HtmlInputFile Konstruktor

Definition

Namnområde:
System.Web.UI.HtmlControls
Sammansättning:
System.Web.dll

Initierar en ny instans av HtmlInputFile klassen.

public:
 HtmlInputFile();
public HtmlInputFile();
Public Sub New ()

Exempel

Följande kodexempel visar hur du skapar en ny instans av HtmlInputFile klassen. För att det här exemplet ska fungera korrekt måste du skapa en katalog som heter Temp på datorns enhet C.

<%@ 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">
<script runat="server">
  
  void Button1_Click(object sender, EventArgs e)
  {

    // Get the HtmlInputFile control from the Controls collection 
    // of the PlaceHolder control.
    HtmlInputFile file = (HtmlInputFile)Place.FindControl("File1");

    // Make sure a file was submitted.
    if (Text1.Value == "")
    {
      Span1.InnerHtml = "Error: You must enter a file name.";
      return;
    }

    // Save the file.
    if (file.PostedFile.ContentLength > 0)
    {
      try
      {
        
        file.PostedFile.SaveAs("c:\\temp\\" + Text1.Value);
        Span1.InnerHtml = "File uploaded successfully to " +
           "<b>c:\\temp\\" + Text1.Value + "</b> on the Web server.";
        
      }
      catch (Exception exc)
      {
        
        Span1.InnerHtml = "Error saving file <b>c:\\temp\\" +
           Text1.Value + "</b><br />" + exc.ToString() + ".";
        
      }
    }
  }

  void Page_Load(object sender, EventArgs e)
  {

    // Create a new HtmlInputFile control.
    HtmlInputFile file = new HtmlInputFile();
    file.ID = "File1";

    // Add the control to the Controls collection of the
    // PlaceHolder control.
    Place.Controls.Clear();
    Place.Controls.Add(file);

  }
 
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>HtmlInputFile Constructor Example</title>
  </head>

  <body>
 
   <h3>HtmlInputFile Constructor Example</h3>
 
   <form id="form1" enctype="multipart/form-data" 
         runat="server">
 
      Specify the file to upload:
      <asp:PlaceHolder id="Place" 
                       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>

   </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 Button1_Click(ByVal sender As Object, ByVal e As EventArgs)

    ' Get HtmlInputFile control from the Controls collection
    ' of the PlaceHolder control.
    Dim file As HtmlInputFile = _
       CType(Place.FindControl("File1"), HtmlInputFile)
 
    ' Make sure a file was submitted.
    If Text1.Value = "" Then
         
      Span1.InnerHtml = "Error: You must enter a file name."
      Return
          
    End If
 
    ' Save the file.
    If file.PostedFile.ContentLength > 0 Then

      Try
        
        file.PostedFile.SaveAs(("c:\temp\" & Text1.Value))
        Span1.InnerHtml = "File uploaded successfully to " & _
           "<b>c:\temp\" & Text1.Value & "</b> on the Web server."
        
      Catch exc As Exception
        
        Span1.InnerHtml = "Error saving file <b>c:\temp\" & _
           Text1.Value & "</b><br />" & exc.ToString() & "."
        
      End Try

    End If

  End Sub


  Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)

    ' Create a new HtmlInputFile control.
    Dim file As HtmlInputFile = New HtmlInputFile()
    file.ID = "File1"

    ' Add the control to the Controls collection of the
    ' PlaceHolder control.
    Place.Controls.Clear()
    Place.Controls.Add(file)

  End Sub
 
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>HtmlInputFile Constructor Example</title>
  </head>

<body>
 
   <h3>HtmlInputFile Constructor Example</h3>
 
   <form id="form1" enctype="multipart/form-data" 
         runat="server">
 
      Specify the file to upload:
      <asp:PlaceHolder id="Place"
                       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>
   </form>
 
</body>
</html>

Kommentarer

Använd den här konstruktorn för att skapa och initiera en ny instans av HtmlInputFile klassen.

I följande tabell visas det initiala egenskapsvärdet för en instans av HtmlInputFile.

Fastighet Initialt värde
Type Literalsträngen "file".

Gäller för