ASP.NET自定義控件組件開發 第二章 繼承WebControl的自定義控件（一）

到現在為止，我已經寫了三篇關於自定義控件開發的文章，很感謝大家的支持！不知道大家對我講的 方式有什麼好的建議，我盡量使自定義控件的技術讓更多的程序員同胞接受。好了，開發開始了！

本章還是延續上章的例子，開發一個CreditCardForm控件。

其實本章也不難，相信大家看完後，也覺得很簡單！

我們首先開談談繼承Control和WebControl的區別：其實二者最大的區別就是在，如果我們開發的控件 繼承WebControl，那麼我們的控件就支持更多的CSS樣式。而繼承於Control的自定義控件的樣式相對就少 些。

其實還有一個區別就在開發的規范上。我們來簡單的看看上一章的自定義控件的代碼，主要來看看 Render方法中的代碼：大家只掃一眼就可以了。

1 protected override void Render(HtmlTextWriter writer)
  2         {
  3             //顯示table標記
  4             writer.AddStyleAttribute(HtmlTextWriterStyle.Width, "287px");
  5             writer.AddStyleAttribute(HtmlTextWriterStyle.Height, "128px");
  6             writer.AddStyleAttribute(HtmlTextWriterStyle.BorderWidth, "0");
  7             writer.AddAttribute(HtmlTextWriterAttribute.Id, "mytable");
  8             writer.RenderBeginTag(HtmlTextWriterTag.Table);
  9
 10             //顯示table類的標記 包含 tr ，td 還有一些textbox,下拉框等
 11             writer.RenderBeginTag(HtmlTextWriterTag.Tr);
 12
 13             writer.RenderBeginTag(HtmlTextWriterTag.Td);
 14             writer.Write(PaymentMethodText);
 15             writer.RenderEndTag();
 16
 17             writer.RenderBeginTag(HtmlTextWriterTag.Td);
 18             writer.AddAttribute(HtmlTextWriterAttribute.Name, 

"PaymentMethod");
 19             writer.AddAttribute(HtmlTextWriterAttribute.Id, "PaymentMethod");
 20             writer.AddStyleAttribute(HtmlTextWriterStyle.Width, "100%");
 21             writer.RenderBeginTag(HtmlTextWriterTag.Select);
 22
 23             writer.AddAttribute(HtmlTextWriterAttribute.Value, "0");
 24             writer.RenderBeginTag(HtmlTextWriterTag.Option);
 25             writer.Write("Master");
 26             writer.RenderEndTag();
 27
 28             writer.AddAttribute(HtmlTextWriterAttribute.Value, "1");
 29             writer.RenderBeginTag(HtmlTextWriterTag.Option);
 30             writer.Write("Visa");
 31             writer.RenderEndTag();
 32
 33             writer.RenderEndTag();
 34             writer.RenderEndTag();
 35             writer.RenderEndTag();
 36
 37             writer.RenderBeginTag(HtmlTextWriterTag.Tr);
 38             writer.RenderBeginTag(HtmlTextWriterTag.Td);
 39             writer.Write(CreditCardNoText);
 40             writer.RenderEndTag();
 41
 42             writer.RenderBeginTag(HtmlTextWriterTag.Td);
 43             writer.AddAttribute(HtmlTextWriterAttribute.Type, "text");
 44             writer.AddAttribute(HtmlTextWriterAttribute.Name, "CreditCardNo");
 45             writer.AddAttribute(HtmlTextWriterAttribute.Id, "CreditCardNo");
 46             writer.RenderBeginTag(HtmlTextWriterTag.Input);
 47             writer.RenderEndTag();
 48             writer.RenderEndTag();
 49             writer.RenderEndTag();
 50
 51             writer.RenderBeginTag(HtmlTextWriterTag.Tr);
 52             writer.RenderBeginTag(HtmlTextWriterTag.Td);
 53             writer.Write(CardholderNameText);
 54             writer.RenderEndTag();
 55
 56             writer.RenderBeginTag(HtmlTextWriterTag.Td);
 57             writer.AddAttribute(HtmlTextWriterAttribute.Type, "text");
 58             writer.AddAttribute(HtmlTextWriterAttribute.Name, 

"CardholderName");
 59             writer.AddAttribute(HtmlTextWriterAttribute.Id, "CardholderName");
 60             writer.RenderBeginTag(HtmlTextWriterTag.Input);
 61             writer.RenderEndTag();
 62             writer.RenderEndTag();
 63             writer.RenderEndTag();
 64
 65             writer.RenderBeginTag(HtmlTextWriterTag.Tr);
 66             writer.RenderBeginTag(HtmlTextWriterTag.Td);
 67             writer.Write(ExpirationDateText);
 68             writer.RenderEndTag();
 69
 70             writer.RenderBeginTag(HtmlTextWriterTag.Td);
 71             writer.AddAttribute(HtmlTextWriterAttribute.Name, "Month");
 72             writer.AddAttribute(HtmlTextWriterAttribute.Id, "Month");
 73             writer.RenderBeginTag(HtmlTextWriterTag.Select);
 74             for (int month = 1; month < 13; month++)
 75             {
 76                 writer.AddAttribute(HtmlTextWriterAttribute.Value, month.ToString());
 77                 writer.RenderBeginTag(HtmlTextWriterTag.Option);
 78                 writer.Write(month.ToString());
 79                 writer.RenderEndTag();
 80             }
 81
 82             writer.RenderEndTag();
 83
 84             writer.Write("&nbsp");
 85
 86             writer.AddAttribute(HtmlTextWriterAttribute.Name, "Year");
 87             writer.AddAttribute(HtmlTextWriterAttribute.Id, "Year");
 88             writer.RenderBeginTag(HtmlTextWriterTag.Select);
 89
 90             for (int year =2008; year < 2015; year++)
 91             {
 92                 writer.AddAttribute(HtmlTextWriterAttribute.Value, year.ToString());
 93                 writer.RenderBeginTag(HtmlTextWriterTag.Option);
 94                 writer.Write(year.ToString());
 95                 writer.RenderEndTag();
 96             }
 97
 98             writer.RenderEndTag();
 99
100             writer.RenderEndTag();
101             writer.RenderEndTag();
102
103
104             writer.RenderBeginTag(HtmlTextWriterTag.Tr);
105             writer.AddAttribute(HtmlTextWriterAttribute.Colspan, "2");
106             writer.AddAttribute(HtmlTextWriterAttribute.Align, "center");
107             writer.RenderBeginTag(HtmlTextWriterTag.Td);
108             writer.AddAttribute(HtmlTextWriterAttribute.Type, "submit");
109             writer.AddAttribute(HtmlTextWriterAttribute.Value, SubmitButtonText);
110             writer.RenderBeginTag(HtmlTextWriterTag.Input);
111             writer.RenderEndTag();
112             writer.RenderEndTag();
113             writer.RenderEndTag();
114
115             //table的結束標記
116             writer.RenderEndTag();
117
118
119
120
121         }