Sharepoint 2010 解决DFWP - Unable to display this Web Part 的问题

Example:
  public class customDFWP : DataFormWebPart
    {
        public override bool IsGhosted
        {
            get
            {
                return true;
            }
        }
        public override bool CanHaveServerControls
        {
            get
            {
                return true;
            }
        }
    }

2) Add a safe control entry to the web.config
Example:

3) Add the following to the element of the web.config
Example:

4) Register the assembly on the form page.
Example: <%@ Register tagprefix="customDFWP" namespace="customDFWP" assembly="customDFWP, Version=1.0.0.0, Culture=neutral, PublicKeyToken=963f869a440db619" %>

5) On the form page find and replace it with the new custom tag.
Example: