Combobox in datagrid: Set the ItemSource at Run time

11-03-2009 5:13 PM |

I have a datagrid with one of the columns as DataTemplate (ComboBox). I have to set the ItemSource of Combobox at runtime.

I tried to follow the example of

http://weblogs.asp.net/manishdalal/archive/2008/09/28/combobox-in-datagrid.aspx

but here the list of the cities in static.

Could anybody let me know if they tried a similar scenario. Please let me know

Re: Combobox in datagrid: Set the ItemSource at Run time

11-03-2009 5:15 PM |

The answer will depend on what you're trying to set the itemsource to. Are you trying to bind it? Does it relate to the item?

Re: Combobox in datagrid: Set the ItemSource at Run time

11-03-2009 5:22 PM |

I have to bind it so that the user can change from the combo box. I have the relation established but not able to bind the combobox list at runtime. The default display item shows up fine.

Re: Combobox in datagrid: Set the ItemSource at Run time

11-03-2009 5:28 PM |

                        <my:DataGridTemplateColumn Header="Material " SortMemberPath="MaterialInfo.MatDesc">
                            <my:DataGridTemplateColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBlock Text="{Binding MaterialInfo.MatDesc}" />
                                </DataTemplate>
                            </my:DataGridTemplateColumn.CellTemplate>
                            <my:DataGridTemplateColumn.CellEditingTemplate>
                                <DataTemplate>
                                    <ComboBox ItemsSource="{Binding MaterialList, Source={StaticResource materialListProvider}}" 
                                      SelectedItem="{Binding MaterialInfo, Mode=TwoWay}" 
                                      DisplayMemberPath="MatDesc"  
                                      src:ComboBoxService.ForceOpen="true"
                                    />
                                </DataTemplate>
                            </my:DataGridTemplateColumn.CellEditingTemplate>
                        </my:DataGridTemplateColumn>

 That is my DataGridTemplateColumn. The materialListProvider is defined as in the UserResources as

<UserControl.Resources>
        <src:MaterialListProvider x:Key="materialListProvider"/>
    </UserControl.Resources>

The MaterialListProvider is a class that I defined with MaterialList as a function that returns a list of Materials. The issue is that I have to generate MaterialList during runtime (so thinking of defining an instance of MaterialListProvider and setting up the values). But that is not binding to the combobox( the dropdown shows empty on edit) :(

Re: Combobox in datagrid: Set the ItemSource at Run time

11-03-2009 5:35 PM |

Can you confirm that property MaterialList is being accessed?  Does this property make a call to a server somewhere?  If so, what do you do when this call completes?

Re: Combobox in datagrid: Set the ItemSource at Run time

11-03-2009 6:10 PM |

I intially set the MaterialList property to return from something like

{

 get

 {

return new List<Material> {

new Material() { MatDesc = "Mat1", MaterialId = 1},

 new Material() { MatDesc = Mat2 ",  MaterialId = 2},

 new Material() { MatDesc = "3", salMaterialId = 3}

 };

 }

 }

This one worked fine.

Now I have a to set the list from a call from database at runtime. I am thinking of making a instance of the MaterialProvider class and settign the value of the MaterialInfo from the list retunred from database but don't know how to set it to the combobox from the instance of the MaterialProvider.

Re: Re: Combobox in datagrid: Set the ItemSource at Run time

11-03-2009 6:24 PM |

Make sure your MaterialListProvider class implement INotifyPropertyChanged and that once you get the list from the database you fire the PropertyChanged event and specify MaterialList as the property name.

Re: Re: Combobox in datagrid: Set the ItemSource at Run time

11-03-2009 7:58 PM |

Bryant,

But how do I bind the objMaterialListProvider.MaterialList to the ComboBox of the  DataTemplate. That is where I am struck right now.

Re: Re: Re: Combobox in datagrid: Set the ItemSource at Run time

11-04-2009 3:57 PM |

It looks like your binding is setup correctly. Is it not working?

Re: Re: Re: Combobox in datagrid: Set the ItemSource at Run time

11-05-2009 3:36 PM |

It was working for the predefined list of materials. My goal is to bind to a list which is dynamic. tried a couple of ways but no luck so far

Re: Combobox in datagrid: Set the ItemSource at Run time

11-06-2009 2:43 AM |

HI,

   Are you trying to bind comboBox using codeBehind. If that is the case. You could try to add a loaded event handler to the combox. And in the handler assign the comboBox's itemsSource to what you want.

  If that is not the case, you may provide more information to us so that we could get a clear view of your scenerio. Then we can find you a more satisfied solution.

Best Regards