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PO
 

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  1. PO
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    <p>You can continue to use your empty string value and I would tend to prefer this to an assigned value, even though -1 is usually a good choice since it's highly unlikely that one of your filters would be using that as a value. I would clean up your query string though by calling something like the following function: </p> <pre><code>Private Function AppendFilter(ByVal filterName As String, ByVal filterVal As String, ByVal query As String) As String Dim res As String = query If filterVal.Length() &gt; 0 Then res = IIf(query.Length() &gt; 0, query &amp; "&amp;", query) &amp; filterName &amp; "=" &amp; filterVal End If Return res End Function </code></pre> <p>instead of this line from your code: <code>queryString = selectedAuthorString &amp; "&amp;" &amp; selectedSubjectString &amp; "&amp;" &amp; selectedTypeString</code></p> <p>Your resulting code would look like this: </p> <pre><code>Protected Sub buttonFilterGo_Click(ByVal sender As Object, ByVal e As EventArgs) Handles buttonFilterGo.Click Dim queryString As String = "" Const PATH As String = "~/paper/browse/?" queryString = AppendFilter("author", dropAuthorList.SelectedItem.Value, queryString) queryString = AppendFilter("subject", dropSubjectList.SelectedItem.Value, queryString) queryString = AppendFilter("type", dropPaperType.SelectedItem.Value, queryString) If queryString.Length() &lt;= 0 Then labelFilterFeedback.Text = "Apply some filters then press Go" Else Response.Redirect(PATH &amp; "?" &amp; queryString) labelFilterFeedback.Text = "" End If End Sub </code></pre> <p>And your query string won't contain filters that aren't applicable. </p>
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    1. POCreating multiple querystrings from drop down lists - Could be 1, 2 or 3 querystrings. How do I do it?
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    1. USnybbler
    1. USnybbler
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    1. COThis is great, but it only seems to work if all 3 filters are used. When I can get my brain in gear I will mess around with it and try to get it to work.Thanks!
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    2. CO@Robin That may be dependent on your handler appropriately handling the filters if they aren't defined, unless there's some error in my code I'm missing
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    3. CO@Robin: There was an issue with the AppendFilter function code. :S It's been fixed now.
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