ASP.NET Render 概要
在ASP.NET的生命周期走到Render阶段,Page.ProcessMain方法会调用Page的RenderControl方法,RenderControl方法会调用RenderControlInternal,RenderControlInternal根据该空间否是有ControlAdapter调用不同的呈现方法。RenderControlInternal的方法原型如下:
private void RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
{
if (adapter != null)
{
adapter.BeginRender(writer);
adapter.Render(writer);
adapter.EndRender(writer);
}
else
{
this.Render(writer);
}
}
{
if (adapter != null)
{
adapter.BeginRender(writer);
adapter.Render(writer);
adapter.EndRender(writer);
}
else
{
this.Render(writer);
}
}
默认情况下会执行到Page类的Render方法。
剩下的过程如下:
Page.Render--->Control.Render--->Control.RenderChildren--->Control.RenderChildrenInternal --->control.RenderControl--->Control.RenderControlInternal.
RenderChildrenInternal的方法原型如下:
internal void RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
{
if ((this.RareFields != null) && (this.RareFields.RenderMethod != null))
{
writer.BeginRender();
this.RareFields.RenderMethod(writer, this);
writer.EndRender();
}
else if (children != null)
{
foreach (Control control in children)
{
control.RenderControl(writer);
}
}
}
if ((this.RareFields != null) && (this.RareFields.RenderMethod != null))
{
writer.BeginRender();
this.RareFields.RenderMethod(writer, this);
writer.EndRender();
}
else if (children != null)
{
foreach (Control control in children)
{
control.RenderControl(writer);
}
}
}
Remark:
In the method of RenderChildrenInternal,the argument children with type IConllection will be circulated,to invoke t every control's RenderControl Method.