HtmlInputFile.Accept 属性
定义
重要
一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。 对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。
获取或设置用逗号分隔的 MIME 编码列表，该列表用于约束用户可以选择的文件类型。
public:
property System::String ^ Accept { System::String ^ get(); void set(System::String ^ value); };public string Accept { get; set; }member this.Accept : string with get, setPublic Property Accept As String属性值
用逗号分隔的 MIME 编码列表。
示例
下面的代码示例演示如何使用 Accept 属性来限制用户选择图像文件以外的任何文件。 若要使此示例正常工作，需要在计算机的驱动器 C 上创建一个调用 Temp 的目录。由于对属性的支持 Accept 依赖于浏览器，因此将执行服务器端检查以确保仅上传图像。 如果上传的文件无法作为 Image 类型读取，则会引发异常。
<%@ 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 Button1_Click(object Source, EventArgs e)
{
// Check to see if a file was selected.
if (Text1.Value == "")
{
Span1.InnerHtml = "Error: You must enter a file name.";
return;
}
// Save the file.
if (File1.PostedFile.ContentLength > 0)
{
try
{
try
{
using (System.Drawing.Image input =
System.Drawing.Image.FromStream(File1.PostedFile.InputStream))
{
File1.PostedFile.SaveAs("c:\\temp\\" +
Server.HtmlEncode(Text1.Value));
Span1.InnerHtml = "File uploaded successfully to <b>c:\\temp\\" +
Server.HtmlEncode(Text1.Value) +
"</b> on the Web server.";
}
}
catch
{
throw new Exception("Not a valid image file.");
}
}
catch (Exception exc)
{
Span1.InnerHtml = "Error saving file <b>c:\\temp\\" +
Server.HtmlEncode(Text1.Value) +
"</b>. " + exc.Message;
}
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>HmtlInputFile Example</title>
</head>
<body>
<form id="Form1" enctype="multipart/form-data"
runat="server">
<div>
Select File to Upload:
<input id="File1"
type="file"
accept="image/*"
runat="server"/>
<p>
Save as file name (no path):
<input id="Text1"
type="text"
runat="server"/>
</p>
<p>
<span id="Span1"
style="font: 8pt verdana;"
runat="server" />
</p>
<p>
<input type="button"
id="Button1"
value="Upload"
onserverclick="Button1_Click"
runat="server" />
</p>
</div>
</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">
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs)
' Check to see if a file was selected.
If (Text1.Value = "") Then
Span1.InnerHtml = "Error: You must enter a file name."
Return
End If
' Save the file
If (File1.PostedFile.ContentLength > 0) Then
Try
Try
Using input As System.Drawing.Image = _
System.Drawing.Image.FromStream(File1.PostedFile.InputStream)
File1.PostedFile.SaveAs("c:\\temp\\" & _
Server.HtmlEncode(Text1.Value))
Span1.InnerHtml = "File uploaded successfully to <b>c:\\temp\\" & _
Server.HtmlEncode(Text1.Value) & _
"</b> on the Web server."
End Using
Catch
Throw New Exception("Not a valid image file.")
End Try
Catch exc As Exception
Span1.InnerHtml = "Error saving file <b>c:\\temp\\" & _
Server.HtmlEncode(Text1.Value) & _
"</b>. " & exc.Message
End Try
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>HtmlInputFile Example</title>
</head>
<body>
<form id="form1" runat="server">
<div>
Select File to Upload:
<input id="File1"
type="file"
accept="image/jpeg"
runat="server"/>
<p>
Save as file name (no path):
<input id="Text1"
type="text"
runat="server"/>
</p>
<p>
<span id="Span1"
style="font: 8pt verdana;"
runat="server" />
</p>
<p>
<input type="button"
id="Button1"
value="Upload"
onserverclick="Button1_Click"
runat="server" />
</p>
</div>
</form>
</body>
</html>
注解
使用此属性可指定可上传到服务器的文件类型。 例如，若要将所选内容限制为图像，请将此属性设置为“image/*”。
备注
对此属性的支持依赖于浏览器。 检查浏览器以确定它是否支持此属性。 建议使用服务器端代码来确保文件为预期类型。