ASP.NET多个文件上传

Question

I'm building a website (umbraco based) where the users are able to upload multiple images to their posts. What I have so far is:

<asp:TextBox MaxLength="1" Width="29px" runat="server" ID="txtImageAmount" />&nbsp;
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
    <ContentTemplate>
       <asp:Button ID="btnSubmitImageAmount" runat="server" Text="Vis upload felter" 
            onclick="btnSubmitImageAmount_Click" />

       <asp:Label Visible="false" ID="lblImageAmountError" ForeColor="Red" runat="server" Text="Maks 3 billeder"></asp:Label>  
       <asp:Panel ID="pnlUploadControls" Visible="false" runat="server"></asp:Panel>
    </ContentTemplate>
</asp:UpdatePanel>  

So the user is able to choose the amount of fileupload boxes (max 3 though) on the site.

My C# looks like this:

protected void btnSubmitImageAmount_Click(object sender, EventArgs e)
{
    int amountOfControls = Convert.ToInt32(txtImageAmount.Text);
    if (amountOfControls <= 3)
    {
        for(int i = 0; i < amountOfControls; i++)
        {
            FileUpload fUl = new FileUpload();
            fUl.ID = i.ToString();
            fUl.Width = 300;
            Label lblLinebreak = new Label();
            lblLinebreak.Text = "<br />";
            pnlUploadControls.Controls.Add(fUl);
            pnlUploadControls.Controls.Add(lblLinebreak);
            pnlUploadControls.Visible = true;
        }
    }
    else
    {
        lblImageAmountError.Visible = true;
    }
}

So basically I'm adding a new FileUpload control to the Panel depending on how many the user wants.

Now, in my Save button I have the following code:

List<Media> images = new List<Media>();

    foreach (FileUpload fUl in pnlUploadControls.Controls)
    {
        Media m = UmbracoSave(fUl);
        if (m != null)
        {
            images.Add(m);
        }       
    }

    if (images.Count > 0)
    {
        RelationType ad2media = RelationType.GetByAlias("ad2media");
        foreach (Media img in images)
        {
            Relation.MakeNew(adDoc.Id, img.Id, ad2media, adDoc.Text + " is related to " + img.Text);
        }
    }

I have tried to check if the amount of controls in the panel is equal to 0 and it seems it is.. The weird thing is, if I check if the Media item returned from the UmbracoSave method is null, it isn't.

Also, it says that the List (images) count is 0..

Can anyone shed some light on this? :-)

Any help is greatly appreciated!

All the best,

Bo

Answer 1

You can't put a standard FileUpload control in an UpdatePanel. It just doesn't work. Look at an AJAX compatible file upload component.