SharePoint 2013:Configure RDLC report with Report Viewer

Here are the steps to configure the SharePoint for report:

        First find the following line in AppSettings in your web.config file and comment it out as shown below:

<!--<add key="ReportViewerMessages" value="Microsoft.SharePoint.Portal.Analytics.UI.ReportViewerMessages, Microsoft.SharePoint.Portal, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" />-->

     Enable session at page level by setting the enableSessionState to true of <page…..> tag inside system.web.

<pages enableSessionState="true" enableViewState="true" enableViewStateMac="true" validateRequest="false" ……………………=""

       SharePoint disable the default session module inside the <system. Webserver>\modules tag. To enable the module comment out the following line inside <system. Webserver>\modules as shown below:

<!--<remove name="Session" />-->

Now if you try to put a report viewer control you will find a message like below:

If you find the above error then follow the steps 4, 5 and6:

      Add the following tag inside system.web\httphandlers section

<system.web>

    <httpHandlers>

      <add verb="*" path="Reserved.ReportViewerWebControl.axd" type="Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=11.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91" />

    </httpHandlers>

<customErrors mode="Off" />

     Add the following line in the system. Webserver\handlers

<add name="ReportViewerWebControlHandler" preCondition="integratedMode" verb="*" path="Reserved.ReportViewerWebControl.axd" type="Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=11.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91" />

    Comment out the following line in the system. Webserver\httphandlers (If Exists)

      <!--<add name="ReportViewerWebControl" verb="*" path="Reserved.ReportViewerWebControl.axd" type="Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />-->

And finally it worked………..

     I got an error while viewing the Report in sharepoint Page
                   

Issue: Report execution in the current AppDomain requires Code Access Security policy, which is off by default in .NET 4.0 and later. Enable legacy CAS policy or execute the report in the sandbox AppDomain.

To resolve this issue –

Add the following line to the web.config

...

<trust level="Full" legacyCasModel="true" />

...

</system.web>

No more post back after file download in sharepoint

I had this issue with sharepoint. I have a button on the page that sends a file and after clicking the button, the rest of the form was unresponsive. Turns out it is a sharepoint thing that sets the variable _spFormOnSubmitCalled to true to prevent any further submits. When we send a file this doesn't refresh the page so we need to manually set this variable back to false.
On your button in the webpart set the OnClientClick to a function in your javascript for the page.

 <asp:Button ID="generateExcel" runat="server" Text="Export Excel" 
OnClick="generateExcel_Click" CssClass="rptSubmitButton"
OnClientClick="javascript:setFormSubmitToFalse()" />

Then in the javascript I have this function.

function setFormSubmitToFalse() {
    setTimeout(function () { _spFormOnSubmitCalled = false; }, 3000);
    return true;
}

The 3 second pause I found was necessary because otherwise I was setting the variable before sharepoint set it. This way I let sharepoint set it normally then I set it back to false right after.

in C#

SharePoint registers a JavaScript "on submit" handler. In this handler the global variable _spFormOnSubmitCalled is set to true. SharePoint uses this variable to check if a submit was executed and prevents any further submits. Since your "download postback" does not refresh the page this variable remains true. With the effect that that all other buttons stop working.
As a workaround you can set this variable to false in a client click handler on your download button:

Button btn = new Button();
btn.Text = "Download";
btn.Click += DownloadButton_Click;

// set the client click handler
btn.OnClientClick = "window.setTimeout(function() { _spFormOnSubmitCalled = false; }, 10);"