"Object reference not set to an instance of an object" 持久实体错误

Question

我想在我的 Azure Durable Function 中实现一个实体 class。这应该存储一个代码列表。不幸的是，在执行 Set 方法时出现以下错误：

System.NullReferenceException: 'Object reference not set to an instance of an object.'.

代码如下：

[JsonObject(MemberSerialization = MemberSerialization.OptIn)]
public class OrchestrationStatus
{
    [JsonProperty("orchestrationStatus")]
    public List<string> orchestrationStatus { get; set; } = new List<string>();

    public Task Set(string code) 
    {
        this.orchestrationStatus.Add(code);

        return Task.CompletedTask;
    }

    public Task<List<string>> Get() 
    {
        return Task.FromResult(this.orchestrationStatus);
    }

    [FunctionName(nameof(OrchestrationStatus))]
    public static Task Run([EntityTrigger] IDurableEntityContext ctx)
        => ctx.DispatchAsync<OrchestrationStatus>();
}

Answer 1

如果您尝试使用空引用访问 class 实例的成员，那么您将得到 System.NullReferenceException : 未设置对象引用对象的一个实例.

请查看以下链接以获取更多信息：

.Object reference not set to an instance of an object | SO THREAD

.What does “Object reference not set to an instance of an object” mean| SO THREAD.

.Durable Entities in .NET .& To create Durable function |MS DOC.

Answer 2

我能够通过从实体 class 中删除断点来解决问题。显然，调试器存在错误！

"Object reference not set to an instance of an object" 持久实体错误

"Object reference not set to an instance of an object" error with Durable Entity

c#

azure

azure-durable-functions