Is there a difference in behavior between adding a control to the ASPX page directly and loading a control programmatically and adding to a placeholder?
The control inherits from System.Web.UI.WebControls.DataBoundControl.
The reason I ask is that I have a control that works when I add it to the ASPX page like so:
... <blah:GoogleMap ID='GoogleMap1' runat='server' Width='640px' Height='600px' ... DataSourceID='_odsMarkers' DataAddressField='Address' DataTextField='Description'> </blah:GoogleMap> ...
But not when I use the following in a codebehind page:
GoogleMap map = (GoogleMap)this.LoadControl(typeof(GoogleMap), new object[] { }); //... set properties this.placeholder1.Controls.Add(map); //add to placeholder
Anyone have any ideas why this might be the case?
The control tree ends up the same if you define in markup or add programmatically. However there is plenty of room for the control implementor to screw up along the way.
You can go look how ASP.NET compiles the aspx:
The timing when the control is added to the page might be an issue. The usual pattern is add the control in an overload of the CreateChildControls method. If the control needs to resolve viewstate you need to make sure this is called during init, e.g. by calling EnsureChildControls.
Adding to ninja’s debbugging hint. Does it make any difference if you add a label the same way. Does it show up?