powershell - 为什么在Sharepoint上可见90+时List.ItemCount报告零项？

Question

我正在编写一个脚本，以清除列表中的所有现有项目，然后再向其添加新项目。不幸的是，当我可以通过Sharepoint查看全部90多个项目时，我不知道为什么我的列表报告其中有零个项目。这是我正在运行的代码:

function uploadDataFromCSV($_ctx, $_listName)
{
    Write-Host "[$_listName]"

    $list = $_ctx.Web.Lists.GetByTitle($_listName)
    if($list.Exists){write-host "yes"}
    $list.ItemCount # Always returns 0

    # Clear all the items from the list if the flag has been set
    if($OverwriteItems)
    {
        Write-Host 'Deleting contents of list'
        $list.ItemCount
        $listItems = $list.Items
        # Delete from last to first because %REASONS%
        for($index = $listItems.Count-1; $index -gt -1; $index--)
        {
           $listItems[$index].Delete()
        }
        Write-Host 'List has been reset'
    }

    Write-Host 'Reading CSV file'
    $csv = Import-Csv "$csvDir\$_listName.csv"
    $headers = $csv | Get-Member -MemberType NoteProperty | %{$_.name}

    $itemsAdded = 0
    foreach($line in $csv)
    {
        $itemCreateInfo = New-Object Microsoft.SharePoint.Client.ListItemCreationInformation
        $newItem = $list.AddItem($itemCreateInfo)

        # Map each value in the line to its corresponding header
        $headers | % {
            $statement = [scriptblock]::Create('$newItem["{0}"] = $line.{0}' -f $_)
            $statement.Invoke()
        }
        $newItem.Update()
        $itemsAdded++
    }
    Write-Host' Importing items'
    #Add the items to the list
    #$_ctx.ExecuteQuery()
    Write-Host $itemsAdded 'items imported'
}

#Load .NET CSOM modules
Add-Type -Path "C:\Program Files\Common Files\microsoft shared\Web Server Extensions\15\ISAPI\Microsoft.SharePoint.Client.dll"
Add-Type -Path "C:\Program Files\Common Files\microsoft shared\Web Server Extensions\15\ISAPI\Microsoft.SharePoint.Client.Runtime.dll"

$site_url = "https://url.goes/here"
$username = "user@domain.com"
$password = ConvertTo-SecureString -AsPlainText -Force 'gibberishPassword'

#Set up the context and set its credentials
$ctx = New-Object Microsoft.SharePoint.Client.ClientContext($site_url)
$credentials = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($username, $password)
$ctx.Credentials = $credentials

uploadDataFromCSV $ctx "TableName"

我需要列表中的项目数，以便可以逐个进行遍历和删除(我知道我知道，删除列表并从模板还原不是一种选择)。我知道我获取了正确的列表，因为在脚本的下方添加的项目已正确插入-脚本运行后，我可以刷新Sharepoint并查看除列表中现有项目以外的新添加的项目。

为什么 $list.ItemCount表示列表中没有任何内容？

Answer 1

当使用SharePoint CSOM来检索客户端对象(例如List)或其属性(例如List.ItemCount property)时，必须使用ClientContext.ExecuteQuery method进行请求。

在您的情况下，由于尚未加载List对象，因此未初始化List.ItemCount property，下面的示例演示如何获取List.ItemCount property:

$list = $context.Web.Lists.GetByTitle($listName) #get List object
$context.Load($list) #prepare query to load List object 
$context.ExecuteQuery() #submit query to request List Object
$itemsCount = $list.ItemCount #ItemCount property is loaded now and returns list items count