Firebase 在FireStore中设置数据时返回空id

错误消息：

createPostInFireStore({String medaiURl, String location, String description}) async{
    await postsRef.doc(widget.currentUser.id).collection("userposts").doc(_postId).set(
             {"postId": _postId,
          "ownerId": widget.currentUser.id,
          "userName": widget.currentUser.username,
          "mediaurl": medaiURl,
          "description": description,
          "location": location,
          "timeStamp": dateTimeStamp,   
        },
        //SetOptions(merge : true),
    );
  
  }

[错误：flatter/lib/ui/ui\u dart\u state.cc（177）]未处理的异常：NoSuchMethodError:对null调用了getter“id”。
E/颤振（23730）：接收器：空
E/颤振（23730）：尝试呼叫：id
E/颤振（23730）：#0 Object.noSuchMethod（省道：核心补片/Object_补片。省道：51:5）
E/flatter（23730）：#1 UploadState.CreatePostInfireRestore（软件包：聊天界面/组件/社交应用程序主页。dart:397:43）
E/flatter（23730）：#2 UploadState.handleSumitPost（软件包：聊天界面/组件/社交应用程序主页。dart:420:3）
E/颤振（23730）：
E/颤振（23730）：#3#U UploadState.BuildingLoadingScreen。（软件包：聊天界面/组件/社交应用程序主页。dart:443:51）
E/颤振（23730）：#4(InkResponse Estate.)(handleTap)(包装：颤振/src/材料/墨水(well.省道：993:19)
E/颤振（23730）：#5#InkResponseEstate.build。（包装：颤振/src/材料/墨水井。省道：1111:38）
E/flatter（23730）：#6手势识别器.invokeCallback（包：flatter/src/signatures/recognizer.dart:183:24）
电子/颤振（23730）：#7 TapGestureRecognitor.HandletUp（软件包：颤振/src/手势/tap.dart:598:11）
电子/颤振（23730）：#8 BaseTapgestureRecognitor.#检查（软件包：颤振/src/signatures/tap.dart:287:5）
E/flatter（23730）：#9 BaseTapgestureRecognitor.handlePrimaryPointer（包：flatter/src/signatures/tap.dart:222:7）
E/颤振（23730）：#10 PrimaryPointerTestureRecognizer.handleEvent（包：颤振/src/手势/识别器。dart:476:9）
电子/颤振（23730）：#11点外部程序。#调度（包：颤振/src/手势/指针路由器。dart:77:12）
E/颤振（23730）：#12点外部。#调度事件路线。（包装：颤振/src/signatures/pointer_router.省道：122:9）
E/flatter（23730）：#13#LinkedHashMapMixin.forEach（dart:collection patch/compact#u hash.dart:377:8）
E/flatter（23730）：#14点路由器。#调度事件路由（包：flatter/src/signatures/pointer#路由器。dart:120:18）
E/flatter（23730）：#15 PointerRouter.route（包：flatter/src/signatures/pointer_router.dart:106:7）
E/flatter（23730）：#16 GestureBinding.handleEvent（包：flatter/src/signatures/binding.dart:358:19）
E/flatter（23730）：#17 GestureBinding.dispatchEvent（包：flatter/src/signatures/binding.dart:338:22）
E/flatter（23730）：#18 renderbinding.dispatchEvent（包：flatter/src/rendering/binding.dart:267:11）
电子/颤振（23730）：#19手势绑定。#手持点事件（包装：颤振/src/手势/绑定。省道：295:7）
电子/颤振（23730）：#20个手势绑定。(U-flushPointerEventQueue（包装：颤振/src/手势/绑定。省道：240:7）
电子/颤振（23730）：#21手势绑定。"手持指针数据包（包：颤振/src/手势/binding.dart:213:7）
E/颤振（23730）：#22(dart:async/zone.dart:1206:13）
E/flatter（23730）：#23 _CustomZone.runUnary（dart:async/zone.dart:1100:19）
E/颤振（23730）：#24 _CustomZone.runUnaryGuarded（dart:async/zone.dart:1005:7）
E/颤振（23730）：#25 _调用1（省道：ui/挂钩。省道：265:10）
E/颤振（23730）：#26"调度指针数据包（dart:ui/hooks.dart:174:5）
E/颤振（23730）：

在调用

createPostInFireStore

方法之前，确保

小部件.currentUser

具有值

[ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: NoSuchMethodError: The getter 'id' was called on null.
E/flutter (23730): Receiver: null
E/flutter (23730): Tried calling: id
E/flutter (23730): #0      Object.noSuchMethod (dart:core-patch/object_patch.dart:51:5)
E/flutter (23730): #1      _UploadState.createPostInFireStore (package:chat_ui/Components/social_app_homepage.dart:397:43)
E/flutter (23730): #2      _UploadState.handleSumitPost (package:chat_ui/Components/social_app_homepage.dart:420:3)
E/flutter (23730): <asynchronous suspension>
E/flutter (23730): #3      _UploadState.buildLoadingScreen.<anonymous closure> (package:chat_ui/Components/social_app_homepage.dart:443:51)
E/flutter (23730): #4      _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:993:19)
E/flutter (23730): #5      _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:1111:38)
E/flutter (23730): #6      GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:183:24)
E/flutter (23730): #7      TapGestureRecognizer.handleTapUp (package:flutter/src/gestures/tap.dart:598:11)
E/flutter (23730): #8      BaseTapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:287:5)
E/flutter (23730): #9      BaseTapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:222:7)
E/flutter (23730): #10     PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:476:9)
E/flutter (23730): #11     PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:77:12)
E/flutter (23730): #12     PointerRouter._dispatchEventToRoutes.<anonymous closure> (package:flutter/src/gestures/pointer_router.dart:122:9)
E/flutter (23730): #13     _LinkedHashMapMixin.forEach (dart:collection-patch/compact_hash.dart:377:8)
E/flutter (23730): #14     PointerRouter._dispatchEventToRoutes (package:flutter/src/gestures/pointer_router.dart:120:18)
E/flutter (23730): #15     PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:106:7)
E/flutter (23730): #16     GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:358:19)
E/flutter (23730): #17     GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:338:22)
E/flutter (23730): #18     RendererBinding.dispatchEvent (package:flutter/src/rendering/binding.dart:267:11)
E/flutter (23730): #19     GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:295:7)
E/flutter (23730): #20     GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:240:7)
E/flutter (23730): #21     GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:213:7)
E/flutter (23730): #22     _rootRunUnary (dart:async/zone.dart:1206:13)
E/flutter (23730): #23     _CustomZone.runUnary (dart:async/zone.dart:1100:19)
E/flutter (23730): #24     _CustomZone.runUnaryGuarded (dart:async/zone.dart:1005:7)
E/flutter (23730): #25     _invoke1 (dart:ui/hooks.dart:265:10)
E/flutter (23730): #26     _dispatchPointerDataPacket (dart:ui/hooks.dart:174:5)
E/flutter (23730):