发生对象引用错误 [英] Object reference error occured

问题描述

我在Windows 8服务器上通过文件托管到IIS。那个时候发生了错误。我无法确定问题所在。



对象参考未设置为对象实例



异常详细信息：System.NullReferenceException。

Hi,

I am hosted by file to IIS on Windows 8 server. That time the error occured. I can't identify what is the problem.

Object Reference not set to an instance of an object

Exception Details:System.NullReferenceException.

Stack trace:

[Null Referrence Exception:Object reference not set to an instance of an object]
System.Collects.ObjectModel.Collection.1.Clear()+46
Inttelix.dataCollection.DALCollectionbase'2.BeginLoadData()+353
Inttelix.dataCollection.DALCollectionbase'2.LoadFromDBInternal(IDbTransaction Trnasaction,String Wherecondition,String OrderBy,Object[] parameters)+205

此错误仅在特定服务器上出现。在其他系统中它正在工作。任何人都可以猜出是什么问题？

This error will come only on particular server only. In other systems it is working. Anybody can guess what is the problem?

推荐答案

使用下面的代码



string sourceFile = UploadIpFile。 PostedFile.FileName.ToString（）;



这不会返回Null参考

Use the below code

string sourceFile = UploadIpFile.PostedFile.FileName.ToString();

This will not return Null Reference

你好，

Hello,

Quote：

对象引用未设置为对象的实例

Object Reference not set to an instance of an object

当您尝试引用的对象不在堆中时，会发生此错误。



何时分配对象在堆上???



：假设我说：



Class1 c = new Class1（）;

///请注意new关键字在堆上分配对象。



- 如果我不说new那么Class1是只是一个蓝色的印刷品，直到我说新才会实现。



- 如果你只是说：



Class1 c;



及以后代码中你说：



c。 some_method（）; ///这不会工作，并且会在此行引发异常。





试用这段代码：

This error occurs when the object you are trying to reference is not present in the heap.

When is an object allocated on the heap???

: Suppose i say:

Class1 c = new Class1();
///Please note that the "new" keyword allocates the object on the heap.

- If i dont say "new" then "Class1" is just a blue print it does not come into realization until i say "new".

- If you simply say:

Class1 c;

and later in your code you say :

c.some_method();///this wont work and an exception will be thrown at this line.


Try out this code:

class Program
   {
       public void method()
       {
           Console.WriteLine("hello");

       }

       static void Main(string[] args)
       {
           Program p = null;
           p.method(); ////Exception will be thrown at this line. 
           Console.ReadLine();

       }
   }

（）;

Console.ReadLine（）;



}

}





- 在你的情况下情况可能也类似。因此，您获得错误的行设置了一个断点（右键单击该行并设置断点）。



- 现在将鼠标悬停在对象/在该行之前的位置使用的对象（在该行中使用）。您将看到对象/对象为空。



- 现在使用new关键字重新初始化对象。这应该有所帮助。只需要一点调试就可以解决问题了。



谢谢，

-Rahul

();
Console.ReadLine();

}
}


- In your case also the situation may be something similar. So the line where you get an error set a break point(right click that line and set a break point).

- Now hover your the mouse to the object/objects(used in that line) used in places before that line. You will see that the object/objects are null.

- Now reinitialize the objects by using the "new" keyword. This should help. Just a little debugging and the problem should go.

Thanks,
-Rahul

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