通用型(common)的伺服器控制項，指的是 Label 、 TextBox 、 Button 、 CheckBox 、 RadioButton 這類較基本功能的控制項。
The Label Control
這個控制項比較沒什麼好講的，值得一提的是，若由後置程式碼填資料到 Label 控制項，必項注意安全性問題。 因為它可能引發 XSS 資安弱點。 若要避免這個問題，可以使用 HttpUtility.HtmlEncode 或 Server.HtmlEncode 方法，在資料填入前先行編碼。
string script = @"<script>alert('test1');</script>";
Label1.Text = HttpUtility.HtmlEncode(script);
//碥碼後的文字： &lt;script&gt;alert(&#39;test&#39;);&lt;/script&gt;
The TextBox Control
- TextMode ：設定的行為模式 (SingleLine / MultiLine / Password)。
- MaxLength ：設定文字方塊中所允許的字元數目上限。
- Wrap ：設定多行文字方塊中的文字內容是否換行。(default=true)。
The Button Control
A Button control can also be used as a command button, which is one of a set of buttons that work together as a group, such as a toolbar. You define a button as a command button by assigning a value to its CommandName property. When a user clicks one of the command buttons, its Command event is called on the server. This event is passed an instance of CommandEventArgs as a parameter.
<asp:Button ID="Button4" runat="server" Text="<<" CommandName="previous" oncommand="Play_Command" />
<asp:Button ID="Button5" runat="server" Text="●" CommandName="play" oncommand="Play_Command" />
<asp:Button ID="Button6" runat="server" Text=">>" CommandName="next" oncommand="Play_Command" />
protected void Play_Command(object sender, CommandEventArgs e)
{
switch (e.CommandName)
{
case "previous":
myMessage.Show(this, "Previous");
break;
case "play":
myMessage.Show(this, "Play");
break;
case "next":
myMessage.Show(this, "Next");
break;
}
}
The CheckBox Control
The CheckBox control gives the user the ability to select between true and false.
- Text ：
- TextAlign ：
- Checked ：
- AutoPostBack ：是否自動回傳。
- CheckedChanged ：Event 發生於 Checked 屬性的值變更時。
若 AutoPostBack = false ，這個 CheckedChanged 事件就不會引發 PostBack ； 但是若其它控制項發生 PostBack 事件時， CheckChanged 事件還是會被執行。 ```xml
# The RadioButton Control
The [RadioButton](http://msdn.microsoft.com/zh-tw/library/system.web.ui.webcontrols.radiobutton.aspx) control gives the user the ability to select between mutually exclusive [RadioButton](http://msdn.microsoft.com/zh-tw/library/system.web.ui.webcontrols.radiobutton.aspx) controls in a group. This is useful when you are asking a user to select a single item from a group of items. To group multiple [RadioButton](http://msdn.microsoft.com/zh-tw/library/system.web.ui.webcontrols.radiobutton.aspx) controls together, specify the same [GroupName](http://msdn.microsoft.com/zh-tw/library/system.web.ui.webcontrols.radiobutton.groupname.aspx) for each [RadioButton](http://msdn.microsoft.com/zh-tw/library/system.web.ui.webcontrols.radiobutton.aspx) control in the group.
```xml
<asp:RadioButton ID="RadioButton1" runat="server" GroupName="Fruit" Text="Apple" /><br />
<asp:RadioButton ID="RadioButton2" runat="server" GroupName="Fruit" Text="Melon" /><br />
<asp:RadioButton ID="RadioButton3" runat="server" GroupName="Fruit"
Text="Tangerine"
TextAlign="Right"
Checked="true"
AutoPostBack="true"
oncheckedchanged="RadioButton1_CheckedChanged"
/>