Unhandle Reference Exception

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1.00/5 (1 vote)

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C#

private void validateName_Click(object sender, EventArgs e)
        {
            if (nameObj.InitializeDataFiles() == mdNAMEOBJECTLib.ProgramStatus.NoError)
            {               
                try
                {
                    File = new StreamReader("../../mdName.sdf");
                }
                catch (Exception)
                {
                    resultString.Text = "Can't open sample file";
                }               
                
                while ((FullName = File.ReadLine()) != null)
                {
                    nameObj.ClearProperties();
                    nameObj.FullName = FullName;
                    nameObj.Parse();
                    fullName.Text = FullName;
                    Records++;
                }
            }
        }

I got error message:Unhandle exception of type 'System.NullReferenceExceiption' occured in mdNameObj.exe.
Additional Information: Object reference not set an instance of an object.

How to fix this error. Thanks,

Posted 12-Dec-11 9:36am

chaupha

Updated 12-Dec-11 9:41am

#realJSOP

v3

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Comments

Monjurul Habib 12-Dec-11 15:41pm

provide more detail info.

Sergey Alexandrovich Kryukov 12-Jan-12 17:31pm

"Unhandle Reference Exception" is gibberish. Exception handling sucks. Why assigning this resultString -- no file name, nothing, wrong place to handle. You need to let exception to propagate. Non-local name FullName in loop suck -- it should be local. Use the debugger.
--SA

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#realJSOP · Answer 1 · 2011-12-12T09:41:00

Solution 1

Use the debugger to find out which object is null, and fix your mistake (you didn't indcate what line of code was throwing the excveption, so I assume you haven't used the debugger yet). The most likely culprits are nameObj and File (which sucks as a variable name since it's also the name of a .Net nameSpace).

Posted 12-Dec-11 9:41am

#realJSOP

Updated 12-Dec-11 9:43am

v2

Comments

chaupha 12-Dec-11 16:25pm

while ((FullName = File.ReadLine()) != null)

The debugger pointed out the error in this line. Sorry, I didn't post.

#realJSOP 12-Dec-11 17:18pm

so, which variable is null? FullName or File?

chaupha 12-Dec-11 17:51pm

The FullName is null.

[no name] 12-Dec-11 20:18pm

5!