示例
第一个示例演示如何创建 FileUpload 控件，该控件将文件保存到代码中指定的路径。
<%@ 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)
{
// Get the name of the file to upload.
String fileName = FileUpload1.FileName;
// 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 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 of the name of the file
// was saved under.
UploadStatusLabel.Text = "Your file was saved as " + fileName;
}
else
{
// Notify the user that a file was not uploaded.
UploadStatusLabel.Text = "You did not specify a file to upload.";
}
}
</script>
<html >
<head runat="server">
<title>FileUpload 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>
<hr />
<asp:Label id="UploadStatusLabel"
runat="server">
</asp:Label>
</div>
</form>
</body>
</html>
第二个示例演示如何创建 FileUpload 控件，该控件将文件保存到文件系统中针对应用程序的指定目录。
<%@ 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)
{
// Save the uploaded file to an "Uploads" directory
// that already exists in the file system of the
// currently executing ASP.NET application.
// Creating an "Uploads" directory isolates uploaded
// files in a separate directory. This helps prevent
// users from overwriting existing application files by
// uploading files with names like "Web.config".
string saveDir = @"\Uploads\";
// Get the physical file system path for the currently
// executing application.
string appPath = Request.PhysicalApplicationPath;
// Before attempting to save the file, verify
// that the FileUpload control contains a file.
if (FileUpload1.HasFile)
{
string savePath = appPath + saveDir +
Server.HtmlEncode(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.";
}
else
{
// Notify the user that a file was not uploaded.
UploadStatusLabel.Text = "You did not specify a file to upload.";
}
}
</script>
<html >
<head runat="server">
<title>FileUpload Class Example</title>
</head>
<body>
<h3>FileUpload Class Example: Save To Application Directory</h3>
<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>
<hr />
<asp:Label id="UploadStatusLabel"
runat="server">
</asp:Label>
</div>
</form>
</body>
</html>
第三个示例演示如何创建 FileUpload 控件，该控件将文件保存到指定路径并限制可以上载的文件的大小。
<%@ 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 save the file, verify
// that the FileUpload control contains a file.
if (FileUpload1.HasFile)
{
// Get the size in bytes of the file to upload.
int fileSize = FileUpload1.PostedFile.ContentLength;
// Allow only files less than 2,100,000 bytes (approximately 2 MB) to be uploaded.
if (fileSize < 2100000)
{
// Append the name of the uploaded file to the path.
savePath += Server.HtmlEncode(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.";
}
else
{
// Notify the user why their file was not uploaded.
UploadStatusLabel.Text = "Your file was not uploaded because " +
"it exceeds the 2 MB size limit.";
}
}
else
{
// Notify the user that a file was not uploaded.
UploadStatusLabel.Text = "You did not specify a file to upload.";
}
}
</script>
<html >
<head runat="server">
<title>FileUpload Class 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>
<hr />
<asp:Label id="UploadStatusLabel"
runat="server">
</asp:Label>
</div>
</form>
</body>
</html>
第四个示例演示如何创建 FileUpload 控件，该控件将文件保存到指定路径并且只允许上载扩展名为 .doc 或 .xls 的文件。
<%@ 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 UploadBtn_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 save the file, verify
// that the FileUpload control contains a file.
if (FileUpload1.HasFile)
{
// Get the name of the file to upload.
string fileName = Server.HtmlEncode(FileUpload1.FileName);
// Get the extension of the uploaded file.
string extension = System.IO.Path.GetExtension(fileName);
// Allow only files with .doc or .xls extensions
// to be uploaded.
if ((extension == ".doc") | (extension == ".xls"))
{
// 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 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 their file was successfully uploaded.
UploadStatusLabel.Text = "Your file was uploaded successfully.";
}
else
{
// Notify the user why their file was not uploaded.
UploadStatusLabel.Text = "Your file was not uploaded because " +
"it does not have a .doc or .xls extension.";
}
}
}
</script>
<html >
<head runat="server">
<title>FileUpload Class 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="UploadBtn"
Text="Upload file"
OnClick="UploadBtn_Click"
runat="server">
</asp:Button>
<hr />
<asp:Label id="UploadStatusLabel"
runat="server">
</asp:Label>
</div>
</form>
</body>
</html>