title: Discarding changes with a DataGridView BindingSource to EF
body: <p>I have a little problem with my windows form app.
  Two forms: Parent Form - here I have DataGridView which presents list of Company. From here, I can open another form, CompanyForm, where you can add or edit selected Company. Add options work fine but when I edit company and want to discard changes, on Parent Form selected row was changed although I don't save change on my context. Someone can help me?</p>
  
  <p>ParentForm:</p>
  
  <pre><code>private void CompaniesForm_Load(object sender, EventArgs e)
      {
          using (var connect = new ContactEntities())
          {
              companyBindingSource.DataSource = connect.Companies.ToList();
          }
      }
  </code></pre>
  
  <p>Button Edit company:</p>
  
  <pre><code>private void buttonEditCompany_Click(object sender, EventArgs e)
      {
          CompanyForm company = new CompanyForm();
          company.MdiParent = this.MdiParent;
          company.Company = (Company)companyBindingSource.Current;
          company.Show();
      }
  </code></pre>
  
  <p>CompanyForm:</p>
  
  <pre><code>public Company Company { get; set; }    
  private void CompanyForm_Load(object sender, EventArgs e)
          {
              using (var connect = new ContactEntities())
              { 
                  companyBindingSource.DataSource = Company;
              }
          }
  </code></pre>
  
  <p>As you can see, I use bindingsource and I don't know why grid it was automatically updates.</p>