通过

HtmlForm.DefaultFocus 属性

  • 参考

定义

命名空间:
System.Web.UI.HtmlControls
程序集:
System.Web.dll

获取或设置窗体上的控件，该控件要在加载 HtmlForm 控件后显示为具有输入焦点的控件。

public:
 property System::String ^ DefaultFocus { System::String ^ get(); void set(System::String ^ value); };
public string DefaultFocus { get; set; }
member this.DefaultFocus : string with get, set
Public Property DefaultFocus As String

属性值

String

窗体上的控件的 ClientID，该控件要在加载 HtmlForm 后显示为具有输入焦点的控件。 默认值为空字符串 ("")。

示例

下面的代码示例演示了如何在窗体加载时将属性设置为 DefaultFocus 在窗体上显示为具有输入焦点的控件。 呈现时 Form1 ，请注意插入点位于其中 TextBox1，指示是 TextBox1 具有焦点的控件。

<%@ page language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">     
   
  void Page_Load(object sender, System.EventArgs e)
  {
    
    // Set the text of the two label controls.
    Label1.Text = "The DefaultButton property is set to "
                + Form1.DefaultButton.ToString() + "<br/>";
    Label2.Text = "The DefaultFocus property is set to "
                + Form1.DefaultFocus.ToString();
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >

<head>

    <title>HtmlForm DefaultButton and DefaultFocus Properties Example</title>

</head>

<body>

  <form id="Form1"
        defaultbutton="SubmitButton"
        defaultfocus="TextBox1"
        runat="server">
    
    <h3>HtmlForm DefaultButton and DefaultFocus Properties Example</h3>        
  
    TextBox1:
    <asp:textbox id="TextBox1"
                 autopostback="true" 
                 runat="server">
    </asp:textbox>
  
    <br />
  
    TextBox2:
    <asp:textbox id="TextBox2"
                 autopostback="true" 
                 runat="server">
    </asp:textbox>
  
    <br /><br />
  
    <asp:button id="SubmitButton"
                text="Submit" 
                runat="server">
    </asp:button>
  
    <asp:button id="CancelButton" 
                text="Cancel"
                runat="server">
    </asp:button>
  
    <hr />
  
    <asp:label id="Label1"
               runat="Server">
    </asp:label>
  
    <asp:label id="Label2"
               runat="Server">
    </asp:label>

  </form>

</body>

</html>

<%@ Page Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="Server">
       
  Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
    
    ' Set the text of the two label controls.
    Label1.Text = "The DefaultButton property is set to " _
                  & Form1.DefaultButton.ToString & "<br/>"
    Label2.Text = "The DefaultFocus property is set to " _
                  & Form1.DefaultFocus.ToString
  End Sub
     
 </script>

<html xmlns="http://www.w3.org/1999/xhtml" >

<head>

    <title>HtmlForm DefaultButton and DefaultFocus Properties Example</title>

</head>

<body>

  <form id="Form1"
        defaultbutton="SubmitButton"
        defaultfocus="TextBox1"
        runat="server">
    
    <h3>HtmlForm DefaultButton and DefaultFocus Properties Example</h3>        
  
    TextBox1:
    <asp:textbox id="TextBox1"
                 autopostback="true" 
                 runat="server">
    </asp:textbox>
  
    <br />
  
    TextBox2:
    <asp:textbox id="TextBox2"
                 autopostback="true" 
                 runat="server">
    </asp:textbox>
  
    <br /><br />
  
    <asp:button id="SubmitButton"
                text="Submit" 
                runat="server">
    </asp:button>
  
    <asp:button id="CancelButton" 
                text="Cancel"
                runat="server">
    </asp:button>
  
    <hr />
  
    <asp:label id="Label1"
               runat="Server">
    </asp:label>
  
    <asp:label id="Label2"
               runat="Server">
    </asp:label>

  </form>

</body>

</html>

注解

DefaultFocus使用属性访问窗体上的控件，在加载控件时显示为具有输入焦点的HtmlForm控件。 可以选择的控件会显示一个视觉提示，指示它们具有焦点。 例如， TextBox 具有焦点的控件显示，插入点位于其中。

还可以使用 Focus 或 SetFocus 方法设置具有焦点的控件。 这些方法优先于 DefaultFocus 属性。 如果调用上述任一方法来设置具有焦点的 DefaultFocus 控件，则忽略该属性的值。

适用于

另请参阅