Web Control development essay (3): A Preliminary Study on the Rendering Method of Control and WebControl

Control
:

Render
:
WebControl inherited from
Control class, And overwrites
Render
Method. This method should be overwritten by subclass.

RenderChildren: child node used to present the control
(Usually
HTML)

RenderControl
: Used to render controls
(
Is
Control
Object
)

RenderChildren is the rendering control, while
CreateChildControls is mainly used to initialize the child control (note that it is not used to render the child control ).

 

WebControl:
(
Inheritance
Control
Methods
)

About
Render
Several important methods
(
The method parameters are
HtmlTextWriter (related
Three enumeration types:
HtmlTextWriterTag
,
HtmlTextWriterAttribute
,
HtmlTextWriterStyle
))
:

AddAttributesToRender:
The subclass of WebControl should override this method to include the outermost layer for rendering.
HTML Element
Code for HTML attributes
Block.

RenderBeginTag:
The subclass of WebControl should override this method to include the outermost layer for rendering.
Code for opening the HTML Element
Block.

RenderContents:
The subclass of WebControl should override this method to include the outermost layer for rendering.
Nested between opening and closing tags of HTML elements
HTML code block.

RenderEndTag:
The subclass of WebControl should override this method to include the outermost layer for rendering.
Code for disabling HTML elements
Block.

TagKey attribute: Read-only attribute, used to set the outermost layer
HTML Element
HTML element.

Event Call Sequence

1. CreateChildControls
2. OnInit
3. TrackViewState
4. LoadViewState
5. LoadPostData
6. OnLoad
7. RaisePostDataChangedEvent
8. OnBubbleEvent)
9. OnPreRender
10. SaveViewState
11. RenderControl
12. Render
    1. RenderBeginTag
    2. AddAttributesToRender
    3. CreateControlStyle
    4. RenderContents
    5. RenderChildren
    6. RenderEndTag
13. OnUnload