通用 Server Controls

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： &amp;lt;script&amp;gt;alert(&amp;#39;test&amp;#39;);&amp;lt;/script&amp;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。

<asp:CheckBox ID="CheckBox1" runat="server"
        Text="是/否" 
        TextAlign="Left" 
        Checked="true"
        AutoPostBack="false" 
        onCheckedChanged="CheckBox1_CheckedChanged" 
    />

The RadioButton Control

The RadioButton control gives the user the ability to select between mutually exclusive RadioButton 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 controls together, specify the same GroupName for each RadioButton control in the group.

<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"
    />

ListBox

DropDownList

CheckBoxList

BulletedList

RadioButtonList

AdRotator