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FileUpload.HasFile 속성

정의

FileUpload 컨트롤에 파일이 들어 있는지 여부를 나타내는 값을 가져옵니다.

public:
 property bool HasFile { bool get(); };
[System.ComponentModel.Browsable(false)]
public bool HasFile { get; }
[<System.ComponentModel.Browsable(false)>]
member this.HasFile : bool
Public ReadOnly Property HasFile As Boolean

속성 값

Boolean

FileUpload에 파일이 들어 있으면 true이고, 그렇지 않으면 false입니다.

특성

예제

다음 예제에서는 만드는 방법을 보여 줍니다는 FileUpload 오류 검사를 수행 하는 컨트롤입니다. 파일을 저장 하기 전에 HasFile 메서드를 호출 하 여 업로드할 파일을 컨트롤에 포함 되어 있는지 확인 합니다. 또한는 File.Exists 메서드는 경로에 동일한 이름의 파일이 이미 발생 하는지 여부를 확인 합니다. 업로드할 파일의 이름 앞에 밑줄 문자를 접두사로 경우는 SaveAs 메서드가 호출 됩니다. 이 기존 파일 덮어쓰지 못하도록 방지 합니다.

<%@ 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.SaveAs Method Example</title>
<script runat="server">
        
    protected void  UploadButton_Click(object sender, EventArgs e)
    {
        // Before attempting to save the file, verify
        // that the FileUpload control contains a file.
        if (FileUpload1.HasFile) 
          // Call a helper method routine to save the file.
          SaveFile(FileUpload1.PostedFile);
        else
          // Notify the user that a file was not uploaded.
          UploadStatusLabel.Text = "You did not specify a file to upload.";
    }
            
      void SaveFile(HttpPostedFile file)
      {            
        // Specify the path to save the uploaded file to.
        string savePath = "c:\\temp\\uploads\\";
            
        // Get the name of the file to upload.
        string fileName = FileUpload1.FileName;
            
        // Create the path and file name to check for duplicates.
        string pathToCheck = savePath + fileName;
        
        // Create a temporary file name to use for checking duplicates.
        string tempfileName = "";
            
        // Check to see if a file already exists with the
        // same name as the file to upload.        
        if (System.IO.File.Exists(pathToCheck)) 
        {
          int counter = 2;
          while (System.IO.File.Exists(pathToCheck))
          {
            // if a file with this name already exists,
            // prefix the filename with a number.
            tempfileName = counter.ToString() + fileName;
            pathToCheck = savePath + tempfileName;
            counter ++;
          }
          
          fileName = tempfileName;
          
          // Notify the user that the file name was changed.
          UploadStatusLabel.Text = "A file with the same name already exists." + 
              "<br />Your file was saved as " + fileName;
        }
        else
        {
          // Notify the user that the file was saved successfully.
          UploadStatusLabel.Text = "Your file was uploaded successfully.";
        }

        // Append the name of the file to upload to the path.
        savePath += fileName;
            
        // Call the SaveAs method to save the uploaded
        // file to the specified directory.
        FileUpload1.SaveAs(savePath);
            
      }
        
</script>

</head>
<body>

    <h3>FileUpload.SaveAs Method 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>      
        
        <hr />
       
        <asp:Label id="UploadStatusLabel"
            runat="server">
        </asp:Label>   
         
    </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.SaveAs Method Example</title>
<script runat="server">
        
      Sub UploadButton_Click(ByVal sender As Object, ByVal e As System.EventArgs)
            
        ' Before attempting to save the file, verify
        ' that the FileUpload control contains a file.
        If (FileUpload1.HasFile) Then
          ' Call a helper method routine to save the file.
          SaveFile(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 SaveFile(ByVal file As HttpPostedFile)
            
        ' Specify the path to save the uploaded file to.
        Dim savePath As String = "c:\temp\uploads\"
            
        ' Get the name of the file to upload.
        Dim fileName As String = FileUpload1.FileName
            
        ' Create the path and file name to check for duplicates.
        Dim pathToCheck As String = savePath + fileName
        
        ' Create a temporary file name to use for checking duplicates.
        Dim tempfileName As String
            
        ' Check to see if a file already exists with the
        ' same name as the file to upload.        
        If (System.IO.File.Exists(pathToCheck)) Then
          Dim counter As Integer = 2
          While (System.IO.File.Exists(pathToCheck))
            ' If a file with this name already exists,
            ' prefix the filename with a number.
            tempfileName = counter.ToString() + fileName
            pathToCheck = savePath + tempfileName
            counter = counter + 1
          End While
          
          fileName = tempfileName
          
          ' Notify the user that the file name was changed.
          UploadStatusLabel.Text = "A file with the same name already exists." + "<br />" + _
                                   "Your file was saved as " + fileName
          
        Else
          
          ' Notify the user that the file was saved successfully.
          UploadStatusLabel.Text = "Your file was uploaded successfully."
          
        End If

        ' Append the name of the file to upload to the path.
        savePath += fileName
            
        ' Call the SaveAs method to save the uploaded
        ' file to the specified directory.
        FileUpload1.SaveAs(savePath)
            
      End Sub
        
  </script>

</head>
<body>

    <h3>FileUpload.SaveAs Method 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>      
        
        <hr />
       
        <asp:Label id="UploadStatusLabel"
            runat="server">
        </asp:Label>   
         
    </form>

</body>
</html>

설명

합니다 HasFile 속성이 나타내는 값을 가져옵니다 여부를 FileUpload 업로드할 파일을 포함 하는 컨트롤입니다. 업로드할 파일을 파일에 대 한 작업을 수행 하기 전에 있는지 확인 하려면이 속성을 사용 합니다. 예를 들어를 호출 하기 전에 SaveAs 디스크를 사용 하 여 파일을 저장 하는 방법을 HasFile 속성을 통해 파일이 있는지 확인 합니다. 하는 경우 HasFile 반환 true를 호출 합니다 SaveAs 메서드. 반환 하는 경우 false를 나타내는 사용자 컨트롤 파일 없습니다 메시지를 표시 합니다.

적용 대상

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