changing column header text?

rmanapul · August 24th, 2012, 04:07 AM

sir when i used .HeaderText an error says "HeaderText is not a member of System.Web.Ui.WebControls.TableCell." i changed it to .Text and it worked. thanks for the code! Now it's running :)

Imar · August 24th, 2012, 04:18 AM

You're correct. My mistake. I updated the original post as well.

Quote:

May I ask what you're trying to accomplish? Is there any reason why you're not explicitly defining the columns in the GridView and instead rely on run-time discovery? Also any reason for not using the EntityDataSource to handle binding, paging and sorting for you?

Want to comment on this? I am wondering why you're doing what you're doing...

Imar

rmanapul · August 28th, 2012, 08:45 PM

I dont know how to control the binding in the datasource controls using if-else. is there a way on how to manipulate the datasource controls programmatically? Im using the things i learned from your book in creating an Online Alumni System for our school. Our College hired me as their web developer and web administrator. thanks for the things i learned from your book and i hope you publish more in the future :)

Imar · August 29th, 2012, 04:27 AM

Quote:

is there a way on how to manipulate the datasource controls programmatically?

Yes, but you need to provide more info about what it is you want to do.

Cheers,

Imar

rmanapul · August 29th, 2012, 04:29 AM

for example you can program the datasource control to bind to a specific table based on the arguments in the if-else statement. is that possible?

Imar · August 29th, 2012, 04:30 AM

I am not sure I get this. Can you describe the use case? Why does this have to be so dynamic? I am not saying you don't need this, but you may be making this more complicated that needed.

Cheers,

Imar

rmanapul · August 29th, 2012, 04:47 AM

for example,

using values to change the contents of gridview. i can do it without the help of datasource control

Code:

If Province_Ddl.SelectedValue = "Province1" Then
                Dim Province1Municipality = From city In myEntities.CityTbls
                                        Where city.Province = "Province1"
                                        Order By city.City
                                        Select city.City

                cityGridView.DataSource = Province1Municipality
                cityGridView.DataBind()

ElseIf Province_Ddl.SelectedValue = "Province2" Then
                Dim Province2Municipality = From city In myEntities.CityTbls
                                        Where city.Province = "Province2"
                                        Order By city.City
                                        Select city.City

                cityGridView.DataSource = Province2Municipality
                cityGridView.DataBind()

ElseIf Province_Ddl.SelectedValue = "Province3" Then
                Dim Province3Municipality = From city In myEntities.CityTbls
                                        Where city.Province = "Province3"
                                        Order By city.City
                                        Select city.City

                cityGridView.DataSource = Province3Municipality
                cityGridView.DataBind()

.
.
.
.
.
.
End If

by the way, our country has more than 75 provinces so i handcoded and copy-pasted them one by one.

Imar · August 29th, 2012, 05:26 AM

Quote:

by the way, our country has more than 75 provinces so i handcoded and copy-pasted them one by one.

Really? Wow! What a nightmare that must be if you ever want to change something.

What about this:

Code:

Dim ProvinceMunicipalities = From city In myEntities.CityTbls
                                        Where city.Province = Province_Ddl.SelectedValue 
                                        Order By city.City
                                        Select city.City

                cityGridView.DataSource = ProvinceMunicipalities
                cityGridView.DataBind()

Not it works for all 75 of them, regardless of what you choose in the DDL.

To make this even easier, set up the data source for the GridView to use the SelectedValue of the DropDownList. This way, you can accomplsih the exact same thing without manual coding and just a few server controls.

You find an example that demonstrates exactly this (using Genres and Reviews) on page 446 and further in the section "Filtering Data".

Cheers,

Imar

rmanapul · August 29th, 2012, 07:27 PM

wow thanks. i didn't know that controls can also be called in LINQ queries lol. im going to try that :)