无效投射例外 - 投射无效

Question

这是我网站上的错误。在Visual Studio中没有错误，它编译得很好。当我在本地运行网站并点击按钮在Chrome或任何其他浏览器中显示区域时，会发生这种情况。我完全被这个难住了，我正在寻找任何帮助？不胜感激。

System.InvalidCastException: Specified cast is not valid. 
at MySite.Web.Areas.Mpa.Controllers.ZonesController.d__7.MoveNext() in C:\MySite\Development\routing_branch\src\MySite.Web\Areas\Mpa\Controllers\ZonesController.cs:line 125 
--- 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 System.Web.Mvc.Async.TaskAsyncActionDescriptor.EndExecute(IAsyncResult asyncResult) 
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass37.b__36(IAsyncResult asyncResult) 
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) 
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase`1.End() 
at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) 
at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.b__3d() 
at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.b__3f() 

这是我打电话的方法，显示行125：

93 public async Task<PartialViewResult> MapViewModal() 
94 { 
95  int? impersonatorTenantId; 
96  int value; 
97  object obj; 
98  IZoneAppService zoneAppService = this._zoneAppService; 
99  if (this.AbpSession.ImpersonatorTenantId.HasValue) 
100  { 
101   impersonatorTenantId = this.AbpSession.ImpersonatorTenantId; 
102   value = impersonatorTenantId.Value; 
103  } 
104  else 
105  { 
106   impersonatorTenantId = this.AbpSession.TenantId; 
107   value = impersonatorTenantId.Value; 
108  } 
109  List<ZoneListDto> zonesByTenantId = await zoneAppService.GetZonesByTenantId(value, true); 
110  if (zonesByTenantId == null || zonesByTenantId != null && zonesByTenantId.Count == 0) 
111  { 
112   zonesByTenantId = new List<ZoneListDto>(); 
113  } 
114  ITenantSettingsAppService tenantSettingsAppService = this._tenantsettingsAppService; 
115  if (this.AbpSession.ImpersonatorTenantId.HasValue) 
116  { 
117   impersonatorTenantId = this.AbpSession.ImpersonatorTenantId; 
118   obj = impersonatorTenantId.Value; 
119  } 
120  else 
121  { 
122   impersonatorTenantId = this.AbpSession.TenantId; 
123   obj = impersonatorTenantId.Value; 
124  } 
125  string tenantCoordinates = await tenantSettingsAppService.GetTenantCoordinates((long)obj); 
126  ZonesMapView zonesMapView = new ZonesMapView() 
127  { 
128   Zones = zonesByTenantId, 
129   TenantCoordinates = tenantCoordinates 
130  }; 
131  return this.PartialView("_MapViewModal", zonesMapView); 
132 } 

我的表布局是这样的：

dbo.MySiteZones 
Columns: 
Id (PK, bigint, not null) 
TenantId (int, not null) 
Name (nvarchar(255), not null) 
Caption (nvarchar(600), null) 
IsActive (bit, not null) 
IsDeleted (bit, not null) 
DeleterUserId (bigint, null) 
DeletionTime (datetime, null) 
LastModificationTime (datetime, null) 
LastModifierUserId (bigint, null) 
CreationTime (datetime, not null) 
CreatorUserId (bigint, null) 
PolygonCoordinates (nvarchar(max), null) 
HexColor (nvarchar(12), null) 
PolygonCoordinatesReversed (nvarchar(max), null) 

Answer 1

不能直接施放object到long。您应该使用Convert.ToInt64()甚至蒙上对象值：

string tenantCoordinates = await tenantSettingsAppService.GetTenantCoordinates(Convert.ToInt64(obj)); 

PS：你为什么不宣布 'OBJ' 为long（并相应地更改名字:)）：

long obj; 
// ... 
string tenantCoordinates = await tenantSettingsAppService.GetTenantCoordinates(obj); 

编辑更新错误的库调用，如@Jonno所述

Answer 2

只要obj是对int的引用，您可以尝试显式转换为int ri铸造long前GHT：.GetTenantCoordinates((long)(int)obj)

我想，但是你可以声明obj为int或long。