FileUpload.FileContent Propiedad
Definición
Importante
Parte de la información hace referencia a la versión preliminar del producto, que puede haberse modificado sustancialmente antes de lanzar la versión definitiva. Microsoft no otorga ninguna garantía, explícita o implícita, con respecto a la información proporcionada aquí.
Obtiene un objeto Stream que señala a un archivo para cargarlo con el control FileUpload.
public:
property System::IO::Stream ^ FileContent { System::IO::Stream ^ get(); };[System.ComponentModel.Browsable(false)]
public System.IO.Stream FileContent { get; }[<System.ComponentModel.Browsable(false)>]
member this.FileContent : System.IO.StreamPublic ReadOnly Property FileContent As StreamValor de propiedad
Objeto Stream que señala a un archivo para cargarlo con el FileUpload.
- Atributos
Ejemplos
En el ejemplo siguiente se muestra cómo crear un FileUpload control . La FileContent propiedad se usa para leer el contenido del archivo en una matriz de bytes. Cuando el usuario hace clic en el botón Upload archivo, el contenido del archivo se muestra como bytes en un cuadro de texto de la página.
<%@ 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>
Comentarios
La FileContent propiedad obtiene un Stream objeto que apunta a un archivo que se va a cargar mediante el FileUpload control . Utilice la FileContent propiedad para tener acceso al contenido del archivo. Por ejemplo, puede usar el Stream objeto devuelto por esta propiedad para leer el contenido del archivo como bytes y almacenarlos en una matriz de bytes.