c#上传文件并限制上传文件大小之方法

由 **eyke0519** 周三 1 二月 2012 - 0:39

代码:: 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。该控件将上载文件的大小限制为 5 MB。使用 PostedFile 属性来访问基础 ContentLength 属性并返回文件的大小。如果要上载的文件的大小小于 2 MB，则调用 SaveAs 方法将文件保存到服务器上的指定路径。除了检查应用程序代码中的最大文件大小设置之外，您还可以将 httpRuntime 元素的 maxRequestLength 属性设置为应用程序配置文件中所允许的最大大小。 < %@ 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>