image upload to file system

Question

how can i upload an image to the file systm?

score 1 · Answer 1 · edited May 23 '17 at 12:26

Use the FileUpload control.

For example (modified from the linked MSDN article), if you just want a simple form which uploads a file to a path on the server, you can start with something like this:

<%@ Page Language="C#" %>

<script runat="server">
    protected void UploadFileAction_Click(object sender, EventArgs e)
    {
        var fileStoragePath = Server.MapPath("~/Uploads");

        if (fileUploader.HasFile)
        {
            fileUploader.SaveAs(Path.Combine(fileStoragePath, fileUploader.FileName));
            outputLabel.Text = string.Format(
                "File Name: {0}<br />File Size: {1}kb<br />Content Type: {2}",
                fileUploader.PostedFile.FileName,
                fileUploader.PostedFile.ContentLength,
                fileUploader.PostedFile.ContentType
            );
        }
        else
            outputLabel.Text = "You have not specified a file.";
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Upload A File</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:FileUpload ID="fileUploader" runat="server" /><br />
        <br />
        <asp:Button ID="uploadFileAction" runat="server" OnClick="UploadFileAction_Click" Text="Upload File" />&nbsp;<br />
        <br />
        <asp:Label ID="outputLabel" runat="server"></asp:Label></div>
    </form>
</body>
</html>

The FileUpload control ends up rendering to a simple <input type="file" /> (but with more attributes set, of course) on the client, as part of the overall ASP.NET form element management like any other server-side form control.

In your question, you specifically mention uploading an "image." While this code may get you there, you might also be implicitly asking a second question which is, "How can I ensure that the uploaded file is an image?" If so, you have a few options outlined very well in the answers to this question as well as this one (which refers to more answers on other questions, it's a popular topic). As always, server-side validation is necessary even though client-side validation is still recommended for a good UX. Never implicitly trust the client-side validation, always validate user input on the server as well.

While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. — Rob, Nov 17 '12 at 10:58
@Rob: Thanks for bringing that to my attention. This was one of my older hit-and-run answers that I never went back and updated. Fixed. — David, Nov 17 '12 at 12:00

Predator · Answer 2 · 2011-03-29T00:33:30.720

Here is the code sample:

Your html:

<input type="file" name="Pic_0001">

NOTE: the html input control must be located within the form

Now your asp .net code:

    'this is your file name at html page
    Dim HtmlFilename As String = "Pic_0001"

    'the place to manipulate all uploaded files
    Dim collection As System.Web.HttpFileCollection
    collection = Page.Request.Files

    'for example, you have selected a picture file named hotdog.jpg in browser
    'this variable will manipulate your hotdog.jpg file
    Dim UploadedFile As System.Web.HttpPostedFile

    'retrieve the reference to your file
    UploadedFile = collection.Item(HtmlFilename)

    'this is the location to save your uploaded file
    Dim WhereToSave As String = "c:\test folder\hotdog.jpg"

    'this is your folder that will contain the uploaded file
    Dim Folderpath As String = System.IO.Path.GetDirectoryName(WhereToSave)

    'now do checking if the folder exists, if not create the folder
    'NOTE: this step is needed to prevent folder not exists error
    If System.IO.Directory.Exists(Folderpath) = False Then
        System.IO.Directory.CreateDirectory(Folderpath)
    End If

    'now actually save your file to the server
    UploadedFile.SaveAs(WhereToSave)

image upload to file system

2 Answers2