Windows Phone 8.1 暂停
Windows Phone 8.1 Suspend
我有一个 windows phone 8.1 应用程序 - 我对 Win Phone 开发完全陌生！
它包含各种页面和自定义用户控件。
我正在尝试暂停应用程序以访问 filesystem/camera。
最初我遇到了一个错误，因为我在 Frame.Navigate 中传递了复杂对象，但我通过将复杂对象添加到 SuspensionManager.SessionState["..."] 并在 OnNavigatedTo 函数中检索它来解决这个问题。
现在，我在应用程序暂停时遇到的错误是：
Type 'Windows.UI.Xaml.UIElement' cannot be serialized. Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute. Alternatively, you can ensure that the type is public and has a parameterless constructor - all public members of the type will then be serialized, and no attributes will be required.
我尝试按照它的建议进行 - 将 [DataContract] 属性添加到 class 并将 [DataMember] 属性添加到所有属性和字段。
我仍然遇到同样的错误。 Google 除了尝试上面的方法之外没有提供很多帮助，所以我浏览了每个自定义 UserControl 并向它们添加了属性 - 仍然没有用，所以我也向每个页面添加了属性 - 主要是出于绝望。
所以现在一切都应该是可序列化的，但我仍然得到同样的错误！我怀疑它是否有用，但这是堆栈跟踪：
at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.ThrowInvalidDataContractException(String message, Type type)
at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.CreateDataContract(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.GetDataContract(RuntimeTypeHandle typeHandle, Type type, SerializationMode mode)
at System.Runtime.Serialization.ClassDataContract.ClassDataContractCriticalHelper..ctor(Type type)
at System.Runtime.Serialization.ClassDataContract..ctor(Type type)
at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.CreateDataContract(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.GetDataContract(RuntimeTypeHandle typeHandle, Type type, SerializationMode mode)
at System.Runtime.Serialization.ClassDataContract.ClassDataContractCriticalHelper..ctor(Type type)
at System.Runtime.Serialization.ClassDataContract..ctor(Type type)
at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.CreateDataContract(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.GetDataContract(RuntimeTypeHandle typeHandle, Type type, SerializationMode mode)
at System.Runtime.Serialization.ClassDataContract.ClassDataContractCriticalHelper..ctor(Type type)
at System.Runtime.Serialization.ClassDataContract..ctor(Type type)
at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.CreateDataContract(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.GetDataContract(RuntimeTypeHandle typeHandle, Type type, SerializationMode mode)
at System.Runtime.Serialization.ClassDataContract.ClassDataContractCriticalHelper..ctor(Type type)
at System.Runtime.Serialization.ClassDataContract..ctor(Type type)
at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.CreateDataContract(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type)
at System.Runtime.Serialization.DataContract.GetDataContract(RuntimeTypeHandle typeHandle, Type type, SerializationMode mode)
at System.Runtime.Serialization.DataContract.CheckAndAdd(Type type, Dictionary2 typesChecked, Dictionary2& nameToDataContractTable)
at System.Runtime.Serialization.XmlObjectSerializerContext.GetDataContractsForKnownTypes(IList`1 knownTypeList)
at System.Runtime.Serialization.DataContractSerializer.get_KnownDataContracts()
at System.Runtime.Serialization.XmlObjectSerializerContext.get_SerializerKnownDataContracts()
at System.Runtime.Serialization.XmlObjectSerializerContext.GetDataContractFromSerializerKnownTypes(XmlQualifiedName qname)
at System.Runtime.Serialization.XmlObjectSerializerContext.ResolveDataContractFromKnownTypes(String typeName, String typeNs, DataContract memberTypeContract)
at System.Runtime.Serialization.XmlObjectSerializerContext.IsKnownType(DataContract dataContract, Type declaredType)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeAndVerifyType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, Boolean verifyKnownType, RuntimeTypeHandle declaredTypeHandle, Type declaredType)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithXsiType(XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle objectTypeHandle, Type objectType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle, Type declaredType)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
at WriteKeyValueOfstringanyTypeToXml(XmlWriterDelegator , Object , XmlObjectSerializerWriteContext , ClassDataContract )
at System.Runtime.Serialization.ClassDataContract.WriteXmlValue(XmlWriterDelegator xmlWriter, Object obj, XmlObjectSerializerWriteContext context)
at WriteArrayOfKeyValueOfstringanyTypeToXml(XmlWriterDelegator , Object , XmlObjectSerializerWriteContext , CollectionDataContract )
at System.Runtime.Serialization.CollectionDataContract.WriteXmlValue(XmlWriterDelegator xmlWriter, Object obj, XmlObjectSerializerWriteContext context)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
at System.Runtime.Serialization.DataContractSerializer.InternalWriteObjectContent(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver)
at System.Runtime.Serialization.DataContractSerializer.InternalWriteObject(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver)
at System.Runtime.Serialization.XmlObjectSerializer.WriteObjectHandleExceptions(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver)
at System.Runtime.Serialization.XmlObjectSerializer.WriteObject(XmlDictionaryWriter writer, Object graph)
at System.Runtime.Serialization.XmlObjectSerializer.WriteObject(Stream stream, Object graph)
at eAuditWindowsPhone.Common.SuspensionManager.d__0.MoveNext()
我真的不确定接下来要尝试什么？我欢迎提出一些建议。
您正在尝试从您的 UI 中序列化一些元素。这几乎不可能，你只是不应该那样做。您需要使 UserControl 中出现的所有内容，每个 属性 及其类型都可序列化。
您只能将属性（DataContract 或 DataMember）添加到您自己创建的 类，并且您将无法使 UI 元素可序列化。
可能是，您的 UserControl 是一个 DataContract，但它仍然具有一些 UIElement 类型的属性，这些属性将不可序列化。
答案：
您应该只存储您感兴趣的 Values（例如 TextBox.Text 或 ToggleButton.IsActive，...）。
我有一个 windows phone 8.1 应用程序 - 我对 Win Phone 开发完全陌生！
它包含各种页面和自定义用户控件。
我正在尝试暂停应用程序以访问 filesystem/camera。
最初我遇到了一个错误，因为我在 Frame.Navigate 中传递了复杂对象，但我通过将复杂对象添加到 SuspensionManager.SessionState["..."] 并在 OnNavigatedTo 函数中检索它来解决这个问题。
现在，我在应用程序暂停时遇到的错误是：
Type 'Windows.UI.Xaml.UIElement' cannot be serialized. Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute. Alternatively, you can ensure that the type is public and has a parameterless constructor - all public members of the type will then be serialized, and no attributes will be required.
我尝试按照它的建议进行 - 将 [DataContract] 属性添加到 class 并将 [DataMember] 属性添加到所有属性和字段。
我仍然遇到同样的错误。 Google 除了尝试上面的方法之外没有提供很多帮助，所以我浏览了每个自定义 UserControl 并向它们添加了属性 - 仍然没有用，所以我也向每个页面添加了属性 - 主要是出于绝望。
所以现在一切都应该是可序列化的，但我仍然得到同样的错误！我怀疑它是否有用，但这是堆栈跟踪：
at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.ThrowInvalidDataContractException(String message, Type type) at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.CreateDataContract(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.GetDataContract(RuntimeTypeHandle typeHandle, Type type, SerializationMode mode) at System.Runtime.Serialization.ClassDataContract.ClassDataContractCriticalHelper..ctor(Type type) at System.Runtime.Serialization.ClassDataContract..ctor(Type type) at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.CreateDataContract(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.GetDataContract(RuntimeTypeHandle typeHandle, Type type, SerializationMode mode) at System.Runtime.Serialization.ClassDataContract.ClassDataContractCriticalHelper..ctor(Type type) at System.Runtime.Serialization.ClassDataContract..ctor(Type type) at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.CreateDataContract(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.GetDataContract(RuntimeTypeHandle typeHandle, Type type, SerializationMode mode) at System.Runtime.Serialization.ClassDataContract.ClassDataContractCriticalHelper..ctor(Type type) at System.Runtime.Serialization.ClassDataContract..ctor(Type type) at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.CreateDataContract(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.GetDataContract(RuntimeTypeHandle typeHandle, Type type, SerializationMode mode) at System.Runtime.Serialization.ClassDataContract.ClassDataContractCriticalHelper..ctor(Type type) at System.Runtime.Serialization.ClassDataContract..ctor(Type type) at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.CreateDataContract(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type) at System.Runtime.Serialization.DataContract.GetDataContract(RuntimeTypeHandle typeHandle, Type type, SerializationMode mode) at System.Runtime.Serialization.DataContract.CheckAndAdd(Type type, Dictionary
2 typesChecked, Dictionary2& nameToDataContractTable) at System.Runtime.Serialization.XmlObjectSerializerContext.GetDataContractsForKnownTypes(IList`1 knownTypeList) at System.Runtime.Serialization.DataContractSerializer.get_KnownDataContracts() at System.Runtime.Serialization.XmlObjectSerializerContext.get_SerializerKnownDataContracts() at System.Runtime.Serialization.XmlObjectSerializerContext.GetDataContractFromSerializerKnownTypes(XmlQualifiedName qname) at System.Runtime.Serialization.XmlObjectSerializerContext.ResolveDataContractFromKnownTypes(String typeName, String typeNs, DataContract memberTypeContract) at System.Runtime.Serialization.XmlObjectSerializerContext.IsKnownType(DataContract dataContract, Type declaredType) at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeAndVerifyType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, Boolean verifyKnownType, RuntimeTypeHandle declaredTypeHandle, Type declaredType) at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithXsiType(XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle objectTypeHandle, Type objectType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle, Type declaredType) at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle) at WriteKeyValueOfstringanyTypeToXml(XmlWriterDelegator , Object , XmlObjectSerializerWriteContext , ClassDataContract ) at System.Runtime.Serialization.ClassDataContract.WriteXmlValue(XmlWriterDelegator xmlWriter, Object obj, XmlObjectSerializerWriteContext context) at WriteArrayOfKeyValueOfstringanyTypeToXml(XmlWriterDelegator , Object , XmlObjectSerializerWriteContext , CollectionDataContract ) at System.Runtime.Serialization.CollectionDataContract.WriteXmlValue(XmlWriterDelegator xmlWriter, Object obj, XmlObjectSerializerWriteContext context) at System.Runtime.Serialization.XmlObjectSerializerWriteContext.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle) at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle) at System.Runtime.Serialization.DataContractSerializer.InternalWriteObjectContent(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver) at System.Runtime.Serialization.DataContractSerializer.InternalWriteObject(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver) at System.Runtime.Serialization.XmlObjectSerializer.WriteObjectHandleExceptions(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver) at System.Runtime.Serialization.XmlObjectSerializer.WriteObject(XmlDictionaryWriter writer, Object graph) at System.Runtime.Serialization.XmlObjectSerializer.WriteObject(Stream stream, Object graph) at eAuditWindowsPhone.Common.SuspensionManager.d__0.MoveNext()
我真的不确定接下来要尝试什么？我欢迎提出一些建议。
您正在尝试从您的 UI 中序列化一些元素。这几乎不可能，你只是不应该那样做。您需要使 UserControl 中出现的所有内容，每个 属性 及其类型都可序列化。
您只能将属性（DataContract 或 DataMember）添加到您自己创建的 类，并且您将无法使 UI 元素可序列化。 可能是，您的 UserControl 是一个 DataContract，但它仍然具有一些 UIElement 类型的属性，这些属性将不可序列化。
答案： 您应该只存储您感兴趣的 Values（例如 TextBox.Text 或 ToggleButton.IsActive，...）。