Net implements Multi-file upload code

. Net implements Multi-file upload code. It may be easy to upload a single file. However, many users do not upload multiple files. Other multi-file uploads are essentially different from single files, let's take a look at the following articles.

Protected bool upMorefile ()
{

// Traverse the File form Element
System. Web. HttpFileCollection files = System. Web. HttpContext. Current. Request. Files;
// Status information
System. Text. StringBuilder strMsg = new System. Text. StringBuilder ("successfully uploaded file information: Int fileCount;
Int filecount = files. Count;


Try
{
For (fileCount = 0; fileCount <files. Count; fileCount ++)
{
// Define the object for accessing the client to upload files
System. Web. HttpPostedFile postedFile = files [fileCount];
String FileType = postedFile. ContentType. ToString (); // obtain the file type to be uploaded and verify the file header.

String fileName, fileExtension;
// Get the uploaded file name
FileName = System. IO. Path. GetFileName (postedFile. FileName );
// Get the file extension
FileExtension = System. IO. Path. GetExtension (fileName );

// When the file to be uploaded is not empty, verify that the file name and size are consistent. If not, upload is not allowed.
If (FileType = "text/plain" & fileExtension. toLower () = ". txt ") | (FileType =" application/x-zip-compressed "& fileExtension. toLower () = ". zip ") | (FileType =" application/octet-stream "& fileExtension. toLower () = ". rar ") & postedFile. contentLength/1024 <= 1024)
{// Check whether the file header matches the file name to limit the File Upload type. Note: The File Upload types include TXT, ZIP, and RAR, and the file size can only be 1 MB.

If (fileName! = String. Empty)
{
FileName = RandomFileName () + fileExtension;

// Upload File Information
StrMsg. Append ("type of the uploaded file:" + postedFile. ContentType. ToString () + "<br> ");
StrMsg. Append ("client file address:" + postedFile. FileName + "<br> ");
StrMsg. Append ("file name to be uploaded:" + fileName + "<br> ");
StrMsg. Append ("the size of the uploaded file is:" + postedFile. ContentLength + "byte <br> ");
StrMsg. Append ("File Upload Extension:" + fileExtension + "<br> // Save to the specified folder
PostedFile. SaveAs (Server. MapPath ("public_file/" + UserName + "/") + fileName );
FileName = "";

}
}
Else
{
StrStatus. Text + = "no." + (fileCount + 1) + "non-conforming files <br/> ";

}

}

StrStatus. Text + = strMsg. ToString ();
Return true;
}
Catch (System. Exception error)
{
StrStatus. Text = error. Message;
Return false;

}
}

Protected void Upload_Click (object sender, EventArgs e)
{
StrStatus. Text = ""; // The prompt message is cleared.
UpMorefile (); // call the upload class

}

Public string RandomFileName ()
{// Class that returns a random number
String filename = "";
String r1 = "";
String r2 = "";
String r4 = "";
Random random = new Random ();
R1 = (char) random. Next (65, 90). ToString (); // uppercase letter
R2 = (char) random. Next (97,122). ToString (); // lowercase letter
R4 = random. Next (10000,999 999). ToString ();
Filename = DateTime. now. year. toString () + DateTime. now. month. toString () + DateTime. now. day. toString () + DateTime. now. hour. toString () + DateTime. now. minute. toString () + DateTime. now. second. toString () + DateTime. now. millisecond. toString () + r1 + r4 + r2 + r1 + r4 + r1;

Return filename;

}

The front-end code is as follows:

<Script language = "JavaScript">
Function addFileControl ()
{
Var str = '<INPUT type = "file" NAME = "File">'
Document. getElementById ('filecollect'). insertAdjacentHTML ("beforeEnd", str)
}
</Script>

<Asp: Panel ID = "PanelFileManage" runat = "server" Width = "100%">

<P id = "FileCollection"> <INPUT type = "file" name = "File"> & nbsp; </P>
<P align = "center" style = "color: Red">
Supported upload types: ZIP, RAR, TXT, and smaller than 1 MB </p>
<P align = "center"> <input onclick = "addFileControl ()" type = "button" value = "add (File)">
<Asp: button id = "Upload" Runat = "server" Text = "Upload" Width = "56px" OnClick = "Upload_Click"> </asp: button>
<Input style = "WIDTH: 56px; HEIGHT: 24px" onclick = "this. form. reset ()" type = "button" value = "reset">
</P>
<P align = "center"> <asp: label id = "strStatus" runat = "server" BorderColor = "White" BorderStyle = "None" Width = "500px"
Font-Size = "9pt" Font-Bold = "True" Font-Names = ""> </asp: label> </P>

</Asp: Panel>
You must add an enctype item to the form to use it. As follows:

<Form id = "form1" runat = "server" enctype = "multipart/form-data">