 00 d4 c3 00 00 54 fd 7b bf a9 fd   03 00 91 ....... T。{.... ..

================================================ ==================本机堆栈跟踪：   ================================================== ============== 0x1005752fc-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：（空）0x10056bc1c-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：（空）0x1d3c259ec-/usr/lib/system/libsystem_platform.dylib：       0x1d3c2b094-/usr/lib/system/libsystem_pthread.dylib：       0x1d3b0bea8-/usr/lib/system/libsystem_c.dylib：中止     0x1006f1c7c-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_find_protocol_wrapper_type 0x1006d2018-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：mono_pmip 0x1006d20a4-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：mono_pmip 0x1005adc78-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：mono_pmip 0x100713638-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_应用程序的总执行期限。   localized_string_format_9 0x100710edc-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_localized_string_format_9 0x100702b78-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_localized_string_format_9 0x100706ad8-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_localized_string_format_9 0x100706ad8-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_localized_string_format_9 0x100703a80-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_localized_string_format_9 0x100701e50-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_localized_string_format_9 0x10057c294-   / var /容器/捆绑/应用   ation / B332FB94-B5DA-4627-8D03-5471B0CE66FC / myapp.iOS.app / myapp.iOS：   mono_pmip 0x10061794c-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：mono_pmip 0x10061af84-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：mono_pmip 0x10047904c-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：（空）0x100479844-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：（空）0x2007d0594-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：    Échecde l'arrêtde l'application：发生错误   客户端IDB1610517，同时执行对主题的答复   xvs / idb / 16.1.0.517 / stop-app 0x2007d5d20-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：       0x2000992dc-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：    实施期限终止。 0x2000a1874-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：       0x200098f60-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：       0x200099850-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：       0x200097b9c-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：       0x200097864-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：       0x20009c3a4-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：       0x20009d188-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：   _performActionsWithDelayForTransitionContext 0x20009c25c-/System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：       0x2007cee30-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：       0x2000a0f5c-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：       0x2007d4328-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：       0x2003d0ba8-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：       0x1d69909fc-   /System/Library/PrivateFrameworks/FrontBoardServices.framework/FrontBoardServices   ：0x1d699a40c-   /System/Library/PrivateFrameworks/FrontBoardServices.framework/FrontBoardServices   ：0x1d6999c14-   /System/Library/PrivateFrameworks/FrontBoardServices.framework/FrontBoardServices   ：0x1d3a557d4-/usr/lib/system/libdispatch.dylib：       0x1d39fa5d8-/usr/lib/system/libdispatch.dylib：       0x1d69cb040-   /System/Library/PrivateFrameworks/FrontBoardServices.framework/FrontBoardServices   ：0x1d69cacdc-   /System/Library/PrivateFrameworks/FrontBoardServices.framework/FrontBoardServices   ：0x1d69cb294-   /System/Library/PrivateFrameworks/FrontBoardServices.framework/FrontBoardServices   ：0x1d3fa7018-   /System/Library/Frameworks/CoreFoundation.framework/CoreFoundation：       0x1d3fa6f98-   /System/Library/Frameworks/CoreFoundation.framework/CoreFoundation：       0x1d3fa6880-   /System/Library/Frameworks/CoreFoundation.framework/CoreFoundation：       0x1d3fa17bc-   /System/Library/Frameworks/CoreFoundation.framework/CoreFoundation：       0x1d3fa10b0-   /System/Library/Frameworks/CoreFoundation.framework/CoreFoundation：   CFRunLoopRunSpecific 0x1d61a179c-   /System/Library/PrivateFrameworks/GraphicsServices.framework/GraphicsServices   ：GSEventRunModal 0x2007d7978-   /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore：   UIApplicationMain 0x10071128c-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_localized_string_format_9 0x10070343c-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_localized_string_format_9 0x100703a80-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_localized_string_format_9 0x100703a80-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_localized_string_format_9 0x100703a80-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_localized_string_format_9 0x100703a80-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_localized_string_format_9 0x100701e50-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_localized_string_format_9 0x10057c294-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：mono_pmip 0x10061794c-   / var /容器/捆绑/应用程序/ B332FB94-B5DA-4627-8D03-5471B0CE66FC / enVisit   4>在<0xffffffff>在   UIKit.UIApplication：UIApplicationMain <0x000bc>在   UIKit.UIApplication：Main上的UIKit.UIApplication：Main <0x0002a>   myapp.iOS上的<0x0006a>应用程序：主机上的<0x00016>   ：runtime_invoke_direct_void_string [] <0x00082>   =============================================== ============== e360.iOS.app/myapp.iOS：mono_pmip 0x10061cf68-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：mono_pmip 0x100560c64-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：（空）0x100700be0-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：xamarin_localized_string_format_9 0x10052adfc-   /var/containers/Bundle/Application/B332FB94-B5DA-4627-8D03-5471B0CE66FC/myapp.iOS.app/myapp.iOS   ：（空）0x1d3a668e0-/usr/lib/system/libdyld.dylib：

================================================ ==================托管堆栈跟踪：   ================================================== ===============在myapp的<0xffffffff>上App：.ctor在<0x0002c>   myapp.iOS.AppDelegate：FinishedLaunching <0x0006e>位于   ：runtime_invoke_direct_bool__this ___ UIApplication_NSDictionary   <0x000b

Answer 1

您必须先初始化页面，然后才能分配给mainPage。

MainPage = new myPage();

Answer 2

我设法分解了崩溃的代码，并逐行取消注释以查看崩溃的原因，显然，在Xamarin iOS上使用dynamic使应用程序崩溃了。

很好..我想避免使用dynamic

加载我的页面时不符合条件“ klass”

应用程序。

2 个答案: