blocks|key|3162627|text|我说继续使用自定义呈现控件。我发现在大多数情况下，在UserControl中可以更容易地完成和使用合成，但除此之外，您需要有更好的控制程度(双关语意外)，以配得上您自己的呈现策略。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3162628|也许有一些控件足够简单，值得使用复合控件(例如，textbox与基于javascript/dhtml的datepicker相结合)，但除此之外，自定义呈现控件看起来是可行的。|3162629|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

I say go ahead with the custom rendered control. I find that in most cases the composite can be easier done and used in a UserControl, but anything beyond that and you'd need to have a finer degree of control (pun unintended) to merit your own rendering strategy.

There maybe controls that are simple enough to merit a composite (e.g., a textbox combined with a javascript/dhtml based datepicker, for example) but beyond that one example, it looks like custom rendered controls are the way to go.

blocks|key|367199|text|我经常使用复合控件。只需为每个控件分配一个CssClass并使用样式表，而不是覆盖Render或RenderContents。对于多个Controls.Add，我使用一个扩展方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|367200|//Controls.Add(c1,+c2,+c3)
static+void+Add(this+ControlCollection+coll,+params+Control[]+controls)
+{+foreach(Control+control+in+controls)+coll.Add(control);
+}|code-block|syntax|javascript|367201|为了更快更脏的渲染，我使用了类似这样的东西：|367202|writer.Render(@"<table>
+++++++++++++++++++<tr><td>{0}</td></tr>
+++++++++++++++++++<tr>
+++++++++++++++++++++++<td>",+Text);
control1.RenderControl(writer);
writer.Render("</td></tr></table>");|367203|为了初始化控件属性，我使用属性初始化器语法：|367204|childControl+=+new+Control+{++ID="Foo"
++++++++++++++++++++++++++++,+CssClass="class1"
++++++++++++++++++++++++++++,+CausesValidation=true;
+++++++++++++++++++++++++++};|367205|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

I often use composite controls. Instead of overriding Render or RenderContents, just assign each Control a CssClass and use stylesheets. For multiple Controls.Add, I use an extension method:

<pre><code>//Controls.Add(c1, c2, c3)
static void Add(this ControlCollection coll, params Control[] controls)
 { foreach(Control control in controls) coll.Add(control);
 }
</code></pre>

For quick and dirty rendering, I use something like this:

<pre><code>writer.Render(@"&lt;table&gt;
 &lt;tr&gt;&lt;td&gt;{0}&lt;/td&gt;&lt;/tr&gt;
 &lt;tr&gt;
 &lt;td&gt;", Text);
control1.RenderControl(writer);
writer.Render("&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;");
</code></pre>

For initializing control properties, I use property initializer syntax:

<pre><code>childControl = new Control { ID="Foo"
 , CssClass="class1"
 , CausesValidation=true;
 };
</code></pre>

blocks|key|366855|text|在您有一个大型web应用程序并希望在许多地方重用大块数据块的情况下，使用自定义复合控件是有意义的。然后，您只需添加正在开发的控件的子控件，而不是重复添加。在我最近参与的一个大型项目中，我们做了以下工作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|366856|366857|每个复合控件都有一个容器。用作控件内所有内容的包装。|unordered-list-item|366858|每个复合控件都有一个模板。只包含模板标记的ascx文件(没有<%25Control%25>指令)。|366859|容器(本身是一个控件)是从模板初始化的。|366860|容器公开模板中所有其他控件的属性。|366861|在复合控件中仅使用this.Controls.Add(the_container)。|366862|366863|实际上，您需要一个基类来负责使用指定的模板初始化容器，并在模板中找不到控件时抛出异常。当然，在小型应用程序中，这可能是一种过度的杀伤力。如果您没有可重用的代码和标记，并且只想编写简单的控件，那么最好使用用户控件。|366864|entityMap^0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|T|8|@]|9|@]|A|$]]|$1|C|3|D|5|E|7|U|8|@]|9|@]|A|$]]|$1|F|3|G|5|E|7|V|8|@]|9|@]|A|$]]|$1|H|3|I|5|E|7|W|8|@]|9|@]|A|$]]|$1|J|3|K|5|E|7|X|8|@]|9|@]|A|$]]|$1|L|3|M|5|E|7|Y|8|@]|9|@]|A|$]]|$1|N|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|10|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|R|$]]

Using custom composite controls has a point in a situation where you have a large web application and want to reuse large chunks in many places. Then you would only add child controls of the ones you are developing instead of repeating yourself.
On a large project I've worked recently what we did is the following:

<ul>
<li>Every composite control has a container. Used as a wrapped for everything inside the control.</li>
<li>Every composite control has a template. An ascx file (without the &lt;%Control%> directive) which only contains the markup for the template.</li>
<li>The container (being a control in itself) is initialized from the template.</li>
<li>The container exposes properties for all other controls in the template.</li>
<li>You only use this.Controls.Add([the_container]) in your composite control.</li>
</ul>

In fact you need a base class that would take care of initializing a container with the specified template and also throw exceptions when a control is not found in the template. Of course this is likely to be an overkill in a small application. If you don't have reused code and markup and only want to write simple controls, you're better off using User Controls.

blocks|key|365450|text|下面是我用于自定义渲染的另一个扩展方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|365451|+public+static+void+WriteControls
++++++++(this+HtmlTextWriter+o,+string+format,+params+object[]+args)
+{+
++++const+string+delimiter+=+"<2E01A260-BD39-47d0-8C5E-0DF814FDF9DC>";
++++var+controls++=+new+Dictionary<string,Control>();

++++for(int+i+=0;+i+<+args.Length;+%2B%2Bi)
++++{+
+++++++var+c+=+args[i]+as+Control;+
+++++++if+(c==null)+continue;
+++++++var+guid+=+Guid.NewGuid().ToString();
+++++++controls[guid]+=+c;
+++++++args[i]+=+delimiter%2Bguid%2Bdelimiter;
++++}

++++var+_strings+=+string.Format(format,+args)
+++++++++++++++++++++++++.Split(new+string[]{delimiter},
++++++++++++++++++++++++++++++++StringSplitOptions.None);
++++foreach(var+s+in+_strings)
++++{+
+++++++if+(controls.ContainsKey(s))+
+++++++++++controls[s].RenderControl(o);
+++++++else+
+++++++++++o.Write(s);
++++}
}|code-block|syntax|javascript|365452|然后，为了在RenderContents()方法中呈现自定义组合，我编写了以下代码：|365453|protected+override+void+RenderContents(HtmlTextWriter+o)
{+
++++o.WriteControls
+++++++++(@"<table>
+++++++++++++++<tr>
++++++++++++++++++++<td>{0}</td>
++++++++++++++++++++<td>{1}</td>
+++++++++++++++</tr>
+++++++++++++</table>"
++++++++++++,Text
++++++++++++,control1);
+}|365454|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Here's another extension method that I use for custom rendering:

<pre><code> public static void WriteControls
 (this HtmlTextWriter o, string format, params object[] args)
 { 
 const string delimiter = "&lt;2E01A260-BD39-47d0-8C5E-0DF814FDF9DC&gt;";
 var controls = new Dictionary&lt;string,Control&gt;();

 for(int i =0; i &lt; args.Length; ++i)
 { 
 var c = args[i] as Control; 
 if (c==null) continue;
 var guid = Guid.NewGuid().ToString();
 controls[guid] = c;
 args[i] = delimiter+guid+delimiter;
 }

 var _strings = string.Format(format, args)
 .Split(new string[]{delimiter},
 StringSplitOptions.None);
 foreach(var s in _strings)
 { 
 if (controls.ContainsKey(s)) 
 controls[s].RenderControl(o);
 else 
 o.Write(s);
 }
}
</code></pre>

Then, to render a custom composite in the RenderContents() method I write this:

<pre><code>protected override void RenderContents(HtmlTextWriter o)
{ 
 o.WriteControls
 (@"&lt;table&gt;
 &lt;tr&gt;
 &lt;td&gt;{0}&lt;/td&gt;
 &lt;td&gt;{1}&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;"
 ,Text
 ,control1);
 }
</code></pre>

blocks|key|365496|text|罗伯，你说得对。我提到的方法是一种混合方法。拥有ascx文件的好处是，在我见过的每个项目中，设计人员都会感到最舒服的是编辑实际的标记，以及你和设计师可以单独工作的ascx。如果您不打算稍后对控件本身进行实际的CSS/标记/设计更改，则可以使用自定义呈现控件。正如我所说的，我的方法只适用于更复杂的场景(而这些场景可能就是您需要设计师的地方：)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|365497|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Rob, you are right. The approach I mentioned is kind of a hybrid. The advantage of having ascx files around is that on every project I've seen, designers would feel most comfortable with editing actual markup and with the ascx you and a designer can work separately. If you don't plan on actual CSS/markup/design changes on the controls themselves later, you can go with a custom rendered control. As I said, my approach is only relevant for more complicated scenarios (and these are probably where you need a designer :))

blocks|key|3162934|text|您也许能够利用此技术来简化设计时：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3162935|http://aspadvice.com/blogs/ssmith/archive/2007/10/19/Render-User-Control-as-String-Template.aspx|offset|length|3162936|基本上，您在运行时使用LoadControl方法创建用户控件的实例，然后递给它某种状态包，然后将其附加到控件树。因此，复合控件的功能实际上更像是一个控制器，而.ascx文件则更像是一个视图。|3162937|这将省去您必须实例化整个控件树并在C#中设置控件样式的麻烦！|3162938|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|2O|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@$D|S|E|T|1|U]]|A|$]]|$1|F|3|G|5|6|7|V|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|W|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|X|8|@]|9|@]|A|$]]]|K|$L|$5|M|N|O|A|$P|C]]]]

You might be able to make use of this technique to make design-time easier:

<a href="http://aspadvice.com/blogs/ssmith/archive/2007/10/19/Render-User-Control-as-String-Template.aspx" rel="nofollow noreferrer">http://aspadvice.com/blogs/ssmith/archive/2007/10/19/Render-User-Control-as-String-Template.aspx</a>

Basically you create an instance of a user control at runtime using the LoadControl method, then hand it a statebag of some kind, then attach it to the control tree. So your composite control would actually function like more of a controller, and the .ascx file would be like a view.

This would save you the trouble of having to instantiate the entire control tree and style the control in C#!

<h2>Summary</h2>
Hi All, 
OK, further into my adventures with custom controls...
In summary, here is that I have learned of three main &quot;classes&quot; of custom controls. Please feel free to correct me if any of this is wrong!
<ol>
<li>UserControls - Which inherit from UserControl and are contained within an ASCX file. These are pretty limited in what they can do, but are a quick and light way to get some UI commonality with designer support.</li>
<li>Custom Composite Controls - These are controls that inherit from WebControl where you add pre-existing controls to the control within the CreateChildControls method. This provides great flexibility, but lack of designer support without additional coding. They are highly portable though since they can be compiled into a DLL.</li>
<li>Custom Rendered Controls - Similar to Custom Composite Controls, these are added to a Web Control Library project. The rendering of the control is completely controlled by the programmer by overriding the Render method.</li>
</ol>
<h2>My Thoughts..</h2>
OK, so while playing with custom composites, I found the following:
<ul>
<li>You have little/no control over the HTML output making it difficult to &quot;debug&quot;.</li>
<li>The CreateChildControls (and subsequent methods) can get real busy with Controls.Add(myControl) everywhere.</li>
<li>I found rendering tables (be it for layout or content) to be considerably awkward.</li>
</ul>
<h2>The Question(s)..</h2>
So, I admit, I am new to this so I could be way off-base with some of my points noted above..
<ul>
<li>Do you use Composites?</li>
<li>Do you have any neat tricks to control the HTML output?</li>
<li>Do you just say &quot;to hell with it&quot; and go ahead and create a custom rendered control?</li>
</ul>
Its something I am keen to get really firm in my mind since I know how much good control development can cut overall development time.
I look forward to your answers ^_^

ASP.NET Custom Controls - Composites

容器

摘要大家好，好的，继续我的自定义控件之旅……总而言之，我已经了解了三个主要的自定义控件“类”。如果这里有任何错误，请随时纠正我！UserControls -从UserControl继承并包含在一个ASCX文件中。这些控件的功能非常有限，但它们是获得设计器support.Custom复合控件的一些UI通用性的快速而简单的...

问ASP.NET自定义控件-复合控件
EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问ASP.NET自定义控件-复合控件EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问ASP.NET自定义控件-复合控件
EN