Redirect a Response on a Callback Exception

• Dec 27, 2023

When a callback exception occurs, you can redirect the application to another web resource in the following ways:

• Use the Web.config’s callbackErrorRedirectUrl option to specify a page where the response is redirected.

  XML

  <configuration>
    <!-- ... -->
    <devExpress>
      <!-- ... -->
      <errors callbackErrorRedirectUrl="~/Error.aspx" />
    </devExpress>
  </configuration>
  

• Use the static CallbackError event to delegate callback exception handling to the Application_Error event handler. In the handler, call the RedirectOnCallback(String) method to redirect the application to another web resource.

  Global.asax.cs

  protected void Application_Start(object sender, EventArgs e) {
      DevExpress.Web.ASPxWebControl.CallbackError += Application_Error;
  }
  
  protected void Application_Error(object sender, EventArgs e) {
      DevExpress.Web.ASPxWebControl.RedirectOnCallback("Error.aspx");
  }
  

  Global.asax.vb

  Protected Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
      DevExpress.Web.ASPxWebControl.CallbackError += AddressOf Application_Error
  End Sub
  
  Protected Sub Application_Error(ByVal sender As Object, ByVal e As EventArgs)
      DevExpress.Web.ASPxWebControl.RedirectOnCallback("Error.aspx")
  End Sub
  

On the redirection page, you can call the static GetCallbackErrorMessage() method to obtain exception-related information.

Error.aspx.cs

public partial class Error : Page {
    protected void Page_Load(object sender, EventArgs e) {
        string errorMessage = ASPxWebControl.GetCallbackErrorMessage();
        Response.Output.Write(errorMessage);
    }
}

Error.aspx.vb

Public Partial Class [Error]
    Inherits Page
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
        Dim errorMessage As String = ASPxWebControl.GetCallbackErrorMessage()
        Response.Output.Write(errorMessage)
    End Sub
End Class