c# - Value cannot be null. Parameter name: entity -

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this question has answer here:

i have following view (basic "edit" template)

  @model successstories.models.testimonials    @using (html.beginform())  {      @html.antiforgerytoken()            <div class="form-horizontal">          <h4>testimonials</h4>          <hr />          @html.validationsummary(true, "", new { @class = "text-danger" })          @html.hiddenfor(model => model.id)            <div class="form-group">              @html.labelfor(model => model.testimonial, htmlattributes: new { @class = "control-label col-md-2" })              <div class="col-md-10">                  @html.editorfor(model => model.testimonial, new { htmlattributes = new { @class = "form-control" } })                  @html.validationmessagefor(model => model.testimonial, "", new { @class = "text-danger" })              </div>          </div>            <div class="form-group">              <div class="col-md-offset-2 col-md-10">                  <input type="submit" value="save" class="btn btn-default" />              </div>          </div>      </div>  }    <div>      @html.actionlink("back list", "index")  </div>

and following actionresult in controller:

[httpget]     public actionresult edit(int id)     {             testimonialscontext testcontext = new testimonialscontext();             testimonials testimonials = testcontext.testimonialcontext.find(id);             return view(testimonials);       }      [httppost]     public actionresult edit(testimonials testimonial)     {         testimonialscontext testcontext = new testimonialscontext();         testcontext.entry(testimonial).state = entitystate.modified;         testcontext.savechanges();          return redirecttoaction("index");     }

the error on line:

testcontext.entry(testimonial).state = entitystate.modified;

the error "value cannot null. parameter name: entity

description: unhandled exception occurred during execution of current web request. please review stack trace more information error , originated in code.

exception details: system.argumentnullexception: value cannot null. parameter name: entity"

please help. i've looked can't find solution work me. thanks!

thanks everyone. figured out way fix it, based on telling me null.

        [httppost, actionname("edit")]     public actionresult editconfirmed(int id, string testimonial)      {         testimonialscontext testcontext = new testimonialscontext();         testimonials testimonial = testcontext.testimonialcontext.find(id);         testimonial.testimonial = testimonial;         testcontext.entry(testimonial).state = entitystate.modified;         testcontext.savechanges();         return redirecttoaction("index");     }

testimonial name of input box, same name entry in database table.


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