Category Archives: ASP.NET

UltraWebGrid: “Input string was not in a correct format” error while setting width of a column

Infragistics UltraWebGrid allows you to set width of a column in client-side JavaScript, you can do it using code similar to this:

igtbl_getGridById('xmyGrid').Bands[0].Columns[3].setWidth(someValue)

But, while executing this code on the client, you may get a nasty surprise by getting following error from the server:

Input string was not in a correct format.
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.FormatException: Input string was not in a correct format.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[FormatException: Input string was not in a correct format.]
System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal) +10163939
System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info) +207
Infragistics.WebUI.UltraWebGrid.StateChangeProcessor.ProcessChanges() +6230
Infragistics.WebUI.UltraWebGrid.UltraWebGrid.ProcessChanges(StateChanges stateChanges, Boolean fireEvents) +701
Infragistics.WebUI.UltraWebGrid.UltraWebGrid.LoadPostData(String postDataKey, NameValueCollection values) +7580
System.Web.UI.Page.ProcessPostData(NameValueCollection postData, Boolean fBeforeLoad) +945
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2071

Now, you do know that your someValue is definitely a number, why this error then? Let alone – why client-size resize causes a server call? But I will leave this to Infragistics. Actual cause of the error – number not being Integer. If you change the code from above to

igtbl_getGridById('xmyGrid').Bands[0].Columns[3].setWidth(Math.ceil(someValue))

it will execute without any errors. Go figure.

Solution for “Operation is not valid due to the current state of the object” error

Typically this happens when AJAX controls are involved (Microsoft’s UpdatePanel or others that utilize AJAX POST requests.) The error may be displayed outright or, if nothing is shown on the UI – logged in the Event Viewer. In any case you will get a message similar to:

0x800a139e – Microsoft JScript runtime error: Sys.WebForms.PageRequestManagerServerErrorException: Operation is not valid due to the current state of the object

Issue happens because Microsoft Security Update MS11-100 limits number of keys in Forms collection during HTTP POST request. To alleviate this problem you need to increase that number.

This can be done in your application Web.Config in the <appSettings> section (create the section directly under <configuration> if it doesn’t exist). Add 2 lines similar to the lines below to the section:

<add key="aspnet:MaxHttpCollectionKeys" value="2000" /">
<add key="aspnet:MaxJsonDeserializerMembers" value="2000" /">

The above example set the limit to 2000 keys. This will lift the limitation and the error should go away.

Regenerate JavaScript function code in ASP.NET partial postback after initial load

ASP.NET has a handy way of generating client side JavaScript code, but using it can be sometimes unpredictable. For example your client-side script needs to call function MyAlert, but the function itself is generated server-side on page load:

ClientScript.RegisterStartupScript(Me.GetType, "JSCode", _
                  "function MyAlert() {alert('This is the FIRST call')}", True)

Function is generated, and in due time, when needed is called by the client and the message “This is the FIRST call” is displayed. All is well.

Now, your page also has an UpdatePanel, and during a partial postback you need to modify that client-side function:

ScriptManager.RegisterStartupScript(Me, Me.GetType, "JSCode", _
                  "function MyAlert() {alert('This is the SECOND call')}", True)

In due time, when again needed by client code, function MyAlert is called and the message (wait for it, you’re in for a surprise) “This is the FIRST call” is displayed again. Originally generated function is called and second generation is ignored. Continue reading →

UltraWebGridExcelExporter: Export more than 65536 rows

When exporting data from Infragistics UltraWebGrid into Excel using UltraWebGridExcelExporter ordinary a very basic code similar to this is used:

'
' define Exporter "xMyExporter"
' define UltraWebGrid "xMyGrid" and load grid with data, then:
'
xMyExporter.ExportMode = UltraWebGrid.ExcelExport.ExportMode.Download
xMyExporter.Export(xMyGrid)

That’s it. But, if your data exceed 65536 rows you will get an error:

System.InvalidOperationException: The maximum number of rows in an excel worksheet with the current format is: 65536

This is not Excel Exporter limitation. Continue reading →

(Possible) solution for MSChart ArgumentException The image is not found error

If you’re using Microsoft’s .NET charting control on your ASP.NET pages you may receive an annoying error

[ArgumentException]: The image is not found. at
System.Web.UI.DataVisualization.Charting.ChartHttpHandler.ProcessSavedChartImage(HttpContext context) at
System.Web.UI.DataVisualization.Charting.ChartHttpHandler.System.Web.IHttpHandler.ProcessRequest(HttpContext context) at
System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

I could be intermittent, sometimes happen, sometimes not. In your web.config you already set your temp images to be stored as files and not deleted after serving:

<add key="ChartImageHandler" value="storage=file;timeout=20;url=~/temp/;deleteAfterServicing=false" />

as well as trying other remedies and nothing helps.

One possible solution is, while still using file temp storage, instead of indicating relative path via url property set it to absolute path via dir property:

<add key="ChartImageHandler" value="storage=file;timeout=20;dir=C:\TEMP;deleteAfterServicing=false" />

In the example above C:\TEMP is an absolute path to the temp folder on the Web Server. In your case it could be different; in multi-server (WebFarm) environment it should be a network share, accessible by all servers.

‘this.Column.Band’ is null or not an object error in UltraWebGrid filtering

When you filter Infragistics UltraWebGrid by clicking Filter icon in the column header – dropdown with filter values appears. Normally if you click elsewhere on the page – dropdown disappears. But sometimes it doesn’t, for example if you click an element that invokes a JavaScript function. Filter dropdown stays open and this could cause problems – when grid refreshes (and possibly other actions are performed) error is thrown:

‘this.Column.Band’ is null or not an object

The solution to this is to close filter dropdown ourselves. Put these lines into your client-side code whenever clicking outside the filter doesn’t close it:

var aGridCols = igtbl_getGridById('xMyGrid').Bands[0].Columns
   for (var I = 0; I < aGridCols.length; I++)
      aGridCols[I].showFilterDropDown(false);

Here we’re looping thru grids column collection (This example assumes grid is in Flat or OutlookGroupBy mode, if your grid is hierarchical, you will have to loop thru band collection as well). For every column we pass False to showFilterDropDown method which (probably showing Infragistics cute sense of humor) hides filter dropdown if it is open. If dropdown is hidden for the column already – nothing happens.

As a result opened filter dropdown is now always closed prior to previously offending action and the error doesn’t happen.

Speed up UltraWebGrid rendering on rebind

If you’re using Infragistics UltraWebGrid with it’s property Browser="Xml", you may find yourself living in a shotgun shack in a strange situation: When grid is rebinding – it takes (comparatively) short time to do server-side processing and then a very long time to render grid in the browser.

In my case it was most felt when grid (which had ViewType="OutlookGroupBy") was initially grouped with a lot of data in each group and then ungrouped back into flat view when user dragged last group column out. Using IE9 built-in developer tools I ran JavaScript profiler I found that culprit was Infragistics JS function “disposeNode” which was called numerous times and had worst both inclusive and exclusive execution time. Continue reading →

SSRS viewer doesn’t work on IIS7 64bit

If you’re developing an ASP.NET application that utilizes Microsoft’s SSRS ReportViewer control, you may experience a weird behavior while trying to use it on 64 bit version of IIS7 (Windows Server 2008 or Windows 7) – nothing is displayed in the main report area and even icons, such as Print, Export aren’t rendering.

One possible cause for this – your application is using Application Pool with 32bit mode enabled. If so – disable it or switch to a different application pool. Chances are this will fix the above issue.

WHDG: Correctly detect Async Callback

When using Infragistics WebHierarchicalDataGrid often there’s a need to detect grid’s async callback (for example we need to rebind the grid if it performs AJAX paging or expanding children). For flat WebDataGrid it was suggested to use grid’s RunBot.IsCallback property:

If xMyGrid.RunBot.IsCallback Then
   'Perform some operations for grid's async callback
End If

Now, WHDG also has RunBot.IsCallback property, but the above code always returns False for it. I know I’ve seen this before – a situation where a property doesn’t work on WHDG control itself, but works on the WHDG’s GridView object. Sensing a pattern I modified the code above for WHDG:

If xMyGrid.GridView.RunBot.IsCallback Then
   'Perform some operations for grid's async callback
End If

And bingo! Now Async callback is detected correctly.

UPDATE 4/27/2012: Turned out the above method doesn’t always work either. (To Infragistics stuff, if anybody happened to read this: The scenario above happens with WHDG in manual load on demand mode when grid’s RowIslandPopulating event is handled and ContainerGrid is created on demand and bound to data retrieved from the Database). The above method works when rows of the top level expanded (xMyGrid.GridView.RunBot.IsCallback is True) but fails if child rows are expanded to show grandchildren (in that case xMyGrid.GridView.RunBot.IsCallback is False).

We need another more reliable way to detect callback, no matter what caused it. And we can do that by checking HTTP Request. If it’s an Infragistics callback it will have a Form parameter with key like "__IGCallback************". So the code to always detect the callback correctly is:

If Request.Form.AllKeys.Any(Function(S As String) S IsNot Nothing AndAlso S.StartsWith("__IGCallback")) Then
   'Perform some operations for grid's async callback
End If

WebDataTree returns multiple selected nodes in single-select mode

This could be a bug in Infragistics WebDataTree control or it could be a very specific scenario (maybe it’s even by design, I don’t know) but here’s a weird behavior that I encountered. Using following code in WebDataTree’s event handler (oh and by the way, tree control is in a single-select mode):

Protected Sub xMyTree_SelectionChanged(ByVal sender As Object, ByVal e As NavigationControls.DataTreeSelectionEventArgs) Handles MyTree.SelectionChanged
   if e.NewSelectedNodes(0).Text = "Some Value"
      'do something with newly selected tree node
   end if
End Sub

I intended to use newly selected node to perform some operations. To my surprise e.NewSelectedNodes(0) referred to previously selected node (despite the name of the property) and newly selected value were located in e.NewSelectedNodes(1)! So the quick workaround was to use slightly modified code:

Protected Sub xMyTree_SelectionChanged(ByVal sender As Object, ByVal e As NavigationControls.DataTreeSelectionEventArgs) Handles MyTree.SelectionChanged
   if e.NewSelectedNodes(e.NewSelectedNodes.Count-1).Text = "Some Value"
      'do something with newly selected tree node
   end if
End Sub

This way it will always get latest selected node and the solution is universal. If the bug described above occurs – code will grab e.NewSelectedNodes(1) (because Count = 2). If the tree behaves as expected – code will get grab e.NewSelectedNodes(0) (because Count = 1)