共用方式為

CheckBox.AutoPostBack 屬性

  • 參考

定義

命名空間:
System.Web.UI.WebControls
組件:
System.Web.dll

取得或設定值，指出是否在按一下時自動回傳 CheckBox 狀態到伺服器。

public:
 virtual property bool AutoPostBack { bool get(); void set(bool value); };
public virtual bool AutoPostBack { get; set; }
[System.Web.UI.Themeable(false)]
public virtual bool AutoPostBack { get; set; }
member this.AutoPostBack : bool with get, set
[<System.Web.UI.Themeable(false)>]
member this.AutoPostBack : bool with get, set
Public Overridable Property AutoPostBack As Boolean

屬性值

Boolean

若要在按一下時，自動回傳 CheckBox 控制項的狀態至伺服器，則為 true，否則為 false。 預設為 false。

屬性
ThemeableAttribute

範例

下列範例示範如何使用 AutoPostBack 屬性，在單擊控件時，自動將控件的狀態 CheckBox 張貼到伺服器。

注意

下列程式代碼範例會使用單一檔案程式代碼模型，如果直接複製到程式代碼後置檔案，可能無法正常運作。 此程式代碼範例必須複製到具有.aspx擴展名的空白文本檔。 如需 Web Forms 程式代碼模型的詳細資訊，請參閱 ASP.NET Web Forms 頁面代碼模型。


<%@ Page Language="C#" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>CheckBox CheckedChanged Example</title>
<script runat="server">
 
      void Check_Clicked(Object sender, EventArgs e) 
      {

         // Calculate the subtotal and display the result in currency format.
         // Include tax if the check box is selected.
         Message.Text = CalculateTotal(checkbox1.Checked).ToString("c");

      }

      void Page_Load(Object sender, EventArgs e)
      {

         // Display the subtotal without tax when the page is first loaded.
         if(!IsPostBack)
         {

            // Calculate the subtotal and display the result in currency format.
            Message.Text = CalculateTotal(false).ToString("c");

         }

      }

      double CalculateTotal(bool Taxable)
      {

         // Calculate the subtotal for the example.
         double Result = 1.99 + 2.99 + 3.99;

         // Add tax, if applicable.
         if(Taxable)
         {
            Result += Result * 0.086;
         }

         return Result; 

      }
 
   </script>
 
</head>
 
<body>
 
   <form id="form1" runat="server">
 
      <h3>CheckBox CheckedChanged Example</h3>

      Select whether to include tax in the subtotal.

      <br /><br />

      <table border="1" cellpadding="5">

         <tr>

            <th colspan="2">

               Shopping cart

            </th>

         </tr>

         <tr>

            <td>

               Item 1

            </td>

            <td>

               $1.99

            </td>

         </tr>

         <tr>

            <td>

               Item 2

            </td>

            <td>

               $2.99

            </td>

         </tr>

         <tr>

            <td>

               Item 3

            </td>

            <td>

               $3.99

            </td>

         </tr>

         <tr>

            <td>

               <b>Subtotal</b>

            </td>

            <td>

               <asp:Label id="Message" runat="server"/>

            </td>

         </tr>

         <tr>

            <td colspan="2">

               <asp:CheckBox id="checkbox1" runat="server"
                    AutoPostBack="True"
                    Text="Include 8.6% sales tax"
                    TextAlign="Right"
                    OnCheckedChanged="Check_Clicked"/>

            </td>

         </tr>

      </table>
                   
   </form>
         
</body>

</html>


<%@ Page Language="VB" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>CheckBox CheckedChanged Example</title>
<script runat="server">
 
      Sub Check_Clicked(sender As Object, e As EventArgs) 

         ' Calculate the subtotal and display the result in currency format.
         ' Include tax if the check box is selected.
         Message.Text = CalculateTotal(checkbox1.Checked).ToString("c")

      End Sub

      Sub Page_Load(sender As Object, e As EventArgs)

         ' Display the subtotal without tax when the page is first loaded.
         If Not IsPostBack Then

            ' Calculate the subtotal and display the result in currency format.
            Message.Text = CalculateTotal(false).ToString("c")

         End If

      End Sub

      Function CalculateTotal(Taxable As Boolean) As Double 

         ' Calculate the subtotal for the example.
         Dim Result As Double = 1.99 + 2.99 + 3.99

         ' Add tax, if applicable.
         If(Taxable)

            Result += Result * 0.086
         
         End If

         Return Result 

      End Function
 
   </script>
 
</head>
 
<body>
 
   <form id="form1" runat="server">
 
      <h3>CheckBox CheckedChanged Example</h3>

      Select whether to include tax in the subtotal.

      <br /><br />

      <table border="1" cellpadding="5">

         <tr>

            <th colspan="2">

               Shopping cart

            </th>

         </tr>

         <tr>

            <td>

               Item 1

            </td>

            <td>

               $1.99

            </td>

         </tr>

         <tr>

            <td>

               Item 2

            </td>

            <td>

               $2.99

            </td>

         </tr>

         <tr>

            <td>

               Item 3

            </td>

            <td>

               $3.99

            </td>

         </tr>

         <tr>

            <td>

               <b>Subtotal</b>

            </td>

            <td>

               <asp:Label id="Message" runat="server"/>

            </td>

         </tr>

         <tr>

            <td colspan="2">

               <asp:CheckBox id="checkbox1" runat="server"
                    AutoPostBack="True"
                    Text="Include 8.6% sales tax"
                    TextAlign="Right"
                    OnCheckedChanged="Check_Clicked"/>

            </td>

         </tr>

      </table>
                   
   </form>
         
</body>

</html>

備註

使用這個屬性可指定單擊控件時，控件的狀態 CheckBox 是否回傳至伺服器。

注意

將此屬性設定為 true 會導致每次按兩下控制項時往返伺服器。

這個屬性無法由佈景主題或樣式表主題設定。 如需詳細資訊，請參閱 ThemeableAttribute 和 ASP.NET 主題和外觀。

適用於

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