Why does asp.net fileupload control corrupt files?

I am using FileUpload control to upload multiple files and it does successfully but problem is that when I download files after uploading then it becomes corrupt i.e. .pdf, .docx etc. Upon inspection I found that the problem is with upload control because I checked file in server directory after uploading and tried opening it but files throws error i.e. file is corrupt.

I checked every the uploaded file in server directory, it doesn't work there too, so the problem is that it uploads incorrectly 

protected void UploadIncomingLetterMaterial(int CaseLetterID)
{
    if (FileUpload1.HasFiles)
    {

        foreach (HttpPostedFile uploadedfiles in FileUpload1.PostedFiles)
        {
            string fileName = Path.GetFileName(uploadedfiles.FileName);
            FileUpload1.PostedFile.SaveAs(Server.MapPath("~/SiteImages/") + fileName);

            mngUploadedMaterialIncomingLetters.InsertUploadedMaterialIncomingLetters(fileName, "", CaseLetterID);
        }

UPDATE:

The problem is that when i upload multiple files then it makes the size of all files same. Same to the size of first file in loop.

Jon Skeet
people
quotationmark

It looks like this is the problem:

FileUpload1.PostedFile.SaveAs(Server.MapPath("~/SiteImages/") + fileName);

That's saving the first file multiple times - you're trying to save the file you're currently referring to as uploadedfiles (which should be singular). It looks like you should have:

foreach (HttpPostedFile uploadedFile in FileUpload1.PostedFiles)
{
    string fileName = Path.GetFileName(uploadedFile.FileName);
    uploadedFile.SaveAs(Server.MapPath("~/SiteImages/") + fileName);
    mngUploadedMaterialIncomingLetters.InsertUploadedMaterialIncomingLetters(fileName, "", CaseLetterID);
}

people

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