HtmlInputImage.Alt 属性

定义

获取或设置当图像不可用或尚未下载时浏览器显示的替换文本。

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

属性值

String

所指定图像的替换文本。 默认值为空字符串 ("")。

示例

下面的代码示例演示如何使用 Alt 属性指定要在图像不可用时显示的备用文本。

<%@ 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" >
   <script runat="server">

     protected void SubmitBtn_Click(object sender, ImageClickEventArgs e)
     {
       Message.InnerHtml = "The Submit button was clicked.";
     }

     protected void ClearBtn_Click(object sender, ImageClickEventArgs e)
     {
       Message.InnerHtml = "The Clear button was clicked.";
     }
     
</script>
 
   <head runat="server">
    <title>HtmlInputImage Example</title>
</head>
<body>
      <h3>HtmlInputImage Example</h3>

      <form id="form1" runat="server">

         <input type="image"
                alt="Submit button" 
                src="Submit.jpg" 
                onserverclick="SubmitBtn_Click" 
                runat="server"
                id="Image1" />

         <input type="image"
                alt="Clear button" 
                src="Clear.jpg" 
                onserverclick="ClearBtn_Click" 
                runat="server"
                id="Image2" />
 
         <h1> 
         
         <span id="Message" 
               runat="server">
         </span>

         </h1>

      </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">
<script runat="server">

  Sub SubmitBtn_Click(ByVal Source As Object, ByVal E As ImageClickEventArgs)
    Message.InnerHtml = "The Submit button was clicked."
  End Sub
 
  Sub ClearBtn_Click(ByVal Source As Object, ByVal E As ImageClickEventArgs)
    Message.InnerHtml = "The Clear button was clicked."
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
 
   <head runat="server">
    <title>HtmlInputImage Example</title>
</head>
<body>
      <h3>HtmlInputImage Example</h3>

      <form id="form1" runat="server">

         <input type="image"
                alt="Submit button" 
                src="Submit.jpg" 
                onserverclick="SubmitBtn_Click" 
                runat="server"
                id="Image1" />

         <input type="image"
                alt="Clear button" 
                src="Clear.jpg" 
                onserverclick="ClearBtn_Click" 
                runat="server" 
                id="Image2" />
 
         <h1> 
         
         <span id="Message" 
               runat="server">
         </span>

         </h1>

      </form>

   </body>

</html>

注解

使用此属性 Alt 指定要在指定图像不可用或尚未下载时显示的文本。 还可以使用此属性以编程方式确定指定的可选文本。

在支持工具提示功能的浏览器中,此文本也显示为控件的工具提示 HtmlInputImage

适用于

另请参阅