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Obtained error: Object reference not set to an instance of an object.

Server Error in '/' Application.
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drpRegions is set correctly but the 'Object reference not set to an instance of an object.' error is obtained

Object reference not set to an instance of an object.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:


Line 550:        Dim plantRowItem As dsPlants.tblPlantsRow
Line 551:        For Each plantRowItem In dsPlants.tblPlants
Line 552:            If ((plantRowItem.RegionCode.ToString() = drpRegions.SelectedItem.Value.ToString()) _
Line 553:            And (plantRowItem.CellCode.ToString() = drpCells.SelectedItem.Value.ToString()) _
Line 554:            And ((drpPlants.SelectedIndex <> -1) And (plantRowItem.PlantName.ToString() = drpPlants.SelectedItem.Value.ToString())) _
 

Source File: C:\Inetpub\QSIRegister\QSIStage1.aspx.vb    Line: 552

Stack Trace:


[NullReferenceException: Object reference not set to an instance of an object.]
   ReadymixQSI_ASPNET.QSIStage1.SetMgrs() in C:\Inetpub\QSIRegister\QSIStage1.aspx.vb:552
   ReadymixQSI_ASPNET.QSIStage1.drpCells_SelectedIndexChanged(Object sender, EventArgs e) in C:\Inetpub\QSIRegister\QSIStage1.aspx.vb:601
   ReadymixQSI_ASPNET.QSIStage1.Page_Load(Object sender, EventArgs e) in C:\Inetpub\QSIRegister\QSIStage1.aspx.vb:290
   System.Web.UI.Control.OnLoad(EventArgs e) +131
   System.Web.UI.Control.LoadRecursive() +65
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2427

 


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Version Information: Microsoft .NET Framework Version:2.0.50727.5448; ASP.NET Version:2.0.50727.5420
0
shanthi_joseph
Asked:
shanthi_joseph
1 Solution
 
Dennis AriesCEO @ Arkro ITCommented:
Several options come to mind here:
Is there a selected item?  Has the regioncode been set?

Assuming you cannot use breakpoints: for debugging,  create several helper variables and set them to the values you use.
That way you will see which item gives you the problem and add checks accordingly to overcome the issue.
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p_davisCommented:
you should still, probably, make sure to check that selecteditem has a value before referencing it.

drpRegions.SelectedItem.Value.ToString())
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Craig WagnerSoftware ArchitectCommented:
As the other responders have indicated, there are several things in that line that could be null.

If ((plantRowItem.RegionCode.ToString() = drpRegions.SelectedItem.Value.ToString()) _

plantRowItem could be null
RegionCode could be null
drpRegions could be null
SelectedItem could be null
Value could be null

Use the debugger and check each of the above values to figure out which one of them is actually causing the exception.
0
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shanthi_josephAuthor Commented:
I am not able to use object as a parameter in MsgBox. How do we check if the object is null?
0
 
shanthi_josephAuthor Commented:
I do not require a solution for this problem.
0
 
shanthi_josephAuthor Commented:
I do not require a solution to this problem.
0

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