Hi ,
i too got the same problem, i try to render a treecontrol and pass
the html to some other mehthod, it give object set to null exception, i
tried many things but cannot do it, i tried to replace
get_spacerImageurl() but no use. Did anyone have solution for this problem
part of my code is
private string RenderTree()
{
TreeView Tview = new TreeView();
TreeNode tnode = new TreeNode("Node1", "1");
Tview.Nodes.Add(tnode);
Tview.ID = "Tree1";
StringBuilder sb = new StringBuilder();
StringWriter sw = new StringWriter(sb);
HtmlTextWriter htmlTW = new HtmlTextWriter(sw);
Tview.RenderControl(htmlTW);
return sb.ToString();
}
and stack trace is [NullReferenceException: Object reference not set to an
instance of an object.]
System.Web.UI.Control.get_SpacerImageUrl() +50
System.Web.UI.WebControls.TreeView.RenderBeginTag(HtmlTextWriter writer)
+202
System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer) +31
System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer,
ControlAdapter adapter) +74
System.Web.UI.Control.RenderControl(HtmlTextWriter writer,
ControlAdapter adapter) +291
System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +49
TreeviewRender.RenderTree() in
d:\TestProject\TestProject\TreeviewRender.aspx.cs:30
TreeviewRender.Page_Load(Object sender, EventArgs e) in
d:\TestProject\TestProject\TreeviewRender.aspx.cs:17
System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o,
Object t, EventArgs e) +31
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender,
EventArgs e) +68
System.Web.UI.Control.OnLoad(EventArgs e) +88
System.Web.UI.Control.LoadRecursive() +74
System.Web.UI.Page.ProcessRequestMain(Boolean
includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3030
Gaurav Vaish (EduJini.IN) said:
Cryptic only with the exception that SpacerImageUrl is missing.
Provided any value to it?
Or may be something coming out of MyControl.cs
Mail me the relevant code (with aspx) at
gaurav~DOT~vaish[at]gmail~DOT~com... not sure, but probably may be of
some help.
--
Happy Hacking,
Gaurav Vaish
http://www.mastergaurav.org
http://www.edujini.in
-------------------
Jonas said:
Hi,
here is the exception info:
System.NullReferenceException was unhandled by user code
Message="Object reference not set to an instance of an object."
Source="System.Web"
StackTrace:
at System.Web.UI.Control.get_SpacerImageUrl()
at
System.Web.UI.WebControls.TreeView.RenderBeginTag(HtmlTextWriter
writer)
at System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter
writer)
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)
at WebControlLibrary1.MyControl.RenderContents(HtmlTextWriter
output) in C:\Work\WebSite1\WebControlLibrary1\MyControl.cs:line 27
at System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter
writer)
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)
at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter
writer, ICollection children)
at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
at
System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter
writer)
at
System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter
writer)
at System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter
output)
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)
at
System.Web.UI.HtmlControls.HtmlForm.RenderControl(HtmlTextWriter
writer)
at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter
writer, ICollection children)
at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
at System.Web.UI.Control.Render(HtmlTextWriter writer)
at System.Web.UI.Page.Render(HtmlTextWriter writer)
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)
at System.Web.UI.Page.ProcessRequestMain(Boolean
includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)