c# NullReferenceException on HtmlTextWriter object in WebControl
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18-10-2022 - |
Frage
Hi I have the following code that sometimes works and sometimes it does not:
protected override void Render(HtmlTextWriter aWriter)
{
// Div
aWriter.RenderBeginTag(HtmlTextWriterTag.Div);
// Table
aWriter.AddAttribute(HtmlTextWriterAttribute.Cellspacing, "0");
aWriter.RenderBeginTag(HtmlTextWriterTag.Table);
aWriter.RenderBeginTag(HtmlTextWriterTag.Tbody);
// Header
aWriter.RenderBeginTag(HtmlTextWriterTag.Tr);
aWriter.AddAttribute(HtmlTextWriterAttribute.Class, "Header1");
aWriter.RenderBeginTag(HtmlTextWriterTag.Td);
aWriter.Write(GetText(24));
aWriter.RenderEndTag();
aWriter.AddAttribute(HtmlTextWriterAttribute.Class, "Header2");
aWriter.RenderBeginTag(HtmlTextWriterTag.Td);
aWriter.Write(GetText(25));
aWriter.RenderEndTag();
aWriter.RenderEndTag(); // Tr
.............
When I run the above code sometimes I get the following error:
Exception type: NullReferenceException
Exception message: Object reference not set to an instance of an object.
at Controls.TestControl.Render(HtmlTextWriter aWriter) in C:\Test\SourceCode\Controls\TestControl.cs:line 60
at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
...
Line 60 is the following:
aWriter.RenderEndTag(); // Tr
I am getting nuts with this because if it crashes, you press refresh and it works. For some reason, aWriter object sets to Null but I cannot find why and it looks somehow random even though it always points to the same line. 80% of the times it works correctly and 20% of the times it crashes but without any pattern.
Any idea on what could be happening?
Thanks!
Keine korrekte Lösung
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