Question

Firstly could someone please be kind enough to comment on why Microsoft might have chosen to make the ASP.NET button control render an <input type='button' /> tag rather than a <button /> tag? I have seen a number of issues (particularly when creating jQuery buttons with no text and just icons) as a result of this.

Secondly I am attempting to create my own custom button output by overriding the Render() event and am having a bit of difficulty trying to understand how to go about changing the output that is provided by this event.

If I look at the HtmlTextWriter that is provided as the parameter to the Render() event I can see it contains a protected property TagKey = Input {47}, is it possible to simply modify this property somehow and change it to a Button or do I need to create a new instance of the HtmlTextWriter and populate it all from the start? If so, could anyone provide some guidance as to how this would typically be done and if there are any special considerations I need to make to ensure that my derived button class is functionally equivalent to the original (excluding the html)?

<Assembly: TagPrefix("MyCompany", "MyCustomButton")> 
Public Class MyButton
    Inherits Button

    Protected Overrides Sub OnPreRender(e As System.EventArgs)
        MyBase.OnPreRender(e)
    End Sub

    Protected Overrides Sub Render(writer As System.Web.UI.HtmlTextWriter)
        'writer.TagKey = Input {47}
        MyBase.Render(writer)
    End Sub
End Class

Answer 1

No idea on Microsoft’s decision, but for the TagKey, you just need to override the TagKey property and return HtmlTextWriterTag.Button. You will also want to override the AddAttributesToRender method and not call the base method so that it wouldn’t output the type="button" attribute.