Object reference not set to an instance of an object.

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When Running Application I got this Exception: Object reference not set to an instance of an object. on Below code.

C#

fromPageRange = Functions.ToInt32(((Label)grdFiles.Rows[i].FindControl("lblFromPageRange")).Text);

Posted 19-Jul-11 23:53pm

rajjosh

Updated 19-Jul-11 23:55pm

walterhevedeich

v2

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walterhevedeich · Answer 1 · 2011-07-19T23:57:00

Solution 1

It could be that grdFiles.Rows[i].FindControl("lblFromPageRange")) does not exist. On Visual Studio, you can set a breakpoint before this line, and then run the app. When it stops on the breakpoint, add grdFiles.Rows[i].FindControl("lblFromPageRange")) to the watch and try to see if its not null.

Posted 19-Jul-11 23:57pm

walterhevedeich

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rajjosh 20-Jul-11 6:07am

it gives null value in watch

walterhevedeich 20-Jul-11 10:22am

You found the problem then. You need to check why its returning null, or probably, you might not want to assign it to fromPageRange if its null.

Herman<T>.Instance · Answer 2 · 2011-07-19T23:57:00

Solution 2

your FindControl does not find the control which result in NULL.

So:

Label aLabel = (Label)grdFiles.Rows[i].FindControl("lblFromPageRange"))
if (null != aLabel && null != aLabel.Text)
{
Int32 value = Convert.ToInt32(aLabel.Text);
}

Posted 19-Jul-11 23:57pm

Herman<T>.Instance

Mohammad A Rahman · Answer 3 · 2011-07-23T13:25:00

It might helps,

C#

public int ParseText(int positionInArray, string whichLabelToFind)
{
    Label aLabel = positionInArray <= grdFiles.Rows.Count ? (Label)grdFiles.Rows[positionInArray].FindControl(whichLabelToFind) : null;
    int result = default(int);
    return aLabel != null ? Int32.TryParse(aLabel.Text, out result) ? result : result : result;
}

:)

Daxa Rughani · Answer 4 · 2011-07-23T09:08:00

Solution 3

You could try the following.

bool isValid = int32.TryParse( (Label)grdFiles.Rows[i].FindControl("lblFromPageRange")), out fromPageRange );

This will not throw but you must handle if isValid = false case.

Posted 23-Jul-11 9:08am

Daxa Rughani

Updated 23-Jul-11 9:22am

v2