How to add css to a asp.net web application

I am starting a new asp.net web app class (using c#). For my first lab I need to create a simple开发者_JAVA技巧 web page with a couple button. I have already made the page with the buttons and text. When you press the button it needs to change the text color using in-line css. How would I go about adding the in-line css to the button. Would I add some sort of C# code in the button to enable css? I am quite confused how to add the css to the web app. Any ideas?

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From your question it sounds like you want to add inline css to some sort of element containing text when you click a Button?

protected void btn_Click(object sender, EventArgs e)
{
   string inlineCss = "your css goes here";

   //I'm assuming the text you want to apply css to is a Label with ID=label
   label.Attributes.Add("style", inlineCss);
}

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Try this on click event

        HtmlLink css = new HtmlLink();    
        css.Href = "css/fancyforms.css";    
        css.Attributes["rel"] = "stylesheet";    
        css.Attributes["type"] = "text/css";    
        css.Attributes["media"] = "all";    
        Page.Header.Controls.Add(css);

If needs inline

        txtmyCtrl.Style.Add(HtmlTextWriterStyle.Color,"#33cc45");