c# - How to have custom control in DataGridView display object's value? -

i have sample project located here.

the project has main form form1 user can enter customers in datagridview. customertype column custom control , when user clicks button, search form form2 pops up.

the search form populated list of type customertype. user can select record double-clicking on row, , object should set in custom control. datagridview should display description property in background each cell should hold value (ie. customertype instance).

the relevant code located in following classes:

the column class:

public class datagridviewcustomertypecolumn : datagridviewcolumn {     public datagridviewcustomertypecolumn()         : base(new customertypecell())     { }      public override datagridviewcell celltemplate     {         { return base.celltemplate; }         set         {             if (value != null && !value.gettype().isassignablefrom(typeof(customertypecell)))             {                 throw new invalidcastexception("should customertypecell.");             }              base.celltemplate = value;         }     } } 

the cell class:

public class customertypecell : datagridviewtextboxcell {     public customertypecell()         : base()     { }      public override void initializeeditingcontrol(int rowindex, object initialformattedvalue, datagridviewcellstyle datagridviewcellstyle)     {         base.initializeeditingcontrol(rowindex, initialformattedvalue, datagridviewcellstyle);          customertypesearch ctl = datagridview.editingcontrol customertypesearch;          if (this.value == null)             ctl.value = (customertype)this.defaultnewrowvalue;         else             ctl.value = (customertype)this.value;     }      public override type edittype     {         { return typeof(customertypesearch); }     }      public override type valuetype     {         { return typeof(customertype); }     }      public override object defaultnewrowvalue     {         { return null; }     } } 

and custom control:

public partial class customertypesearch : usercontrol, idatagridvieweditingcontrol {     private datagridview datagridview;     private int rowindex;     private bool valuechanged = false;     private customertype value;      public customertypesearch()     {         initializecomponent();     }      public customertype value     {         { return this.value; }         set          {              this.value = value;              if (value != null)                 textboxsearch.text = value.description;             else                 textboxsearch.clear();         }     }      private void buttonsearch_click(object sender, eventargs e)     {         form2 f = new form2();          dialogresult dr = f.showdialog(this);          if (dr == dialogresult.ok)         {             value = f.selectedvalue;         }     }      #region idatagridvieweditingcontrol implementation      public object editingcontrolformattedvalue     {                  {             if (this.value != null)                 return this.value.description;             else                 return null;         }         set          {              if (this.value != null)                 this.value.description = (string)value;          }     }      public object geteditingcontrolformattedvalue(datagridviewdataerrorcontexts context)     {         return editingcontrolformattedvalue;     }      public void applycellstyletoeditingcontrol(datagridviewcellstyle datagridviewcellstyle)     {         this.borderstyle = borderstyle.none;         this.font = datagridviewcellstyle.font;     }      public int editingcontrolrowindex     {         { return rowindex; }         set { rowindex = value; }     }      public bool editingcontrolwantsinputkey(keys key, bool datagridviewwantsinputkey)     {         return false;     }      public void prepareeditingcontrolforedit(bool selectall)     {         //no preparation needs done      }      public bool repositioneditingcontrolonvaluechange     {         { return false; }     }      public datagridview editingcontroldatagridview     {         { return datagridview; }         set { datagridview = value; }     }      public bool editingcontrolvaluechanged     {         { return valuechanged; }         set { valuechanged = value; }     }      public cursor editingpanelcursor     {         { return base.cursor; }     }      #endregion      private void customertypesearch_resize(object sender, eventargs e)     {         buttonsearch.left = this.width - buttonsearch.width;         textboxsearch.width = buttonsearch.left;     } } 

however, datagridview not displaying text , not keeping customertype value each cell.

what missing?

first, override tostring() method customertype class.

second, avoid parsing errors, modify following method in customertypesearch class :

public customertype value {     { return this.value; }     set     {         this.value = value;          if (value != null)             textboxsearch.text = value.description;         else             textboxsearch.clear();          valuechanged = true;         if ((editingcontroldatagridview.currentcell customertypecell) != null)             (editingcontroldatagridview.currentcell customertypecell).value = value;     } } 

then, add function custormertypecell class :

protected override bool setvalue(int rowindex, object value) {     if (value != null)         return base.setvalue(rowindex, value);     return false; } 

finally, add handle data errors :

private void datagridview_dataerror(object sender, datagridviewdataerroreventargs e) {     e.cancel = false; }