C# 未将对象引用设置为对象的实例 #3
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object reference not set to an instance of an object #3
提问by Prasad
I am getting the object reference error in just start of the method.
我在方法刚开始时就收到了对象引用错误。
For Ex.:
例如：
259: public ActionResult ShowAddress(FormCollection formCollection)
260: {
In the above sample i am getting the error Line number 260.
在上面的示例中，我收到错误行号 260。
采纳答案by JaredPar
Here is the code from the question comments
这是问题评论中的代码
259: public ActionResult ShowAddress(FormCollection formCollection) {
260: long _userId= long.Parse(formCollection["UserId"].ToString());
261: UserDetails _userDetails = _userDAL.GetUserDetails(_userId);
262: if(!string.IsNullOrEmpty(_userDetails.Address1)) return RedirectToAction("GetAddress", "User"); else return View(); }
If you're seeing a NullReferenceException at line 260, either formCollection or the result of formCollection["UserId"] is null. You need to account for this in your code. For instance you could do the following.
如果您在第 260 行看到 NullReferenceException，则 formCollection 或 formCollection["UserId"] 的结果为 null。您需要在代码中考虑到这一点。例如，您可以执行以下操作。
public ActionResult ShowAddress(FormCollection formCollection) {
if ( null == formCollection ) {
return View();
}
object obj = formCollection["UserId"];
if ( null == obj ) {
return View();
}
long _userId = long.Parse(obj.ToString());
...
}
回答by corlettk
Finally, Enough information to attempt to post an answer...
最后，有足够的信息尝试发布答案......
I suppose formCollection must be null.
我想 formCollection 必须为空。
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