ASP.NET using Button instead of FileUpload to upload files - asp.net

Question

I'm trying to upload a file with Button element using hidden FileUpload element with ASP.NET using this snippet:
protected void Page_Load(object sender, EventArgs e)
{
Button2.Attributes.Add("onclick", "document.getElementById('" + FileUpload1.ClientID + "').click();");
}
My Button has Id = "Button2", FileUpload Id = "FileUpload1". Clicking on the button Windows Explorer opens successfully to upload files but FileUpload.HasFile still returns false in further code (no file gets loaded even though explorer gets opened and file is selected).
What is the cause of this problem and how to fix it?

Answer 1

Well, I suppose you want to hide the the FileUpload Control and still be able to upload the files.
Follow the following steps to achieve the required:
Place a FileUpload Control with the class hidden. Like below:
<style>
.hidden{
display: none;
}
</style>
<asp:FileUpload runat="server" ID="FileUpload1" CssClass="hidden" />
Then place a Button that will be visible to client and will handle the Javascript events
<asp:Button runat="server" ID="Button1" Text="Upload File" OnClick="Button1_Clicked" />
Add the Javascript events to handle things
$(document).ready(function(){
// This event will help click the FileUpload control
$('#<%= Button1.ClientID %>').on('click', function(){
$('#<%= FileUpload1.ClientID %>').click();
return false; // important to return false, so it does not posts back yet.
});
$('#<%= FileUpload1.ClientID %>').on('change', function(){ // To see if the file selection was changed and the user has selected something
if($(this).val() == ''){
alert('No file selected');
return false;
}
if(confirm('Do you want to upload this file? ' + $(this).val())){
__doPostBack('<%= Button1.ClientID %>', ''); // this will postback to the server click event
}
});
});
Now, handle the uploaded file.
public void Button1_Clicked(object sender, EventArgs e)
{
// Handle your upload function
var hasFile = FileUpload1.HasFile;
}
PS: It was a rough Idea, the code is not tested so it might need some love.