Export To Excel - Null Reference Error

[GreggBreton]

Hello,

I downloaded the following solution file
http://forums.arcgis.com/threads/45538-How-to-make-Export()-is-work-with-ArcGIS-API-for-Silverlight!


Export.zip
QueryWithoutMap.zip

Executed and  queried the default "New" clicked the export button and works fine
Then tried "S", returned records and tried to export and received "Null Reference Exception"

Use the new keyword to create an object instance
Check to determine if the object is null before calling the method


  private static string GetValue(FrameworkElement frameworkElement)
        {
            return frameworkElement is TextBlock ? (frameworkElement as TextBlock).Text : frameworkElement.ToString();
        }

If someone could illustrate how the above would be written to avoid the null exception error

Thank you

[deleted-user-ATjHIWsdQYmT]

Gregg-
Try:

private static string GetValue(FrameworkElement frameworkElement){ return frameworkElement is TextBlock & (frameworkElement != null) ? (frameworkElement as TextBlock).Text : frameworkElement.ToString();}

This should trap if your frameworkElement is NOT null

[GreggBreton]

Andrew -

I still receive the same Null Exception?

[DominiqueBroux · Accepted solution]

Try:

private static string GetValue(FrameworkElement frameworkElement) {     return frameworkElement == null ? null          :( frameworkElement is TextBlock ? (frameworkElement as TextBlock).Text : frameworkElement.ToString()); }

[JoeHershman]

Nothing incorrect about the above code but I think this is a bit easier to read and I think should work.

        private static string GetValue(FrameworkElement frameworkElement)
        {
            var textBlock = frameworkElement as TextBlock;
            if ( textBlock == null ) return null;


            return textBlock.Text;
        }

[GreggBreton]

Yes, that did the trick

It allowed me to download the file, but when I open the csv file it displays the following:

File is in a different file format than specified by the extension

[ATTACH=CONFIG]16753[/ATTACH]

Excel has detected that the file is a SYLK file, but cannot load it, either the file has errors or is not in SYLK format

[ATTACH=CONFIG]16755[/ATTACH]

After the above messages, the file opens and looks fine.

Would the errors be caused by the REST service data not being in correct format? The script trying to conform to the csv format? or something else that you may have run into..

Thank you Dominique

[GreggBreton]

Yes, that did the trick

It allowed me to download the file, but when I open the csv file it displays the following:

File is in a different file format than specified by the extension

[ATTACH=CONFIG]16756[/ATTACH]

Excel has detected that the file is a SYLK file, but cannot load it, either the file has errors or is not in SYLK format

[ATTACH=CONFIG]16757[/ATTACH]

After the above messages, the file opens and looks fine.

Would the errors be caused by the REST service data not being in correct format? The script trying to conform to the csv format? or something else that you may have run into..

Thank you Dominique

[deleted-user-ATjHIWsdQYmT]

Yes, that did the trick

It allowed me to download the file, but when I open the csv file it displays the following:

File is in a different file format than specified by the extension

[ATTACH=CONFIG]16756[/ATTACH]

Excel has detected that the file is a SYLK file, but cannot load it, either the file has errors or is not in SYLK format

[ATTACH=CONFIG]16757[/ATTACH]

After the above messages, the file opens and looks fine.

Would the errors be caused by the REST service data not being in correct format? The script trying to conform to the csv format? or something else that you may have run into..

Thank you Dominique

Gregg,
Check out this link:
http://support.microsoft.com/kb/323626

If your first  field name is "ID", try trapping it in your export code by changing it to "id" or adding an apostraphe like the article says.  Another workaround would be to hide the "ID" field from your map service unless it's necessary.

[GreggBreton]

I will follow up on thread and give it a try


Thank you

[deleted-user-ATjHIWsdQYmT]

I will follow up on thread and give it a try


Thank you

Gregg, Quick solution - change the Header text of the first column from "ID" to something else.  It'll solve the problem.