FileUpload.FileBytes FileUpload.FileBytes FileUpload.FileBytes FileUpload.FileBytes Property

定義

FileUpload コントロールを使用して、指定したファイルに格納されているバイトの配列を取得します。Gets an array of the bytes in a file that is specified by using a FileUpload control.

public:
 property cli::array <System::Byte> ^ FileBytes { cli::array <System::Byte> ^ get(); };
[System.ComponentModel.Bindable(true)]
[System.ComponentModel.Browsable(false)]
public byte[] FileBytes { get; }
member this.FileBytes : byte[]
Public ReadOnly Property FileBytes As Byte()

プロパティ値

Byte[]

指定したファイルの内容を格納する Byte 配列。A Byte array that contains the contents of the specified file.

例外

ファイルの一部が読み取られていません。The entire file was not read.

次の例では、作成する方法、FileUploadコントロール。The following example demonstrates how to create a FileUpload control. ユーザーがクリックすると、ファイルのアップロードボタン、ファイルの内容は、ページのテキスト ボックス内のバイトとして表示されます。When the user clicks the Upload file button, the contents of the file are displayed as bytes in a text box on the page. この例では、FileBytesファイル全体をアップロードするプロパティ。This example uses the FileBytes property to upload the entire file.

<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>FileUpload.FileContent Property Example</title>
<script runat="server">
        
        private void DisplayFileContents(HttpPostedFile file) 
        {            
            int fileLen;
            string displayString = "";
            
            // 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 - 1];
            input = FileUpload1.FileBytes;
            
            // Copy the byte array to a string.
            for (int loop1 = 0; loop1 < fileLen; loop1++) {
                displayString = displayString + 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;
            
            // Add the textbox to the Controls collection
            // of the Placeholder control.
            PlaceHolder1.Controls.Add(ContentsTextBox);

        }

    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.";
            }
    }
</script>

</head>
<body>

    <h3>FileUpload.FileContent Property Example</h3>

    <form id="Form1" runat="server">
   
        <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>         
         
    </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">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>FileUpload.FileContent Property Example</title>
<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 fileLen As Integer
            Dim displayString As String = ""
            
            ' 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 - 1) As Byte
            Input = FileUpload1.FileBytes
            
            ' Copy the byte array to a string.
            For loop1 As Integer = 0 To fileLen - 1
                displayString = displayString & 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
            
            ' Add the textbox to the Controls collection
            ' of the Placeholder control.
            PlaceHolder1.Controls.Add(ContentsTextBox)

        End Sub

    </script>

</head>
<body>

    <h3>FileUpload.FileContent Property Example</h3>

    <form id="Form1" runat="server">
   
        <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>         
         
    </form>

</body>
</html>

注釈

FileUploadコントロールで、ファイルが自動的にクライアントから読み取りできません。The FileUpload control does not automatically read the file from the client. コントロールまたはユーザーが、指定したファイルを送信できるようにするためのメカニズムを明示的に指定する必要があります。You must explicitly provide a control or mechanism to allow the user to submit the specified file. たとえば、ファイルをアップロードして、ユーザーがクリックできるボタンを行うことができます。For example, you can provide a button that the user can click to upload the file. 指定したファイルを保存するために作成コードを呼び出すことが、FileBytesプロパティで、ファイルの内容を返します。The code that you write to save the specified file could call the FileBytes property, which returns the contents of the file.

呼び出しの前に、FileBytesプロパティを使用する必要がある、HasFileことを確認するプロパティ、FileUploadコントロールにアップロードするファイルが含まれています。Before calling the FileBytes property, you should use the HasFile property to verify that the FileUpload control contains a file to upload. 場合、HasFile返しますtrueを呼び出し、FileBytesプロパティ。If the HasFile returns true, call the FileBytes property. 返された場合falseコントロールにファイルが含まれていないユーザーを示すメッセージを表示します。If it returns false, display a message to the user indicating that the control does not contain a file. 存在しないファイルを保存しようとスロー ファイルが存在することを確認するエラー処理コードを指定しない場合、HttpException例外。If you do not provide error-handling code to verify that a file exists, an attempt to save a nonexistent file throws an HttpException exception.

適用対象

こちらもご覧ください