FileUpload.PostedFile Eigenschaft
Definition
Wichtig
Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.
Ruft das zugrunde liegende HttpPostedFile-Objekt für eine Datei ab, die mit dem FileUpload-Steuerelement hochgeladen wird.
public:
property System::Web::HttpPostedFile ^ PostedFile { System::Web::HttpPostedFile ^ get(); };[System.ComponentModel.Browsable(false)]
public System.Web.HttpPostedFile PostedFile { get; }[<System.ComponentModel.Browsable(false)>]
member this.PostedFile : System.Web.HttpPostedFilePublic ReadOnly Property PostedFile As HttpPostedFileEigenschaftswert
Ein HttpPostedFile für eine mit FileUpload hochgeladene Datei.
- Attribute
Beispiele
Im folgenden Beispiel wird veranschaulicht, wie ein FileUpload Steuerelement erstellt wird. Wenn der Benutzer auf die Schaltfläche Hochladen Datei klickt, werden die Inhalte der Datei als Bytes in einem Textfeld auf der Seite angezeigt. In diesem Beispiel wird die Eigenschaft verwendet, um auf die PostedFile HttpPostedFile.ContentLength Eigenschaft zuzugreifen. Die ContentLength Eigenschaft wird verwendet, um die Länge der Datei zu bestimmen, bevor der Dateiinhalt in ein Bytearray kopiert wird.
<%@ 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">
protected void UploadButton_Click(object sender, EventArgs e)
{
// Specify the path on the server to
// save the uploaded file to.
String savePath = @"c:\temp\uploads\";
// Before attempting to perform operations
// on the file, verify that the FileUpload
// control contains a file.
if (FileUpload1.HasFile)
{
// Append the name of the file to upload to the path.
savePath += FileUpload1.FileName;
// Call the SaveAs method to save the
// uploaded file to the specified path.
// This example does not perform all
// the necessary error checking.
// If a file with the same name
// already exists in the specified path,
// the uploaded file overwrites it.
FileUpload1.SaveAs(savePath);
// Notify the user that the file was uploaded successfully.
UploadStatusLabel.Text = "Your file was uploaded successfully.";
// Call a helper routine to display the contents
// of the file to upload.
DisplayFileContents(FileUpload1.PostedFile);
}
else
{
// Notify the user that a file was not uploaded.
UploadStatusLabel.Text = "You did not specify a file to upload.";
}
}
void DisplayFileContents(HttpPostedFile file)
{
System.IO.Stream myStream;
Int32 fileLen;
StringBuilder displayString = new StringBuilder();
// Get the length of the file.
fileLen = FileUpload1.PostedFile.ContentLength;
// Display the length of the file in a label.
LengthLabel.Text = "The length of the file is " +
fileLen.ToString() + " bytes.";
// Create a byte array to hold the contents of the file.
Byte[] Input = new Byte[fileLen];
// Initialize the stream to read the uploaded file.
myStream = FileUpload1.FileContent;
// Read the file into the byte array.
myStream.Read(Input, 0, fileLen);
// Copy the byte array to a string.
for (int loop1 = 0; loop1 < fileLen; loop1++)
{
displayString.Append(Input[loop1].ToString());
}
// Display the contents of the file in a
// textbox on the page.
ContentsLabel.Text = "The contents of the file as bytes:";
TextBox ContentsTextBox = new TextBox();
ContentsTextBox.TextMode = TextBoxMode.MultiLine;
ContentsTextBox.Height = Unit.Pixel(300);
ContentsTextBox.Width = Unit.Pixel(400);
ContentsTextBox.Text = displayString.ToString();
// Add the textbox to the Controls collection
// of the Placeholder control.
PlaceHolder1.Controls.Add(ContentsTextBox);
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>FileUpload.FileContent Property Example</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h4>Select a file to upload:</h4>
<asp:FileUpload id="FileUpload1"
runat="server">
</asp:FileUpload>
<br /><br />
<asp:Button id="UploadButton"
Text="Upload file"
OnClick="UploadButton_Click"
runat="server">
</asp:Button>
<br /><br />
<asp:Label id="UploadStatusLabel"
runat="server">
</asp:Label>
<hr />
<asp:Label id="LengthLabel"
runat="server">
</asp:Label>
<br /><br />
<asp:Label id="ContentsLabel"
runat="server">
</asp:Label>
<br /><br />
<asp:PlaceHolder id="PlaceHolder1"
runat="server">
</asp:PlaceHolder>
</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">
Sub UploadButton_Click(ByVal sender As Object, ByVal e As System.EventArgs)
' Specify the path on the server to
' save the uploaded file to.
Dim savePath As String = "c:\temp\uploads\"
' Before attempting to perform operations
' on the file, verify that the FileUpload
' control contains a file.
If (FileUpload1.HasFile) Then
' Append the name of the file to upload to the path.
savePath += FileUpload1.FileName
' Call the SaveAs method to save the
' uploaded file to the specified path.
' This example does not perform all
' the necessary error checking.
' If a file with the same name
' already exists in the specified path,
' the uploaded file overwrites it.
FileUpload1.SaveAs(savePath)
' Notify the user that the file was uploaded successfully.
UploadStatusLabel.Text = "Your file was uploaded successfully."
' Call a helper routine to display the contents
' of the file to upload.
DisplayFileContents(FileUpload1.PostedFile)
Else
' Notify the user that a file was not uploaded.
UploadStatusLabel.Text = "You did not specify a file to upload."
End If
End Sub
Sub DisplayFileContents(ByVal file As HttpPostedFile)
Dim myStream As System.IO.Stream
Dim fileLen As Integer
Dim displayString As New StringBuilder()
Dim loop1 As Integer
' Get the length of the file.
fileLen = FileUpload1.PostedFile.ContentLength
' Display the length of the file in a label.
LengthLabel.Text = "The length of the file is " _
+ fileLen.ToString + " bytes."
' Create a byte array to hold the contents of the file.
Dim Input(fileLen) As Byte
' Initialize the stream to read the uploaded file.
myStream = FileUpload1.FileContent
' Read the file into the byte array.
myStream.Read(Input, 0, fileLen)
' Copy the byte array to a string.
For loop1 = 0 To fileLen - 1
displayString.Append(Input(loop1).ToString())
Next loop1
' Display the contents of the file in a
' textbox on the page.
ContentsLabel.Text = "The contents of the file as bytes:"
Dim ContentsTextBox As New TextBox
ContentsTextBox.TextMode = TextBoxMode.MultiLine
ContentsTextBox.Height = Unit.Pixel(300)
ContentsTextBox.Width = Unit.Pixel(400)
ContentsTextBox.Text = displayString.ToString()
' Add the textbox to the Controls collection
' of the Placeholder control.
PlaceHolder1.Controls.Add(ContentsTextBox)
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>FileUpload.FileContent Property Example</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h4>Select a file to upload:</h4>
<asp:FileUpload id="FileUpload1"
runat="server">
</asp:FileUpload>
<br /><br />
<asp:Button id="UploadButton"
Text="Upload file"
OnClick="UploadButton_Click"
runat="server">
</asp:Button>
<br /><br />
<asp:Label id="UploadStatusLabel"
runat="server">
</asp:Label>
<hr />
<asp:Label id="LengthLabel"
runat="server">
</asp:Label>
<br /><br />
<asp:Label id="ContentsLabel"
runat="server">
</asp:Label>
<br /><br />
<asp:PlaceHolder id="PlaceHolder1"
runat="server">
</asp:PlaceHolder>
</div>
</form>
</body>
</html>
Hinweise
Die PostedFile Eigenschaft ruft das zugrunde liegende HttpPostedFile Objekt für eine Datei ab, die mithilfe des FileUpload Steuerelements hochgeladen wird. Verwenden Sie diese Eigenschaft, um auf zusätzliche Eigenschaften in der hochgeladenen Datei zuzugreifen.
Sie können die ContentLength Eigenschaft verwenden, um die Länge der Datei abzurufen. Sie können die ContentType Eigenschaft verwenden, um den MIME-Inhaltstyp der Datei abzurufen. Darüber hinaus können Sie die Eigenschaft verwenden, um auf die Eigenschaft, die PostedFile FileName InputStream Eigenschaft und die SaveAs Methode zuzugreifen. Die gleiche Funktionalität wird jedoch von der Eigenschaft, der FileName FileContent Eigenschaft und der SaveAs Methode bereitgestellt.