object reference not set to an instance of an object error

Question

I have controller to save record. and my code is as follows

[HttpPost]
public ActionResult CreateP3(Process process)
{
var tr = process.StageID + process.PIPENO + process.Status;
var checkme = (from x in db.Processes
where x.StageID + x.PIPENO + x.Status == tr && x.Status == "OK"
select x).ToList();
if (checkme.Count > 0)
{
ModelState.AddModelError("PIPENO", "You are trying Duplicate Pipe Entry");
}
if (ModelState.IsValid)
{
if (process.PipeAl.Order.THK > 1)
{
process.MPP = 20;
}
else
{
process.MPP = 1;
}
process.CuttingSpeed = (process.ActualMeter*1000)/process.CuttingTime;
db.Processes.Add(process);
db.SaveChanges();
return RedirectToAction("IndexP3");
}

But I get object reference not set on an instance of an object error. Pls help

Raju Fodse · Answer

How can access data from third level relation table in controller.

Suraj Kumar · Answer

Hello Raju, First check process is null or not then check process.PipeAl After that check process.PipeAl.Order if the process.PipeAl and process.PipeAl.Order will not be null then you can access the value of process.PipeAl.Order.THK. You can check it's value whether it is null or not using breakpoint and quickwath. For example if you want to check rocess.PipeAl is null or not then create a breakpoint and select that text and click on Shift+F9. It will give you quick watch. Alternatively you can check in view and browser console. Regard Suraj

Raju Fodse · Answer

In my Order Table THK filed don't have any null value I got error at line 14 ( if (process.PipeAl.Order.THK > 1) )

Suraj Kumar · Answer

Hello Raju, You need to check process value in model is coming or not. I think it is not coming and it will be null so accessing anything or column with .(dot) will give that error. You can write the code to avoid and handle null reference error as below. if(check!=null) { //Your code here. } Regard Suraj

Ajay Gupta · Answer

at which line ?