I want send to output CSS info in style blocks
protected override void RenderContents(HtmlTextWriter output)
{
...
output.Write("<style> .... ");
}
But this block cant be nested in div block .I must place it in head.How can I do it or is there another approach?
The this.Page.Header.Stylesheet.CreateStyleRule method lets you add styles to the <head>. However, the CSS attributes that you can specify are limited to those supported by the Style class. (You can derive your own class from Style if you need additional attributes.)
C# example:
protected override void OnPreRender(EventArgs e)
{
base.OnPreRender(e);
// Create a Style object for the body of the page.
Style bodyStyle = new Style();
bodyStyle.ForeColor = System.Drawing.Color.Blue;
bodyStyle.BackColor = System.Drawing.Color.LightGray;
// Add the style rule named bodyStyle to the header
// of the current page. The rule is for the body HTML element.
this.Page.Header.StyleSheet.CreateStyleRule(bodyStyle, null, "body");
}
Derive from System.Web.UI.Control directly and override the Render method, instead of deriving from (what I assume is) System.Web.IO.WebControls.WebControl.
来源：https://stackoverflow.com/questions/13184276/send-style-info-from-custom-server-asp-element