使用 Microsoft Graph 为日历创建新事件时出现空异常

Posted 2023-03-28

【中文标题】使用 Microsoft Graph 为日历创建新事件时出现空异常

【英文标题】：Null exception when creating new event for calendar with Microsoft Graph

【发布时间】：2017-09-01 17:42:30

【问题描述】：

我在这里真的很困惑并且在转圈。

我有这个基本代码：

public async Task<bool> CreateEventData(OutlookCalendarData.OutlookCalendarData oData)

    try
    
        await oData.CreateEvent(oData.Weeks[0], _graphClient);
    
    catch (Exception ex)
    
        SimpleLog.Log(ex);
    
    return true;

调用的代码在这里：

public async Task<bool> CreateEvent(Week oWeek, GraphServiceClient graphClient)

    // Event Body
    // TODO: Build proper body text
    ItemBody body = new ItemBody
    
        Content = oWeek.WeeklyBibleReading,
        ContentType = BodyType.Text
    ;

    // Start Time
    string strStartDateTime = oWeek.Date.ToString("yyyy-MM-dd") + "T" + oWeek.StartTime + ":00";
    DateTime dateStartDateTime = DateTime.Parse(strStartDateTime);
    DateTimeTimeZone startTime = new DateTimeTimeZone
    
        DateTime = dateStartDateTime.ToString("o"),
        TimeZone = TimeZoneInfo.Local.Id
    ;

    // End Time
    DateTimeTimeZone endTime = new DateTimeTimeZone
    
        DateTime = dateStartDateTime.AddMinutes(oWeek.EventDuration).ToString("o"),
        TimeZone = TimeZoneInfo.Local.Id
    ;

    // Add the event
    Event createdEvent = await graphClient.Me.Calendars[_CalendarID]
        .Events
        .Request()
        .AddAsync(new Event
        
            Subject = oWeek.Title,
            Body = body,
            Start = startTime,
            End = endTime,
            IsReminderOn = true,
            ReminderMinutesBeforeStart = 1024,
        );

    // Extended Properties
    if (createdEvent != null)
    
        createdEvent.SingleValueExtendedProperties.Add(
            new SingleValueLegacyExtendedProperty
            
                Id = "String " + Guid.NewGuid().ToString() + " Name TruckleSoft1",
                Value = "CLM_MidweekMeeting"
            );

        return true;
    

    return false;

但是我在这个位上遇到了一个异常：

Event createdEvent = await graphClient.Me.Calendars[_CalendarID]
    .Events
    .Request()
    .AddAsync(new Event
    
        Subject = oWeek.Title,
        Body = body,
        Start = startTime,
        End = endTime,
        IsReminderOn = true,
        ReminderMinutesBeforeStart = 1024,
    );

例外：

<LogEntry Date="2017-09-01 18:38:08" Severity="Exception" Source="OutlookCalIFConsole.Outlook+&lt;CreateEventData&gt;d__17.MoveNext" ThreadId="10">
    <Exception Type="System.NullReferenceException" Source="OutlookCalIFConsole.OutlookCalendarData.OutlookCalendarData+&lt;CreateEvent&gt;d__10.MoveNext">
        <Message>Object reference not set to an instance of an object.</Message>
        <StackTrace>   at OutlookCalIFConsole.OutlookCalendarData.OutlookCalendarData.&lt;CreateEvent&gt;d__10.MoveNext() in D:\My Programs\2017\OutlookCalIFConsole\OutlookCalIFConsole\OutlookCalendarData\OutlookCalendarData.cs:line 97
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
       at OutlookCalIFConsole.Outlook.&lt;CreateEventData&gt;d__17.MoveNext() in D:\My Programs\2017\OutlookCalIFConsole\OutlookCalIFConsole\Outlook.cs:line 186</StackTrace>
    </Exception>
</LogEntry>

我很困惑。我已经验证我使用的所有位都不为空。

更新

我稍微移动了我的代码，现在可以确认它确实在日历中创建了事件。扩展属性例外：

// Extended Properties
if (createdEvent != null)

    createdEvent.SingleValueExtendedProperties.Add(
        new SingleValueLegacyExtendedProperty
        
            Id = "String " + Guid.NewGuid().ToString() + " Name TruckleSoft1",
                Value = "CLM_MidweekMeeting"
        );

    return true;

更新

啊，在调试模式下，仔细观察，Event 对象中的SingleValueExtendedProperties 为空。我不知道如何构建一组新的属性。

更新

我试过了，但它不喜欢它：

List<SingleValueLegacyExtendedProperty> extendedProperties =
    new List<SingleValueLegacyExtendedProperty>();

extendedProperties.Add(new SingleValueLegacyExtendedProperty

    Id = "String " + Guid.NewGuid().ToString() + " Name TruckleSoft1",
        Value = "CLM_MidweekMeeting"
);

// Add the event

Event createdEvent = await _graphClient.Me.Calendars[oData.CalendarID]
    .Events
    .Request()
    .AddAsync(new Event
    
        Subject = oWeek.Title,
        Body = body,
        Start = startTime,
        End = endTime,
        IsReminderOn = true,
        ReminderMinutesBeforeStart = 1024,
        SingleValueExtendedProperties = extendedProperties
    );

更新

我已阅读：

https://developer.microsoft.com/en-us/graph/docs/api-reference/v1.0/api/singlevaluelegacyextendedproperty_post_singlevalueextendedproperties

但我不明白为什么我的方法真的失败了。

【参考方案1】：

您在正确的轨道上，您需要初始化extendedProperties 属性。但是，您想要的不是List<T>，而是EventSingleValueExtendedPropertiesCollectionPage。

试试这个：

var extendedProperties = new EventSingleValueExtendedPropertiesCollectionPage();
extendedProperties.Add(new SingleValueLegacyExtendedProperty

    Id = "String " + Guid.NewGuid().ToString() + " Name TruckleSoft1",
    Value = "CLM_MidweekMeeting"
);

【讨论】：

啊，这么简单。谢谢你。我注意到手册中的示例是"id":"String 66f5a359-4659-4830-9070-00040ec6ac6e Name Fun"。 Guid 有花括号。当我查看调试时，它们在我的身上丢失了。所以我现在做：Id = String.Format("String 0 Name 1", Guid.NewGuid().ToString(), "TruckleSoft1")