Question

As my title says, I have a set property crash problem.

Here’s the scenario:

1. I have created a simple custom ASP.Net server control that generates some text.
2. I wanted to give design-time property for that text so its style can be accessed by developers from the properties window.
3. All the properties in the properties window are working except the ones with the type System.Web.UI.WebControls.Style that I have created.

Here is my property:

[Bindable(true)]
[Category("Appearance")]
[Description("The style for the header")]
[Localizable(true)]
public Style HeaderTextStyle
{
  get
  {
    Style s = (Style)(ViewState["HeaderTextStyle"] == null ? Styles.defaultHeaderStyle : ViewState["HeaderTextStyle"]);
    return s;
  }

  set
  {
    ViewState["HeaderTextStyle"] = value;
  }
}

Oh and Styles.defaultHeaderStyle is just a property from an internal class that returns a new Style.

Let me point that the hanging/crashing occurs only when I CHANGE the property, so it cannot be from the getter.

I won’t paste my render control because the error occurs even when I’m not rendering anything.

What is it that causes this?

Thank you.

Answer 1

I found the answer to my problem.

You see, the Style class is a property that has sub-properties and it is called a complex property. Complex properties ( a property that has subproperties) need custom state management to use view state. The Style class need design-time attributes to enable persistence within the control’s tags. So what I wrote in my original post will not work.

For complete explanation visit: Server Control Properties Example from MSDN

I managed to implement it using that example. I hope this will be useful to others out there.