如何使用动态创建的控件进行部分缓存？

Question

我有一个用PartialCaching属性声明的控件，如下所示：

[PartialCaching(60 * 60 * 12)]
public class MyControl : Control {
    // control contents ...
}

但是我使用new关键字在代码中创建它。问题是如果控件在缓存中，我下次不能再次创建控件，但我需要将控件添加到页面层次结构中，否则不会呈现任何内容。我在伪代码中需要的是这样的：

if (myControlIsCached) {
    var ctl = ???; // something that represents the cached control
                   // e.g. could be: new LiteralControl( myControlCachedData )
    this.Controls.Add( ctl );
}
else {
    var ctl = new MyControl();
    // setup control ...
    this.Controls.Add( ctl );
}

这样做的正确方法是什么？

谢谢大家。

Answer 1

我相信你正在寻找这样的事情：

Control possiblyCachedControl = LoadControl("path to control");
MyControlType control = null;
if (possiblyCachedControl is MyControlType)
{
    //control wasn't cached
    control = possiblyCachedControl as MyControlType;
}
else if (possiblyCachedControl is PartialCachingControl && ((PartialCachingControl)possiblyCachedControl).CachedControl != null)
{
    //control was cached
    control = (MyControlType)((PartialCachingControl)possiblyCachedControl).CachedControl;
}
if (control != null)
{
    //use the control
}