FileUpload.PostedFile Propiedad

Referencia

Definición

Espacio de nombres:: System.Web.UI.WebControls

Ensamblado:: System.Web.dll

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 el objeto HttpPostedFile subyacente para un archivo que se carga con el control FileUpload.

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.HttpPostedFile

Public ReadOnly Property PostedFile As HttpPostedFile

Valor de propiedad

HttpPostedFile

HttpPostedFile para un archivo cargado mediante el FileUpload.

Atributos: BrowsableAttribute

Ejemplos

En el ejemplo siguiente se muestra cómo crear un FileUpload control . 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. En este ejemplo se usa la PostedFile propiedad para tener acceso a la HttpPostedFile.ContentLength propiedad . La ContentLength propiedad se usa para determinar la longitud del archivo antes de copiar el contenido del archivo en una matriz de bytes.

<%@ 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 PostedFile propiedad obtiene el objeto subyacente HttpPostedFile de un archivo que se carga mediante el FileUpload control . Use esta propiedad para tener acceso a propiedades adicionales en el archivo cargado.

Puede usar la ContentLength propiedad para obtener la longitud del archivo. Puede usar la ContentType propiedad para obtener el tipo de contenido MIME del archivo. Además, puede usar la PostedFile propiedad para tener acceso a la FileName propiedad, la InputStream propiedad y el SaveAs método . Sin embargo, la propiedad proporciona la FileName misma funcionalidad, la FileContent propiedad y el SaveAs método .

Se aplica a

Consulte también

HttpPostedFile

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