如何解决“报告查看器 Web 控件 HTTP 处理程序尚未在应用程序的 web.config 文件中注册”

Question

When working with an ASP.NET application, you receive the following error when attempting to view a page with the Microsoft ReportViewer control:

The Report Viewer Web Control HTTP Handler has not been registered in the application's 
web.config file.  Add <add verb="*" path="Reserved.ReportViewerWebControl.axd" type = 
"Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=9.0.0.0, 
Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" /> to the system.web/httpHandlers section of the web.config file

Answer 1

The solution has two steps.

Find the "system.webServer" section of the web.config and add the following lines to the "handlers" section. If your web.config doesn't have a "handlers" section, add it along with the new lines:

<system.webServer>
    <handlers>
        <!-- Add these lines -->
        <add name="ReportViewerWebControlHandler" preCondition="integratedMode" verb="*" path="Reserved.ReportViewerWebControl.axd" type="Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=9.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
        <validation validateIntegratedModeConfiguration="false"/>
    </handlers>
</system.webServer>

Then, Find the "system.web" section of the web.config and add the following lines to the "httpHandlers" section.

  <system.web>
    <httpHandlers>
      <!-- Add this line -->
      <add verb="*" path="Reserved.ReportViewerWebControl.axd" type="Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=9.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
    </httpHandlers>
  <system.web>