您在json2csharp中忘记了父对象.

You forgot your parent object in json2csharp.

.NETFiddle上的演示

using System;
using System.Collections.Generic;
using Newtonsoft.Json;

public class ActiveDirectorySchemaExtension // You can switch from the original class name to yours
{
    public string Type { get; set; }        // You should switch to PascalCase to respect C# notation
    public string ObjectType { get; set; }
    public string ObjectId { get; set; }
    public object DeletionTimestamp { get; set; }
    public string AppDisplayName { get; set; }
    public string Name { get; set; }
    public string DataType { get; set; }
    public bool IsSyncedFromOnPremises { get; set; }
    public List<string> TargetObjects { get; set; }
}

public class RootObject
{
    public string Metadata { get; set; }
    public List<ActiveDirectorySchemaExtension> Value { get; set; }
}

public void Main()
{
    var json = "{'odata.metadata':'https://graph.windows.net/mysaasapp.onmicrosoft.com/$metadata#directoryObjects/Microsoft.DirectoryServices.ExtensionProperty','value':[{'odata.type':'Microsoft.DirectoryServices.ExtensionProperty','objectType':'ExtensionProperty','objectId':'f751a646-2cc1-4e30-bfc6-a8217c0ce0a3','deletionTimestamp':null,'appDisplayName':'','name':'extension_33e037a7b1aa42ab96936c22d01ca338_Modulos','dataType':'String','isSyncedFromOnPremises':false,'targetObjects':['User']},{'odata.type':'Microsoft.DirectoryServices.ExtensionProperty','objectType':'ExtensionProperty','objectId':'80aabe1b-b020-41d1-bd2d-cc04af264fe5','deletionTimestamp':null,'appDisplayName':'','name':'extension_33e037a7b1aa42ab96936c22d01ca338_ModulesPerUser','dataType':'String','isSyncedFromOnPremises':false,'targetObjects':['User']},{'odata.type':'Microsoft.DirectoryServices.ExtensionProperty','objectType':'ExtensionProperty','objectId':'6e3d7592-7a66-4792-b408-891251197868','deletionTimestamp':null,'appDisplayName':'','name':'extension_33e037a7b1aa42ab96936c22d01ca338_Comasdasa3dsdaspInfo','dataType':'String','isSyncedFromOnPremises':false,'targetObjects':['User']},{'odata.type':'Microsoft.DirectoryServices.ExtensionProperty','objectType':'ExtensionProperty','objectId':'93a26374-4135-4f29-9f24-4154522449ec','deletionTimestamp':null,'appDisplayName':'','name':'extension_33e037a7b1aa42ab96936c22d01ca338_CompInfo','dataType':'String','isSyncedFromOnPremises':false,'targetObjects':['User']},{'odata.type':'Microsoft.DirectoryServices.ExtensionProperty','objectType':'ExtensionProperty','objectId':'21a8a3d4-f4b4-45b4-8d07-55d450db35f2','deletionTimestamp':null,'appDisplayName':'','name':'extension_33e037a7b1aa42ab96936c22d01ca338_CompanyNameForSaasApp','dataType':'String','isSyncedFromOnPremises':false,'targetObjects':['User']},{'odata.type':'Microsoft.DirectoryServices.ExtensionProperty','objectType':'ExtensionProperty','objectId':'7b3109e0-8710-4d1a-81c3-2b6a83fb62ee','deletionTimestamp':null,'appDisplayName':'','name':'extension_33e037a7b1aa42ab96936c22d01ca338_Compania','dataType':'String','isSyncedFromOnPremises':false,'targetObjects':['User']}]}";
    var o = JsonConvert.DeserializeObject<RootObject>(json);
    Console.WriteLine(o.Value[0].Name);
}

输出:

extension_33e037a7b1aa42ab96936c22d01ca338_Modulos