I am developing a scanning application and I need to do some validation and db updates and then scan the document.
I have tried various approaches based on searching for answers and not able to locate anything.
<asp:ScriptManager ID="script1" runat="server" EnablePageMethods="true"></asp:ScriptManager>
<asp:UpdatePanel ID="panel1" runat="server">
<ContentTemplate>
<tr><td><asp:Button ID="btnScan" runat="server" Text="Scan" OnClick="Scan" OnClientClick="return AcquireImage()" /><p></td></tr>
</ContentTemplate>
</asp:UpdatePanel>
</table>
</td>
<td>
<table width=100% >
<tr><td>
<div id="dwtcontrolContainer" > </div>
</td></tr>
</table>
<script type="text/javascript">
function AcquireImage() {
var DWObject = Dynamsoft.WebTwainEnv.GetWebTwain('dwtcontrolContainer');
DWObject.IfDisableSourceAfterAcquire = 'true';
DWObject.SelectSource();
DWObject.OpenSource();
DWObject.AcquireImage();
// var isPostBack = <%=Convert.ToString(Page.IsPostBack).ToLower()%>;
// alert(isPostBack);
return true;
}
Have even tried removing the OnClientClick and executing the javascript through the onClick event. It enters the Onclick but won't execute the javascript
if (enddate.Text == "")
{
ScriptManager.RegisterClientScriptBlock(this, this.GetType(), "key", "alert('Please enter a Transaction date before scanning');", true);
return;
}
//ScriptManager.RegisterStartupScript(this, this.GetType(), "myScript", "AcquireImage()", false);
Page.ClientScript.RegisterStartupScript(this.GetType(), "CallMAnotherFunction", "javascript:AcquireImage();", true);
Any help would be greatly appreciated.
OnClientClick event runs on client-side and OnClick event runs on server-side. OnClientClick triggers first, so it's impossible to execute the OnClick event before OnClientClick .
According to your requirement, you need to run server-side code first, and then run a client-side callback. Here is my solution.
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="head1" runat="server">
<title>Button.OnClientClick Example</title>
<script type="text/javascript" src="http://tst.dynamsoft.com/libs/dwt/14.0/dynamsoft.webtwain.min.js"> </script>
</head>
<body>
<script runat="server">
void Button1_Click(object sender, EventArgs e)
{
string script = @"
var DWObject = Dynamsoft.WebTwainEnv.GetWebTwain('dwtcontrolContainer');
DWObject.IfDisableSourceAfterAcquire = true;
var bSelected = DWObject.SelectSource();
if(bSelected) {
var OnAcquireImageSuccess, OnAcquireImageFailure;
OnAcquireImageSuccess = OnAcquireImageFailure = function () {
DWObject.CloseSource();
};
};
DWObject.OpenSource();
DWObject.AcquireImage(OnAcquireImageSuccess, OnAcquireImageFailure);
";
bool isTrue = true;
if (isTrue)
{
ScriptManager.RegisterClientScriptBlock(this, GetType(), "key", script, true);
}
}
</script>
<form id="form1" runat="server">
<h3>Dynamsoft Dynamic Web TWAIN Demo</h3>
<p></p>
<div id="dwtcontrolContainer"></div>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Button ID="Button1" runat="server" CausesValidation="False" OnClick="Button1_Click" Text="Scan Documents" UseSubmitBehavior="False" />
</ContentTemplate>
</asp:UpdatePanel>
</form>
</body>
</html>
Note: the ScriptManager and UpdatePanel ( AJAX Extension ) are required in order to make Dynamic Web TWAIN code work.
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